Categories
Chemotherapeutic Agents Nursing Pharmacology

Antiprotozoal Agents

Antiprotozoal Agents

Causes of Protozoal Infections

  • Insect bites
    • Malaria
    • Trypanosomiasis
    • Leishmaniasis
  • Ingestion or contact with the causal organism
    • Amebiasis
    • Giardiasis
    • Trichomoniasis

Protozoal Parasites Identified as Causes of Malaria

  • Plasmodium falciparum
    • Considered the most dangerous type of protozoan
  • Plasmodium vivax
    • Milder form of the disease; seldom results in death
  • Plasmodium malariae
    • Endemic in tropical countries; mild symptoms
  • Plasmodium ovale
    • Rarely seen; in the process of being eradicated

Life Cycle of Plasmodium

Life Cycle of Plasmodium
Life Cycle of Plasmodium

Antimalarials

  • Chloroquine (Aralen)
    • Prevention and treatment of plasmodial malaria; treatment of extraintestinal amebiasis
  • Halofantrine (Halfan)
    • Treatment of plasmodial malaria in combination with other drugs
  • Hydroxychloroquine (Plaquenil)
    • Treatment of plasmodial malaria in combination with other drugs (particularly primaquine)
  • Mefloquine (Lariam)
    • Prevention and treatment of plasmodial malaria in combination with other drugs
  • Primaquine (generic)
    • Prevention of relapses of Plasmodium vivax and Plasmodium malariae infections
    • Radical cure of P. vivax malaria
  • Pyrimethamine (Daraprim)
    • Prevention of plasmodial malaria in combination with other agents to suppress transmission
    • Treatment of toxoplasmosis
  • Quinine (generic)
    • Treatment of chloroquine-resistant plasmodial infections

Antimalarials—Action

  • Interrupt plasmodial reproduction of protein synthesis
  • Agents that do not appear to affect the sporozoites are used for prophylaxis

Antimalarials—Contraindications

  • Known allergy
  • Liver disease
  • Alcoholism
  • Lactation
  • Cautions
    • Retinal disease or damage
    • Psoriasis

Antimalarials—Adverse Effects

  • Headache
  • Dizziness
  • Fever
  • Chills
  • Malaise
  • Nausea
  • Vomiting
  • Hepatic dysfunction

Antimalarials—Drug-to-Drug Interactions

  • Quinine derivatives and quinine create risk for cardiac toxicity
  • Antifolate drugs with pyrimethamine can increase risk of bone marrow suppression

Other Antiprotozoal Drugs

  • Actions
    • Inhibit DNA synthesis
  • Contraindications
    • Known allergy, pregnancy, CNS disease, and hepatic disease
  • Adverse reactions
    • Headache, dizziness, ataxia, nausea, vomiting, and diarrhea

Malaria

  • Signs and symptoms
    • Related to the destruction of red blood cells and toxicity to the liver
  • Treatment
    • Aims at attacking the parasite at the various stages of its development inside and outside the human body

Other Protozoal Infections

  • Amebiasis
  • Leishmaniasis
  • Trypanosomiasis
  • Trichomoniasis
  • Giardiasis
  • Pneumocystis carinii

Risk Factors for Protozoal Infections

  • Unsanitary conditions
  • Poor hygienic practices

Prototype Antiprotozoal Agent

Prototype Antiprotozoal Agent
Prototype Antiprotozoal Agent

Prototype Antifungal Agent

Prototype Antifungal Agent
Prototype Antifungal Agent

Use of Antifungals Across the Lifespan

Use of Antifungal Across the Lifespan
Use of Antifungal Across the Lifespan

Common Antiprotozoal Agents

  • Atovaquone (Mepron)
    • Especially active against PCP
  • Metronidazole (Flagyl, MetroGel, Noritate)
    • Treats amebiasis, trichomoniasis, and giardiasis
  • Pentamidine (Pentam 300, NebuPent)
    • Treats PCP, trypanosomiasis, and leishmaniasis
  • Tinidazole (Tindamax)
    • Treats trichomoniasis, giardiasis, and amebiasis

Nursing Considerations for Antimalarial Agents

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for Antiprotozoal Agents

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation
Categories
Theorists

Dorothea E. Orem

Dorothea E. Orem
Dorothea E. Orem

Person/Client:

A unity who can be viewed as functioning biologically, symbolically, and socially and who initiates  and performs self-care activities on own behalf in maintaining life, health and well-being; self-care activities deal with air, water, food elimination, activity and rest, solitude and social interaction, prevention of hazards to life and well-being, and promotion of human functioning.

Environment:

The environment is linked to the individual, forming an integrated and interactive system.

Health:

Health is a state that is characterized by soundness or wholeness of developed human structures and of bodily and mental functioning. It includes physical, psychologic, interpersonal, and social aspects. Well-being is used in the sense of individual’s perceived condition of existence. Well-being is a state characterized by experiences of contentment, pleasure and certain kinds  of happiness; by spiritual experiences; by movement toward fulfillment of one’s ideal; and by continuing personalization. Well-being is associated with health, with success in  personal endeavors, and with sufficiency of resources.

Nursing:

A helping or assisting service to persons who are wholly or partly dependent-infants, children and adults – when they, their parents, guardians, or other adults responsible for their care are no longer able to give  or supervise their care.  A creative effort of one human being to help another human being. Nursing is deliberate action, a function of the practical intelligence of nurses, and action to bring about humanely desirable conditions in persons and their environments. It is distinguished from other human services and other forms of care by its focus on human beings.

Orem’s Self-Care Deficit Theory

Dorothy Orem’s self-care deficit theory, published first in 1971, has been widely accepted by the nursing community. It includes three related theories of self-care, self-care deficit, and nursing system. Self-care theory postulates that self-care and the self-care of dependents are learned behaviors that individuals initiate and perform on theri own behalf to maintian life, health, and well-being. The individual’s ability to perform self care is called self-care agency. Adults care for themselves, whereas infants, the aged, the ill, and the disabled require assistance with self-care activities.

These are three kinds of self-care requisites:

1. Universal requisites, common to all people, include the maintenance of air, water, food, elimination, activity and rest, solitude and social interaction; prevention of hazards to life and well-being; and the promotion of human functioning.

2. Developmental requisites are those associated with conditions that promote known developmental processes throughout the life cycle.

3. Health deviation requisites relates to defects and deviations from normal structure and integrity that impair an individual’s ability to perform self-care.

Self-care deficit theory asserts that people benefit from nursing because they have health-related limitations in providing self-care. Limitations may result from illness, injury, of form the effects of medical tests or treatments.Two variables affect these deficits: self-care agency (ability) and therapeutic self-care demands (the measures of care required to meet existing requisites). Self-care deficit results when self-care agency is not adequate to meet he known self-care demand.

Nursing system theory postulates that nursing systems form when nurses prescribe, design, and provide nursing that regulates the individual’s self-care capabilities and meets therapeutic self-care requirements. Three types of nursing systems are identified:

1. Wholly compensatory systems are required for individuals unable to control and monitor their environment and process information.

2. Partially compensatory systems are designed for individuals who are unable to perform some (but not all) self-care activities.

3. Supportive-educative (developmental) systems are designed for persons who need to learn to perform self-care measures ans need assistance to do so.

 

Reference:

Kozier, Barbara et.al Fundamentals of Nursing 5th edition

Addison-Wesley Publishing Company, Inc 1998 p.51

Categories
Theorists

Dorothy E. Johnson

Dorothy E. Johnson
Dorothy E. Johnson

Behavioral System Model (1959,1968,1974,1980)

Person/Client:

A behavioral system composed of seven subsystems: affiliative, achievement, dependence, aggressive, eliminative, ingestive, and sexual.

Environment:

Consists of all factors that are not part of the individual’s behavioral system but that influence the system and some of which can be manipulated by the nurse to achieve the health goal of the client. The individual links to and interacts with the environment.

Health:

Health is an elusive, dynamic state of influenced by biologic, psychologic, and social factors. Health is reflected by the organization, interdependence, and integration of the subsystem. Human attempt to achieve a balance in this system; this balance leads to functional behavior. A lack of balance in the structural or functional requirements of the subsystem leads to a poor health.

Nursing:

An external regulatory force that acts to preserve the organization and integration of the client’s behavior at an optimal level under those conditions in which the behavior constitutes a threat to physical or social health or in which illness is found.

 

Johnson’s Behavioral System Model

Dorothy Johnson used her observations of behavior over many years to formulate a general theory of man as a behavioral system. The theory was originally presented orally in 1968 but was not published until 1980. Johnson defines a system as a whole that functions as a whole by virtue of the interdependence of its parts. Individuals strive to maintian stability and balance in these parts through adjustments and adaptations to the forces that impinge on them. A behavioral system is patterned, repetitive, and purposeful.

Johnson’s key concepts describe the individual  as a behavioral system composed of seven subsystems:

1. The attachment-affiliative subsystem provides survival and security. Its consequences are social inclusion, intimacy, and the formation and  maintenance of a strong social bond.

2. The dependency subsystem promotes helping behavior that calls for a nurturing response. Its consequences are approval, attention or recognition, and p[physical assistance.

3. The ingestive subsystem satisfies appetite. It is governed by social and psychologic considerations as well as biologic.

4. The eliminative subsystem excrete body wastes.

5. The sexual subsystem functions dually for procreation and gratification.

6. The achievement subsystem attempts to manipulate the environment. It controls or masters an aspect of the self or environment to some standard of excellence.

7. The aggressive subsystem protects and preserves the self and society within the limits imposed by society.

Each of the above subsystem has the same functional requirements: protection, nurturance, and stimulation. The subsystems’ responses are developed through motivation, experience, and learning and are influenced by biopsychosocial factors.

Other concepts associated with Johnson’s model are equilibrium, a stabilized more or less transitory resting state in which the individual is in harmony with the self and the environment; tension, a state of being stretched or strained; and stressors, internal or external stimuli that produce tension ans result in a degree of instability.

 

Reference:

Kozier, Barbara Fundamental of Nursing 5th edition

Addison-Wesley Publishing Company, Inc 1998 p.49

Categories
Theorists

Betty Neuman

Betty Neuman
Betty Neuman

Health Care System Model

(1972,1974,1980,

1982,1989)

Person/Client:

Open system consisting of a basic structure or central core of survival factors surrounded by concentric rings that are bounded by lines of resistance , a normal line of defense, and a flexible line of defense. The total person is a composite of physiologic, psychologic, sociocultural, and developmental variables.

Environment:

Both internal and external environments exists and a person maintains varying degrees of harmony and balance between them. It is all factors affecting and affected by the system.

Health:

Wellness is the condition in which all parts and sub-parts of an individual are in harmony with the whole system. Wholeness is based on interrelationships of variables that determine the resistance of an individual to any stressor. Illness indicates lack of harmony among the parts and sub-parts of the system of the individual. Health is viewed as a point along a continuum from wellness to illness; health is dynamic. Optimal wellness or stability indicates that all a person’s needs are being met. A reduced state of wellness is the result of unmet systemic needs. The individual is in a dynamic state of wellness-illness, in varying degrees, at any given time.

 

Neuman’s Health Care Systems Model

Betty Neuman’s systems model, first published in 1972, is based on the individuals relationship to stress, the reaction to it, and reconstitution factors that are dynamic in nature. Reconstitution is the state of adaptation to stressors.

Neuman views the client as an open system consisting of a basic structure or central core of energy sources surrounded by two concentric boundaries or rings referred to as lines of resistance. The two lines of resistance represent internal factors that help the client defend against a stressor. The inner or normal line of defense represents the person’s state of equilibrium of the state of adaptation developed and maintained over time  and considered normal for that person. The flexible line of defense is dynamic and can be rapidly altered over a short period of time. It is a protective buffer that prevents stressors from penetrating  the normal line of defense.

The nurse’s focus is all the variables affecting an individual’s response to stressors. Nursing interventions are carried out on three preventive levels:

1. Primary prevention identifies risk factors, attempts to eliminate the stressor, and focuses on protecting the normal line of defense and strengthening the flexible line of defense. A reaction has not yet occurred, but the degree of risk is known.

2. Secondary prevention relates to interventions or active treatment initiated after symptoms have occurred. The focus is to strengthen internal lines of resistance, reduce the reaction, and increase resistance factors.

3. Tertiary prevention refers to intervention following that in the secondary stage. It focuses on readaptation and stability and protects reconstitution or return to wellness follwing treatment. The nurse emphasizes educating the client in strengthening resistance to stressors and ways to help prevent recurrence of reaction or regression.

Betty Neuman’s model of nursing has been widely accepted by the nursing community, nationally and internationally. it is applicable to a variety of nursing practice settings involving individuals, families, groups, and communities.

Reference:

Kozier, Barbara et.al Fundamentals of Nursing 5th edition

Addison-Wesley Publishing Company, Inc.1998 p.49

Categories
Theorists

Imogene King

Imogene King
Imogene King

Goal Attainment Theory (1971,1981,1986,1987,1989)

Person/Client:

Three interacting systems; individuals (personal system), groups (interpersonal system), and society (social system); the personal system is a unified, complex, whole self who perceives, thinks, desires, imagines, decides, identifies goals, and selects means to achieve them.

Environment:

Adjustments to life and health are influenced by an individual;s interactions with environment. The environment is constantly changing.

Health:

A dynamic state in the life cycle; illness is an interference in the life cycle. Health implies continuous adaptation to stress in the internal and external environment through the use of one’s resources to achieve a maximum potential for daily living.

Nursing:

A helping profession that assists individuals and groups in society to attain, maintain, and restore health. If this is not possible, nurses help individuals die with dignity. Nursing is perceiving, thinking, relating, judging and acting a vis-avis the behavior of individuals who come to a nursing situation.  A nursing situation is the immediate environment, spatial and temporal reality, in which nurse and client establish a relationship to cope with health state and adjust to changes in activities of daily living if the situation demands adjustment. It is an interpersonal process of action, reaction, interaction, and transaction whereby nurse and client share information about their perceptions in the nursing situation.

King’s Goal Attainment Theory

Imogene King’s theory of goal attainment, first published in 1971, was derived from conceptual framework of three dynamic interacting systems; (a) personal systems (individuals), (b) interpersonal systems (groups), and social systems (society). Key concepts are identified for each system as follows:

1. Personal system concepts: perception, self, body image, growth and development, space and time

2. Interpersonal system concepts: interaction, communication, transaction, role and stress

3. Social system concepts: organization, authority, power, status, and decision making.

The client ans nurse are personal systems subsystems within interpersonal and social systems. To identify problems and to establish goals, the nurse and client perceive one another, act and react, interact, and transact. Transactions are defined as purposeful interactions that lead to goal attainment. Transactions have the following characteristics:

1. They are basic to goal attainment and include social exchange, bargaining and negotiating, and sharing a frame of reference toward mutual goal setting.

2. They require perceptual accuracy in nurse-client interactions and congruence between role performance and role expectation for nurse and client.

3. They lead to goal attainment, satisfaction, effective care, and enhanced growth and development.

King postulates seven hypothesis in goal attainment theory:

1. Perceptual congruence in nurse-client interactions increases mutual goal setting.

2. Communication increases mutual goal setting between nurses and clients and leads to satisfactions.

3. Satisfaction in nurses and clients increase goal attainment.

4. goal attainment decreases stress and anxiety in nursing situations.

5. Goal attainment increases client learning and coping ability in nursing situations.

6. Role conflict experienced by clients, nurses, or both decreases transactions in nurse-client interactions.

7. Congruence in role expectations and role performance in creases transactions in nurse-client interactions.

King’s theory highlights the importance of the participation of all individuals in decision making and deals with the choices, alternatives, and outcomes of nursing care. The theory offers insight into nurses’ interactions with individuals and groups within the environment t.

 

Reference:

Kozier, Barbara et.al Fundamentals of Nursing  5th edition

Addison-Wesley Publishing Company, Inc pp.48-49

Categories
Chemotherapeutic Agents Nursing Pharmacology

Antifungal Agents

Antifungal Agents

What Is a Fungus?

  • Fungus
    • Composed of a rigid cell wall made up of chitin and various polysaccharides, and a cell membrane containing ergosterol
    • Protective layers of the fungal cell make the organism resistant to antibiotics

Patients Susceptible to Fungal Infections

  • Patients with AIDS and AIDS-related complex (ARC)
  • Patients taking immunosuppressant drugs
  • Patients who have undergone transplantation surgery or cancer treatment
  • Members of growing elderly population no longer protected from environmental fungi

Culture

  • Culture is needed prior to prescribing antifungal agents
  • Patients on antifungal agents are immuno-compromised at onset

Amphotericin B Indications

  • Aspergillosis
  • Leishmaniasis
  • Cryptococcosis
  • Blastomycosis
  • Moniliasis
  • Coccidioidomycosis
  • Histoplasmosis
  • Mucormycosis
  • Candida infections (topically)

Amphotericin B

  • Indications: progressive, potentially fatal fungal infections
  • Pharmacokinetics: IV form, excreted in the urine
  • Contraindication: kidney disease
  • Adverse reaction: kidney failure

Systemic Antifungal Agents

  • Caspofungin (Cancidas) (IV)
    • Approved for the treatment of invasive aspergillosis in patients who are refractory to other treatments
  • Flucytosine (Ancobon) (oral)
    • Less toxic drug used for the treatment of systemic infections caused by Candida or Cryptococcus
  • Nystatin (Mycostatin, Nilstat) (oral)
    • Used for the treatment of intestinal candidiasis; also available in a number of topical preparations

Voriconazole & Terbinafine

  • Newer agents
  • Voriconazole (Vfend)
    • Available in oral and IV forms
    • Treats invasive aspergillosis and serious infections caused by Scedosporium apiospermum and Fusarium species
  • Terbinafine (Lamisil)
    • Blocks the formation of ergosterol
    • Inhibits a CYP2D6 enzyme system
    • Oral drug for the treatment of onychomycosis of the toenail or fingernail

Azoles

  • Newer class of drugs used to treat systemic fungal infections
  • Less toxic than amphotericin B
  • Less effective than amphotericin B

Ketoconazole (Nizoral)

  • Used orally to treat many of the same mycoses as amphotericin B
  • Works by blocking the activity of a steroid in the fungal wall
  • Has side effect of blocking the activity of human steroids, including testosterone and cortisol
  • Pharmacokinetics: absorbed from the GI tract, metabolized in the liver, excreted in the feces
  • Contraindications: not drug of choice for patients with endocrine or fertility problems
  • Adverse reaction: hepatic toxicity
  • Drug-to-drug interactions: many

Fluconazole (Diflucan)

  • Not associated with the endocrine problems seen with ketoconazole
  • Used to treat candidiasis, cryptococcal meningitis, and other systemic fungal infections
  • Prophylactic agent for reducing the incidence of candidiasis in bone marrow transplant recipients
  • Pharmacokinetics: available in oral and IV preparations, excreted unchanged in the urine
  • Contraindications: renal dysfunction
  • Adverse reactions:
  • Drug-to-drug interactions: inhibits CYP450 and may be associated with drug-to-drug interactions

Itraconazole (Sporanox)

  • An oral agent used for the treatment of assorted systemic mycoses
  • Associated with hepatic failure
  • Slowly absorbed from the GI tract, it is metabolized in the liver by the CYP450 system
  • Excreted in the urine and feces

Sites of Action of Antifungal Agents

Sites of Action of Antifungal Agents
Sites of Action of Antifungal Agents

Overall Contraindications to Systemic Antifungal Agents

  • Anyone with a known allergy
  • Pregnant or lactating women (with the exception of terbinafine for life-threatening infections)
  • Patients with renal or liver disease
    • Drug metabolism or excretion may be altered, or condition may worsen as a result of the actions of the drug

Overall Adverse Reactions to Systemic Antifungal Agents

  • CNS effects
    • Headache, dizziness, fever, shaking, and chills
  • GI effects
    • Nausea, vomiting, dyspepsia, and anorexia
  • Hepatic dysfunction
  • Dermatologic effects
    • Rash and pruritus associated with local irritation
  • Renal dysfunction

Topical Antifungal Infections

  • Caused by dermatophytes
  • Tinea infections (ringworm)
    • Athlete’s foot (tinea pedis)
    • Jock itch (tinea cruris)
  • Candida
    • Yeast infections of the mouth and vagina

Topical Antifungal Agents

  • Action
    • Work to alter the cell permeability of the fungus, causing prevention of replication and fungal death
  • Indication
    • Indicated only for local treatment of mycoses, including tinea infection
  • Contraindication/caution
    • Limited to known allergy to any antifungal agent
  • Adverse effects
    • Local effects include irritation, burning, rash, and swelling
    • When taken as a suppository or troche, nausea, vomiting, hepatic dysfunction, urinary frequency, burning, and change in sexual activity can occur
  • Drug-to-drug interactions
    • None reported

Prototype Antifungal Agent

Fluconazole
Fluconazole

Clotrimazole
Clotrimazole

Use of Antifungals Across the Lifespan

Drug Therapy Across the Lifespan
Drug Therapy Across the Lifespan

Nursing Considerations for Systemic Antifungal Agents

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for Topical Antifungal Agents

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation
Categories
Chemotherapeutic Agents Nursing Pharmacology

Antiviral Agents

Antiviral Agents

Viruses That Respond to Antiviral Therapy

  • Influenza A and some respiratory viruses
  • Herpes viruses
  • Cytomegalovirus (CMV)
  • Human immunodeficiency virus (HIV) that causes acquired immune deficiency syndrome (AIDS)
  • Some viruses that cause warts and certain eye infections

Antivirals Across the Lifespan

Antivirals Across the Lifespan
Antivirals Across the Lifespan

Characteristics of Common Viruses

  • Viral replication
    • A virus cannot replicate on its own
      • It must attach to and enter a host cell
      • It then uses the host cell’s energy to synthesize protein, DNA, and RNA
  • Viruses are difficult to kill because they live inside our cells
    • Any drug that kills a virus may also kill our cells

Stages of Virus Replication

Stages of Virus Replication
Stages of Virus Replication

Characteristics of Antiviral Drugs

  • Able to enter the cells infected with virus
  • Interfere with viral nucleic acid synthesis and/or regulation
  • Some agents interfere with the ability of the virus to bind to cells
  • Some agents stimulate the body’s immune system

Common Respiratory Viruses

  • Influenza A
  • Influenza B
  • Respiratory syncytial virus

Signs & Symptoms of Respiratory Viruses

  • Cough
  • Fever
  • Inflammation of the nasal mucosa
  • Inflammation of the mucosa of the respiratory tract

Signs and Symptoms of Herpes Virus

  • Painful vesicles that often occur in clusters on skin, cornea, or mucous membranes
  • Usual course of primary disease is 2 weeks
  • Duration of recurrences varies

Signs and Symptoms of CMV

  • May be asymptomatic
  • Fatigue
  • Nausea
  • Jaundice
  • If contracted during pregnancy, can result in stillbirth, brain damage, or birth defects

Signs and Symptoms of HIV/AIDS

  • Attach helper T cells
  • Acute infection: fever, rash, and myalgia
  • Asymptomatic infection: follows acute infection; duration varies
  • Persistent generalized lymphadenopathy: adenopathy persists more than 3 months
  • Constitutional symptoms: fever lasting more than a month, involuntary weight loss, chronic fatigue
  • Neurologic disease: dementia
  • Secondary infections: pneumocystis carinii and disseminated herpes simplex

Influenza A & Respiratory Viruses

  • Action: prevent shedding of the viral protein coat
  • Pharmacokinetics: administered orally and excreted unchanged in the urine
  • Contraindications: allergy, pregnancy, and lactation
  • Adverse reactions: dizziness, insomnia, nausea, orthostatic hypotension
  • Drug-to-drug interactions: anticholinergic agents

Herpes & Cytomegalovirus

  • Action: inhibit viral DNA replication by competing with viral substrates to form shorter, noneffective DNA chains
  • Pharmacokinetics: administered orally, IV, or topically; excreted unchanged in the urine
  • Contraindications: pregnancy and lactation
  • Adverse reactions: nausea, vomiting, headache, rash, and hair loss
  • Drug-to drug-interactions: nephrotoxic drugs and zidovudine

Drugs Used to Treat HIV/AIDS

  • Reverse transcriptase inhibitors
  • Protease inhibitors
  • Nucleosides
  • Fusion inhibitors

Reverse Transcriptase Inhibitors

  • Action: bind directly to HIV reverse transcriptase, blocking both RNA- and DNA-dependent DNA polymerase activities
  • Pharmacokinetics: given orally, metabolized in the liver, and excreted in the urine
  • Contraindications: pregnancy and lactation
  • Adverse reactions: headache, nausea, vomiting, rash, chills, fever, and diarrhea

Protease Inhibitors

  • Action: block protease activity within the HIV virus
  • Pharmacokinetics: agents are teratogenic except for saquinavir
  • Contraindications: pregnancy and lactation

Nucleosides

  • Action: interfere with HIV replication by inhibiting cell protein synthesis
  • Pharmacokinetics: given orally or IV, metabolized in the liver, and excreted in the urine
  • Adverse reactions: HA, insomnia, dizziness, nausea, diarrhea, fever, and rash

Fusion Inhibitors

  • Action: prevent the fusion of the virus with the human cellular membrane
  • Pharmacokinetics: given sub-q, metabolized in the liver, recycled in the tissues, and not excreted
  • Contraindication: no true contraindication
  • Adverse reactions: HA, dizziness, myalgia, nausea, vomiting, and diarrhea
  • Drug-to-drug interactions: pimozide, rifampin, triazolam, midazolam, and oral contraceptives

Locally Active Antiviral Agents

  • Action: act on viruses by interfering with normal viral replication and metabolic processes
  • Pharmacokinetics: not absorbed systemically
  • Contraindication: allergy to the drug
  • Adverse reactions: local burning, stinging, and discomfort

Prototype of Respiratory Antiviral Agents

Rimantadine
Rimantadine

Prototype of Herpes and Cytomegalovirus Agents

Acyclovir
Acyclovir

Prototype of HIV/AIDS Antiviral Agents

Nevirapine
Nevirapine

 

Zidovidine
Zidovidine

Nursing Considerations for Respiratory Antiviral Therapy

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for Herpes Virus and Cytomegalovirus

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for HIV/AIDS Antiviral Therapy

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for Locally Active Antiviral Agents

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation
Categories
Chemotherapeutic Agents Nursing Pharmacology

Antibiotics

Antibiotics

Antibiotics

  • Antibiotics are defined as:
    • Chemicals that inhibit specific bacteria

Types of Antibiotics

  • Bacteriostatic
    • Substances that prevent the growth of bacteria
  • Bactericidal
    • Substances that kill bacteria directly

Signs of Infection

  • Fever
  • Lethargy
  • Slow-wave sleep induction
  • Classic signs of inflammation (redness, swelling, heat, and pain)

Goal of Antibiotic Therapy

  • Decrease the population of the invading bacteria to a point where the human immune system can effectively deal with the invaders

Selecting Treatment

  • Identification of the causative organism
  • Based on the culture report, an antibiotic is chosen that is known to be effective at treating the invading organism

Bacteria Classification

  • Gram-positive
    • The cell wall retains a stain or resists decolorization with alcohol
  • Gram-negative
    • The cell wall loses a stain or is decolorized by alcohol
  • Aerobic
    • Depend on oxygen for survival
  • Anaerobic
    • Do not use oxygen

Aminoglycosides

  • A group of powerful antibiotics used to treat serious infections caused by gram-negative aerobic bacilli
  • Common medications:
    • Amikacin (Amikin)
    • Gentamicin (Garamycin)
    • Kanamycin (Kantrex)
    • Neomycin (Mycifradin)
    • Streptomycin
    • Tobramycin (Nebcin, Tobrex)
  • Bactericidal
  • Indications: treatment of serious infections caused by susceptible bacteria
  • Action: inhibit protein synthesis in susceptible strains of gram-negative bacteria causing cell death
  • Pharmacokinetics
    • Poorly absorbed from the GI tract but rapidly absorbed after IM injection, reaching peak levels within 1 hour
    • Widely distributed throughout the body, crossing the placenta and entering breast milk
    • Excreted unchanged in the urine and have an average half-life of 2 to 3 hours
    • Depend on the kidney for excretion and are toxic to the kidney
  • Contraindications
    • Known allergies, renal or hepatic disease, and hearing loss
  • Adverse effects
    • Ototoxicity and nephrotoxicity are the most significant
  • Drug-to-drug interactions
  • Diuretics and neuromuscular blockers

Cephalosporins

  • Similar to penicillin in structure and activity
  • Action
    • Interfere with the cell-wall–building ability of bacteria when they divide
  • Indication
    • Treatment of infection caused by susceptible bacteria
  • Pharmacokinetics
    • Well absorbed from the GI tract
    • Metabolized in the liver, excreted in the urine
  • Contraindications
    • Allergies to cephalosporins or penicillin
  • Adverse effect
    • GI tract
  • Drug-to-drug interactions
    • Aminoglycosides, oral anticoagulants, and ETOH

Fluoroquinolones

  • Relatively new class of antibiotics with a broad spectrum of activity
  • Indications: treat infections caused by susceptible strains of gram-negative bacteria, including urinary tract, respiratory tract, and skin infections
  • Actions: interferes with DNA replication in susceptible gram-negative bacteria, preventing cell reproduction
  • Pharmacokinetics
    • Absorbed in the GI tract
    • Metabolized in the liver
    • Excreted in the urine and feces
  • Contraindications
    • Known allergy, pregnancy, and lactation
  • Adverse effects
    • Headache, dizziness, and GI upset
  • Drug-to-drug interactions
    • Antacids, quinidine, and theophylline

Macrolides

  • Antibiotics that interfere with protein synthesis in susceptible bacteria
  • Indications: treatment of respiratory, dermatologic, urinary tract, and GI infections caused by susceptible strains of bacteria
  • Actions: bind to cell membranes causing a change in protein function and cell death; can be bacteriostatic or bactericidal
  • Pharmacokinetics
    • Absorbed from the GI tract
    • Metabolized in the liver, excreted in the bile to feces
  • Contraindications
    • Allergy and hepatic dysfunction
  • Adverse effects
    • GI symptoms
  • Drug-to-drug interactions
    • Digoxin, oral anticoagulants, theophylline, and corticosteroids

Lincosamides

  • Similar to macrolides but more toxic
  • Action
    • Similar to macrolides
  • Indications
    • Severe infections
  • Pharmacokinetics
    • Well absorbed from the GI tract or IM
    • Metabolized in the liver and excreted in the urine and feces
  • Contraindications
    • Hepatic or renal impairment
  • Adverse effects
    • GI reactions

Monobactams

  • Unique structure with little cross-resistance
  • Action
    • Disrupts bacteria cell wall synthesis, which promotes the leakage of cellular content and cell death
  • Indications
    • Treatment of infections caused by susceptible bacteria; UTI, skin, intra-abdominal, and gynecologic infections
  • Pharmacokinetics
    • Well absorbed from the IM injection
    • Excreted unchanged in the urine
  • Contraindications
    • Allergy
  • Adverse effects
    • GI and hepatic enzyme elevation

Penicillins

  • First antibiotics introduced for clinical use
  • Action
    • Inhibit synthesis of the cell wall in susceptible bacteria, causing cell death
  • Indications
    • Treatment of infections caused by streptococcal, pneumococcal, staphylococcal, and other susceptible bacteria
  • Pharmacokinetics
    • Well absorbed from the GI tract
    • Excreted unchanged in the urine
  • Contraindications
    • Allergy
    • Caution in patients with renal disease
  • Adverse effects
    • GI effects
  • Drug-to-drug interactions
    • Tetracyclines and aminoglycosides

Sulfonamides

  • Drugs that inhibit folic acid synthesis
  • Action
    • Interfere with the cell-wall–building ability of dividing bacteria
  • Indications
    • Treatment of infections caused by gram-negative and gram positive-bacteria
  • Pharmacokinetics
    • Well absorbed from the GI tract
    • Metabolized in the liver and excreted in the urine
  • Contraindications
    • Allergy and pregnancy
  • Adverse effects
    • GI symptoms and renal effects related to the filtration of the drug
  • Drug-to-drug interactions
    • Cross sensitivity with thiazide diuretics
    • Sulfonylureas

Tetracyclines

  • Developed as semisynthetic antibiotics based on the structure of a common soil mold
  • Action
    • Inhibit protein synthesis in susceptible bacteria, preventing cell replication
  • Indications
    • Treatment of various infections caused by susceptible strains of bacteria and acne, and when penicillin is contraindicated for eradication of susceptible organisms
  • Pharmacokinetics
    • Adequately absorbed from the GI tract
    • Concentrated in the liver and excreted unchanged in the urine
  • Contraindications
    • Allergy, pregnancy, and lactation
  • Adverse effects
    • GI, skeletal: damage to bones and teeth
  • Drug-to-drug interactions
    • Penicillin G, oral contraceptive therapy, methoxyflurane, and digoxin

Antimycobacterials

  • Contain pathogens causing tuberculosis and leprosy
  • Action
    • Act on the DNA of the bacteria, leading to lack of growth and eventual bacterial death
  • Indication
    • Treatment of acid-fast bacteria
  • Pharmacokinetics
    • Well absorbed from the GI tract
    • Metabolized in the liver and excreted in the urine
  • Contraindications
    • Allergy and renal or hepatic failure
  • Adverse effects
    • CNS effects and GI irritation
  • Drug-to-drug interactions
    • Rifampin and INH can cause liver toxicity

Antibiotic Use Across the Lifespan

  • Pediatric population
  • Adult population
  • Geriatric population

Comparison of Prototype Antibiotics

Drug/ Classification Indication Action Route Onset Peak Pharmacokinetics Adverse Effects
Gentamicin/ Aminoglycosides Treatment of serious infections caused by susceptible bacteria Inhibits protein synthesis in susceptible strains of gram negative bacteria IM Rapid 30-90 min T½  – 2-3 h Sinusitis, dizziness, rash, fever, risk of nephrotoxicity
IV Metabolized in the liver,
excreted in the urine
Cefaclor/ Cephalosporins Treatment of respiratory, dermatological, urinary tract, and middle ear infections Inhibits synthesis of bacteria cell wall Oral 30-60 min 8-10 h T ½ 30-60 min Nausea, vomiting, diarrhea, rash, superinfections, bone marrow suppression, risk for pseudomembranous colitis
Excreted unchanged in the urine
Ciprofloxacin/ Fluoroquinolones Treatment of respiratory, dermatological, urinary tract, ear, eye, bone, and joint infections Interferes with DNA replication in susceptible gram negative bacteria Oral Varies 4-5 h T ½  – 3.5-4 h Headache, dizziness, hypotension, nausea, vomiting, diarrhea, fever, and rash
IV 10 min 4-5 h Metabolized in the liver,
excreted in bile and urine
Erythromycin/ Macrolides Treatment of respiratory, dermatological, urinary tract, and GI infections Binds to cell membrane causing change in protein function and cell death Oral 1-2 h 1-4 h T ½ – 3-5 h Abdominal cramping, vomiting, diarrhea, rash, superinfections, liver toxicity, potential for hearing loss
IV Rapid 1h Metabolized in the liver, CONTINUED ON NEXT SLIDE
excreted in bile and urine
Treatment of serious infections caused by susceptible strains of bacteria Inhibits protein synthesis in susceptible bacteria Oral Varies 1-2 h T ½ – 2-3 hours Nausea, vomiting, diarrhea, pseudomembranous colitis, bone marrow suppression, hypotension, cardiac arrest
IV Immed. Min Metabolized in the liver, excreted in bile and urine
IM 20-30 min 1-3 h
Aztreonam/ Treatment of lower respiratory, dermatological, urinary tract, intra-abdominal, and GYN infections Interferes with bacterial cell wall synthesis IM Varies 60-90 min T ½ – 1.5-2 h Nausea, vomiting, diarrhea, rash, superinfections, anaphylaxis, local discomfort at injection site
Monobactams IV Immed. 30 min Excreted in unchanged urine
Amoxicillin/ Treatment of infections caused by susceptible strains of bacteria Inhibits synthesis of the cell wall, causing cell death Oral Varies 1 h T ½  – 1-1.4 h Nausea, vomiting, diarrhea, glossitis, stomatitis, bone marrow suppression, rash, fever, lethargy
Penicillins Excreted unchanged in urine
Sulfasalazine/ Treatment of rheumatoid arthritis, arthritis, and ulcerative colitis Clindamycin/ Oral Varies 1.5-6 h T ½ – 5-10 h Nausea, vomiting, hepatocellular necrosis, hematuria, Stevens-Johnson syndrome, rash, photophobia, fever
Sulfonamides Lincosamides 6-24 h – metab. Metabolized in the liver, excreted in urine
Tetracycline/ Treatment of various infections caused by susceptible bacteria Inhibits protein synthesis in susceptible bacteria Oral Varies 2-4 h T ½ – 6-12 h Nausea, vomiting, diarrhea, discoloration of teeth, bone marrow suppression, photosensitivity
Tetracyclines Excreted unchanged in urine
Isoniazid/ Treatment of tuberculosis Interferes with lipid and nucleic acid synthesis in actively growing tubercle bacilli Oral Varies 1-2 h T ½  – 1-4 h Peripheral neuropathies, nausea, vomiting, hepatitis, bone marrow suppression, fever, gynecomatia, lupus syndrome
Antimycobacterials Metabolized in the liver, excreted in urine

Nursing Considerations—Aminoglycosides

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations—Cephalosporins

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations—Fluoroquinolones

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations— Macrolides & Lincosamides

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations—Monobactam

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations—Penicillins

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations—Sulfonamides

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations—Tetracyclines

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations—Antimycobacterials

  • Assessment and history
  • Nursing diagnosis
  • Implementation
  • Evaluation
Categories
Chemotherapeutic Agents Nursing Pharmacology

Anti-infective Agents

Anti-infective Agents

Drug Therapy Across the Lifespan

Drug Therapy Across the Lifespan
Drug Therapy Across the Lifespan

Development of Anti-infective Therapy

  • 1920s
    • Paul Ehrlich worked on developing a synthetic chemical effective against infection-causing cells only
    • Scientists discovered penicillin in a mold sample
  • 1935
    • The sulfonamides were introduced

Mechanisms of Action

  • Interfere with biosynthesis of the bacterial cell wall
  • Prevent the cells of the invading organism from using substances essential to their growth and development
  • Interfere with steps involved in protein synthesis
  • Interfere with DNA synthesis
  • Alter the permeability of the cell membrane to allow essential cellular components to leak out

Mechanism of Anti-infective Agents

Mechanism of Anti infective Agents
Mechanism of Anti infective Agents

Anti-infective Activity

  • Anti-infectives vary in their effectiveness against invading organisms
  • Some are selective: they are effective only for a small number of organisms
  • Bactericidal: kill the cell
  • Bacteriostatic: prevent reproduction of the cell

Narrow Spectrum vs Broad Spectrum

  • Narrow spectrum of activity
    • Effective against only a few microorganisms with a very specific metabolic pathway or enzyme
  • Broad spectrum of activity
    • Useful in treating a wide variety of infections

Human Immune Response

  • Goal of anti-infective therapy is reduction of the population of the invading organism
  • Drugs that eliminate all traces of any invading pathogen might be toxic to the host as well
  • Immune response is a complex process involving chemical mediators, leukocytes, lymphocytes, antibodies, and locally released enzymes and chemicals

Problems With Treating Infections in Immunosuppressed Patients

  • Anti-infective drugs cannot totally eliminate the pathogen without causing severe toxicity in the host
  • These patients do not have the immune response in place to deal with even a few invading organisms

Resistance

  • Anti-infectives act on a specific enzyme system or biological process; many microorganisms that do not act on a specific system are not affected by the particular drug
  • This is considered natural or intrinsic resistance to that drug

Acquired Resistance

  • Microorganisms that were once sensitive to the particular drug have begun to develop acquired resistance
  • This results in serious clinical problems

Ways Resistance Develops

  • Producing an enzyme that deactivates the antimicrobial drug
  • Changing cellular permeability to prevent the drug from entering the cell
  • Altering transport systems to exclude the drug from active transport into the cell
  • Altering binding sites on the membranes or ribosomes, which then no longer accept the drug
  • Producing a chemical that acts as an antagonist to the drug

Preventing Resistance

  • Limit the use of antimicrobial agents to the treatment of specific pathogens sensitive to the drug being used
  • Make sure doses are high enough, and the duration of drug therapy long enough
  • Be cautious about the indiscriminate use of anti-infectives

Identification of the Pathogen

  • Identification of the infecting pathogen is done by culture
  • A culture of a tissue sample from the infected area is done
    • A swab of infected tissue is allowed to grow on an agar plate
    • Staining techniques and microscopic examination identify the bacterium
  • Stool can be examined for ova and parasites

Sensitivity of Pathogen

  • Shows which drugs are capable of controlling the particular microorganism
  • Important to be done for microorganisms that have known resistant strains
  • Along with a culture, identifies the pathogen and appropriate drug for treatment

Factors Affecting Prescribing Anti-infective Agents

  • Identification of the correct pathogen
  • Selection of the right drug
    • One that causes the least complications for that particular patient
    • One that is most effective against the pathogen involved

Combination Therapy

  • Use of a smaller dosage of each drug
  • Some drugs are synergistic
  • In infections caused by more than one organism, each pathogen may react to a different anti-infective agent
  • Sometimes, the combined effects of the different drugs delay the emergence of resistant strains

Adverse Reactions to Anti-infective Therapy

  • Kidney damage
  • Gastrointestinal (GI) tract toxicity
  • Neurotoxicity
  • Hypersensitivity reactions
  • Superinfections

Prophylaxis of Anti-infective Agents

  • People traveling to areas where malaria is endemic
  • Patients who are undergoing gastrointestinal or genitourinary surgery
  • Patients with known cardiac valve disease, valve replacements, and other conditions requiring invasive procedures
Categories
Chemotherapeutic Agents Nursing Pharmacology

Introduction to Cell Physiology

Introduction to Cell Physiology

Chemotherapeutic Agents

  • Alter cellular function or disrupt cellular integrity, causing cell death
  • Prevent cellular reproduction, eventually leading to cell death

Chemotherapeutic Drugs

  • Destroy organisms that invade the body
    • Bacteria, viruses, parasites, protozoa, fungi
  • Destroy abnormal cells within the body
    • Neoplasms and cancers

Parts of a Human Cell

  • Nucleus
  • Cell membrane
  • Cytoplasm

Structure of a Cell

Stucture of a Cell
Stucture of a Cell

Cell Nucleus

  • Contains genetic material
    • Necessary for cell reproduction
    • Regulates cellular production of proteins
  • Each cell is “programmed” by the genes for the production of specific proteins
    • Allows the cell to carry out its function
    • Maintains cell homeostasis or stability
    • Promotes cell division

Cell Membrane

  • Surrounds the cell
  • Separates the intracellular fluid from the extracellular fluid
  • Essential for cellular integrity

Structure of a Lipid Cell Membrane

Structure of a Lipid Cell Membrane
Structure of a Lipid Cell Membrane

Organelles of the Cytoplasm

  • Mitochondria
  • Endoplasmic reticulum
  • Free ribosomes
  • Golgi apparatus
  • Lysosomes

Components of Cell Membrane

  • Cell membrane is made up of lipids and proteins
  • Several lipids make up the cell membrane
    • Phospholipids
    • Glycolipids
    • Cholesterol
  • Lipid layer provides a barrier for the cell and maintains homeostasis of the cell

Receptor Sites

  • Found on the cell membrane
  • Specific receptor sites allow interaction with various chemicals

Identifying Markers

  • Surface antigens
  • Important in the role of cellular immunity
  • Histocompatibility proteins allow for self-identification
  • The body’s immune system recognizes these proteins and acts to protect self-cells and to destroy non–self-cells

Channels

  • Channels or pores allow for the passage of substances into and out of the cell
  • Some drugs are designed to affect certain channels within the cell

Cell Properties

  • Endocytosis
    • Involves incorporation of material into the cell
    • Pinocytosis and phagocytosis occur
  • Exocytosis
    • Allows a cell to move a substance to the cell membrane and secrete the substance outside the cell
    • Hormones, neurotransmitters, and enzymes are excreted into the body by this process

Homeostasis of the Cell

  • Passive transport
    • Happens without the expenditure of energy and can occur across any semipermeable membrane
    • Occurs by diffusion, osmosis, and facilitated diffusion
  • Active transport
    • Energy-requiring process
    • Movement of particular substances against a concentration gradient
    • Important in maintaining cell homeostasis

Passive Transport

  • Diffusion
    • Does not require energy
    • The movement of solutes from a region of high concentration to a region of lower concentration across a concentration gradient
  • Osmosis
    • Does not require energy
    • Movement of water from an area low in solutes to an area high in solutes

Phases of the Cell Cycle

  • G0 phase
    • Resting phase
  • G1 phase
    • Gathering phase
  • S phase
    • Synthesizing phase
  • G2 phase
    • Last substances needed for division are collected and produced
  • M phase
    • Actual cell division occurs, producing two identical daughter cells

Cell Cycle

Cell Cycle
Cell Cycle

Cell Physiology

  • May alter the cell membrane, causing the cell to rupture and die
  • May deprive the cell of certain nutrients, altering the proteins that the cell produces and interfering with normal cell functioning and cell division
  • May affect the normal cells of patients to some extent