Tag: chemical mediators

Anti-inflammatory Agents

Inflammatory Response

Protects the body from injury and pathogens
Uses chemical mediators to produce the reaction that helps destroy pathogens and promote healing

Anti-inflammatory Agents

Block or alter the chemical reactions associated with the inflammatory response

Types of Anti-inflammatory Agents

Corticosteroids: used systemically to block the inflammatory and immune systems
Antihistamines: block the release of histamine in the initiation of the inflammatory response

Salicylates

Can block the inflammatory response
Have antipyretic (fever-blocking) properties
Have analgesic (pain-blocking) properties

NSAIDs

Provide strong anti-inflammatory and analgesic effects
Sold over the counter, which may lead to abuse

Common Salicylates

Aspirin (Bayer,etc.): treats inflammatory conditions
Balsalazide (Colazal): new drug that treats ulcerative colitis
Choline magnesium trisalicylate (Trilisate): treats mild pain and fevers as well as arthritis
Choline salicylate (Arthropan): treats mild pain and fevers as well as arthritis
Mesalamine (Pentasa, etc.): treats inflammation of the large intestine
Olsalazine (Dipentum): converted to mesalamine in the colon; has the same direct anti-inflammatory effects
Salsalate (Argesic, etc.): treats pain, fever, and inflammation
Sodium thiosalicylate (Rexolate): treats episodes of acute gout and muscular pain as well as rheumatic fever

Salicylates

Action/indication
- Inhibit synthesis of prostaglandin; used to treat mild to moderate pain and fever
Pharmacokinetics
- Absorbed from the stomach, peak in 5 to 30 min., metabolized in the liver, and excreted in the urine
Contraindications
- Known allergy, bleeding abnormalities, and impaired renal function
Drug-to-drug interactions
- Interact with other drugs by interfering with absorption

Salicylates—Adverse Effects

GI irritation
- Nausea, dyspepsia, and heartburn
Clotting system
- Blood loss and bleeding abnormalities
Eighth cranial nerve stimulation
Salicylism
- Ringing in the ears
- Acidosis
- Nausea, vomiting, and diarrhea
- Mental confusion and lassitude

Types of NSAIDs

Propionic acids
- Fenoprofen
- Ibuprofen
Acetic acids
- Diclofenac
- Etodolac
Fenamates
- Mefenamic acid
Cyclooxygenase-2 inhibitors
- Celecoxib

NSAIDs Indications

Relief of the signs and symptoms of rheumatoid arthritis and osteoarthritis
Relief of mild to moderate pain
Treatment of primary dysmenorrhea
Fever reduction

Contraindications to NSAIDs

Presence of allergy to any NSAID or salicylate
Cardiovascular dysfunction or hypertension
Peptic ulcer or known GI bleeding
Pregnancy and lactation
Caution with renal or hepatic dysfunction

Other Anti-inflammatory Agents

Acetaminophen (Tylenol)
Gold compounds
Antiarthritic drugs

Acetaminophen

Action/indications
- Acts directly on the thermoregulatory cells of the hypothalamus
- Mechanism of action related to analgesic effects is not certain
- Used to treat pain and fever
  - Treatment of pain and fever associated with a variety of conditions, including influenza
  - Prophylaxis of children receiving diphtheria–pertussis–tetanus (DPT) immunizations
  - Relief of musculoskeletal pain associated with arthritis
Pharmacokinetics
- Absorbed from the GI tract
- Peaks in ½ to 2 hours
- Metabolized in the liver
- Excreted in the urine
- T½ is about 2 hours
Contraindications
- Known allergy
- Use with caution in pregnancy and lactation
Adverse reactions
- - Headache, hemolytic anemia, renal dysfunction, skin rash, fever, and hepatotoxicity
- Drug-to-drug interactions
  - Oral anticoagulants increase bleeding

Gold Compounds

Action
- Absorbed by macrophages, which results in inhibition of phagocytosis
Indication
- Tissue destruction is decreased
Pharmacokinetics
- Absorption varies based on the site of administration
- Widely distributed throughout the body
Contraindications
- - Known allergy
  - Diabetes, CHF, and renal or hepatic impairment
- Adverse reactions
  - Stomatitis, glossitis, gingivitis, bone marrow depression, and dermatitis
- Drug-to-drug interactions
  - Penicillamine, antimalarials, cytotoxic drugs, and immunosuppressive agents

Other Antiarthritis Drugs

Etanercept (Enbrel)
Leflunomide (Arava)
Penicillamine (Depen)
Hyaluronidase derivative (Synvisc)
Sodium hyaluronate (Hyalgan)
Anakinra (Kineret)

Use of Anti-inflammatory Agents Across the Lifespan

Prototype Salicylates

Prototype NSAIDs

Prototype Acetaminophen

Prototype Gold Compound

Nursing Considerations for Salicylates

Assessment (history and physical exam)
Nursing diagnosis
Implementation
Evaluation

Nursing Considerations for NSAIDs

Assessment (history and physical exam)
Nursing diagnosis
Implementation
Evaluation

Drugs Acting on the Immune System Nursing

Introduction to the Immune Response and Inflammation

Post author By Mark Anthony Sabandal
Post date March 10, 2011
No Comments on Introduction to the Immune Response and Inflammation

Introduction to the Immune Response and Inflammation

Body’s Defenses

Barrier defenses
Cellular defenses
Inflammatory response
Immune response

Barrier Defenses

Skin
- Protects the internal tissues and organs of the body
Mucous membrane
- Lines the areas of the body that are exposed to external influences but do not have skin protection
Gastric acid
- Secreted by the stomach in response to many stimuli
Major histocompatibility complex
- Distinguishes between self-cells and foreign cells

Types of Cellular Defenses

Mononuclear phagocyte system (MPS)
- Composed of:
  - Thymus gland
  - Lymphatic tissue
  - Leukocytes
  - Lymphocytes
  - Numerous chemical mediators

Types of White Blood Cells—Leukocytes—Produced by the Body

Types of Leukocytes

The Inflammatory Response Hageman Factor (Factor XII)

A chemical in the plasma activated by cell injury
Responsible for activating three systems in the body
- The kinin system
- The clotting cascade: starts blood clotting
- The plasminogen system: starts the dissolution of blood clots

The Role of Bradykinin

Causes local vasodilation
Stimulates nerve endings to cause pain
Causes the release of arachidonic acid
This release of arachidonic acid causes the release of autocoids

Types of Autocoids Released

Prostaglandins
- Some augment the inflammatory reaction and some block it
Leukotrienes
- Some can cause vasodilation and increased capillary permeability and some can block the reactions
Thromboxanes
- Cause local vasoconstriction and facilitate platelet aggregation and blood coagulation

Clinical Presentation

Calor (heat)
- Caused by increased blood flow
Tumor (swelling)
- Caused by fluid that leaks into the tissues
Rubor (redness)
- Caused by the increase in blood flow due to vasodilation
Dolor (pain)
- Caused by the activation of pain fibers

Inflammatory Response

Immune Response

Specific invasions stimulate specific responses through the immune system
- Lymphocytes produced in the bone marrow can develop into T lymphocytes or B lymphocytes
- Other identified lymphocytes include natural killer cells and lymphokine-activated killer cells
  - These cells are aggressive against neoplastic or cancer cells and promote rapid cellular death

Types of T Cells

Effector or cytotoxic T cells
Helper T cells
Suppressor T cells

Function of T Cells

Effector or cytotoxic T cells
- Found throughout the body
- Aggressive against non-self cells
- Can directly destroy foreign cells or mark cell so other cells can destroy them
Helper T cells
- Stimulate the activity of B cells and effector T cells
Suppressor T cells
- Monitor the chemical activity in the body
- Act to suppress B-cell and T-cell activity when the foreign antigen is under control

Cell-Mediated Response

The Role of the B Cell

Programmed to identify specific proteins or antigens
Involved in humoral immunity
Produces antibodies or immunoglobulins

Humoral Immune Response

Response to the Varicella Virus

Other Mediators in the Immune Response

•nterferons
- Prevent viral replication and suppress malignant cell replication and tumor growth
Interleukins
- Chemicals secreted by active leukocytes to influence other leukocytes
Tumor necrosis factor (TNF)
- Chemical released by macrophages; inhibits tumor growth and can cause tumor regression

Conditions That Cause Problems Involving the Immune System

Neoplasm
Viral invasion
Autoimmune disease
Transplant rejection

Theories of Autoimmune Disease

Result of response to a cell that was invaded by a virus, leading to antibody production to similar cells
In a state of immunosuppression, the suppressor T cells do not suppress autoantibody production
There is a genetic predisposition to develop autoantibodies

Chemotherapeutic Agents Nursing Pharmacology

Anti-infective Agents

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

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