Introduction to Nursing Pharmacology Nursing Pharmacology

Toxic Effects of Drugs

Toxic Effects of Drugs

Adverse Drug Reaction

  • Definition
    • Adverse effects are undesired effects that may be unpleasant or even dangerous
  • Reasons adverse drug reactions occur:
    • The drug may have other effects on the body besides the therapeutic effect
    • The patient is sensitive to the drug given
    • The drug’s action on the body causes other responses
    • The patient is taking too much or too little of the drug

Types of Adverse Reactions

  • Primary actions
    • Overdose: extension of the desired effect
  • Secondary actions
    • Undesired effects produced in addition to the pharmacologic effect
  • Hypersensitivity reactions
    • Excessive response to the primary or secondary effect of the drug

Types of Drug Allergies

  • Anaphylactic reaction
  • Cytotoxic reaction
  • Serum sickness reaction
  • Delayed allergic reaction

Variety of Adverse Effects Associated With Drug Use

Types of Drugs Allergies
Types of Drugs Allergies

Drug-Induced Tissue & Organ Damage

Drug-Induced Tissue and Organ Damage
Drug-Induced Tissue and Organ Damage

Dermatologic Reactions

  • Rash/hives
    • Assessment
      • Abnormalities in the skin, red areas, blisters
    • Interventions
      • May need to discontinue the medication
  • Stomatitis
    • Assessment
      • Inflammation of the mucous membranes
    • Interventions
      • Frequent mouth care

Drug-Induced Tissue and Organ Damage

  • Superinfections: destruction of the body’s normal flora
    • Assessment
      • Fever, diarrhea, and vaginal discharge
    • Interventions
      • Supportive care (mouth/skin care), give antifungal medications, stop drug responsible for the infection
  • Blood dyscrasia: bone marrow suppression
    • Assessment
      • Fever, chills, and weakness
    • Interventions
      • Monitor blood counts and protective isolation


  • Liver
    • Assessment
      • Fever, nausea, jaundice, change in color of urine or stool, and elevated liver enzymes
    • Interventions
      • Discontinue medication
  • Kidney
    • Assessment
      • Change in urinary pattern or elevated BUN and creatinine
    • Interventions
      • Notify physician, stop medication, or decrease dosage


  • Poisoning occurs when an overdose of a drug damages multiple body systems
  • Damage to multiple systems can lead to a fatal reaction

Altered Glucose Metabolism

  • Hypoglycemia
    • Assessment finding: low serum blood glucose level
    • Intervention: restore glucose to the body (D50)
  • Hyperglycemia
    • Assessment finding: high serum glucose level
    • Intervention: administer medications to decrease glucose level (insulin)

Electrolyte Imbalances

  • Hypokalemia
    • Assessment finding: decrease in serum potassium level
    • Interventions: replace serum potassium (IV or oral supplement) and monitor serum level of potassium
  • Hyperkalemia
    • Assessment finding: increase in serum potassium level
    • Interventions: decrease the serum potassium concentration (using sodium polystyrene sulfonate), monitor serum level of potassium, and monitor cardiac rhythm

Sensory Effects

  • Ocular toxicity
    • Assessment finding: visual changes
    • Interventions: monitor for visual changes when giving medication known to cause ocular damage; discontinue medication after notifying physician
  • Auditory damage
    • Assessment finding: damage to the eighth cranial nerve
    • Interventions: monitor for hearing loss; discontinue medication after notifying physician

Neurologic Effects

  • General central nervous system (CNS) effects
    • Assessment: altered level of consciousness
    • Intervention: prevent injury
  • Atropine-like (anticholinergic) effects
    • Assessment: dry mouth, urinary retention, and blurred vision
    • Interventions: sugarless lozenges to keep mouth moist; advise the patient to void before administration of the medication
  • Parkinson-like syndrome
    • Assessment: muscle tremors and changes in gait
    • Intervention: discontinue medication
  • Neuroleptic malignant syndrome
    • Assessment: extrapyramidal symptoms
    • Intervention: discontinue medication


  • Drugs may harm the developing fetus or embryo
  • Prevent teratogenicity through teaching
    • Advise pregnant women that any medication may adversely affect the baby
    • Weigh the actual benefits against the potential risks
    • Advise pregnant women that they should not take medications without checking with their health care provider first