Tucker 3 Toxic Effects of Drugs Flashcards

Adverse effects

Undesired effects of a drug that may be unpleasant or dangerous and can occur because of off-target effects, patient sensitivity, or secondary drug reactions.

Primary action

Extension of the drug’s desired effect; for example, an anticoagulant causing excessive bleeding at a standard dose.

Secondary actions

Effects of a drug that are not related to its therapeutic effect and may be undesirable or unavoidable in some patients.

Drug allergy or hypersensitivity

Immune-mediated reaction to a drug, often involving antibodies; can be immediate or delayed and may include cross-allergies with related drugs.

Type I hypersensitivity (immediate)

IgE-mediated reaction that can cause hives, bronchospasm, and anaphylaxis; rapid removal of the allergen and epinephrine if anaphylaxis occurs.

Anaphylaxis

Severe, life-threatening systemic allergic reaction with airway compromise and shock; treated with epinephrine, airway support, and removal of the trigger.

Type II hypersensitivity (antibody-mediated)

IgG or IgM antibodies attack cell-surface antigens, causing destruction of those cells and possible organ dysfunction.

Type III hypersensitivity (immune complex–mediated)

Circulating antigen–antibody complexes deposit in tissues, causing inflammation; can present as serum sickness days to weeks after exposure.

Type IV hypersensitivity (cell-mediated)

T-cell–mediated delayed reaction causing inflammation and tissue damage (e.g., contact dermatitis) hours to days after exposure.

Stomatitis

Inflammation of mucous membranes in the mouth due to direct drug toxicity or deposition, leading to mouth pain and nutritional issues.

Dermatological reactions

Skin adverse reactions from drugs ranging from rash and hives to severe conditions like Stevens-Johnson syndrome.

Blood dyscrasia

Bone marrow suppression causing reduced blood cell counts (anemia, leukopenia, thrombocytopenia) and pancytopenia in severe cases.

Superinfections

New infections caused by destruction of normal flora by drugs (especially antibiotics), allowing pathogenic organisms to flourish.

Hepatotoxicity

Liver damage caused by drugs; often related to first-pass metabolism and toxic metabolites; monitored via liver function tests.

Nephrotoxicity

Kidney toxicity from drugs due to mechanisms like vasoconstriction, tubular damage, or obstruction; may require stopping the drug or dialysis.

Hypokalemia

Low serum potassium caused by certain drugs; can cause weakness, arrhythmias, and may require potassium replacement and monitoring.

Hyperkalemia

High serum potassium caused by drugs or cell breakdown; can cause weakness and arrhythmias; treated with measures to lower potassium (e.g., patiromer).

Ocular toxicity (oculotoxicity)

Drug-induced damage to the eyes or retina, potentially leading to vision impairment or blindness (e.g., chloroquine).

Auditory damage (ototoxicity)

Drug-induced hearing loss or tinnitus; associated with aminoglycosides and high-dose macrolides; monitor hearing function.

Extrapyramidal symptoms

Movement disorders resembling Parkinson’s disease caused by certain drugs (e.g., haloperidol); may require dose adjustment or anticholinergic therapy.

Neuroleptic malignant syndrome (NMS)

Life-threatening CNS reaction with high fever, rigidity, and autonomic instability; treated with cooling and dopaminergic agents; medical emergency.

Teratogenicity

Potential of a drug to cause fetal harm or birth defects; requires risk–benefit assessment in pregnancy and cautious use.

Poisoning (drug poisoning)

Overdose causing multi-system damage; requires emergency care and, when possible, specific antidotes or supportive measures.

Electrolyte imbalances

Drugs can alter electrolyte levels (notably potassium), causing hypo- or hyperkalemia with significant clinical effects.

General CNS effects

Drugs can affect the central nervous system, causing symptoms such as confusion, delirium, drowsiness, seizures, or headache.

Anticholinergic effects

Blockade of parasympathetic activity causing dry mouth, urinary retention, constipation, blurred vision, and other symptoms.

Extrapyramidal symptoms (repeated)

Dopamine-related movement disorders from certain drugs; include tremor, dystonia, akathisia, and rigidity.

Neuroleptic malignant syndrome (NMS) (repeated)

Severe reaction with hyperthermia and rigidity; emergency management with cooling and dopamine-activating therapy.

Teratogenicity (repeated)

Drug-induced fetal harm; careful assessment of benefits and risks during pregnancy.