Pharmacology: Adverse Drug Reactions and Toxicity

Flashcards generated from Chapter 3 pharmacology transcript covering adverse drug reactions, hypersensitivity, organ toxicities, electrolyte imbalances, and safety protocols.

How are adverse drug reactions defined in Chapter 3?

Undesired effects of medications that may be unpleasant and/or dangerous.

What is blood dyscrasia?

Bone marrow suppression caused by drug effects on rapidly multiplying cells, resulting in lower-than-normal blood cell levels.

What spectrum of skin manifestations defines dermatologic reactions?

Skin reactions ranging from a simple rash to potentially fatal exfoliative dermatitis.

What basic requirement must be met for a patient to develop a true drug allergy or hypersensitivity?

The patient must have prior exposure to the drug or a cross-reactive drug in the same class to form antibodies.

What defines drug poisoning?

An overdose of a drug that causes damage to multiple body systems and carries the potential for fatal reactions.

What is stomatitis and what complications can it cause?

Inflammation of the mucous membranes related to drug effects, which can lead to alterations in nutrition and dental problems.

How do superinfections develop during drug therapy?

They are caused by the destruction of normal flora bacteria by drugs such as antibiotics, allowing other organisms to grow out of control.

What is the primary function of the FDA MedWatch program?

To serve as a safety information and adverse event reporting system for FDA-regulated products.

Which specific reporting system is designated for adverse events occurring after vaccine administration?

Vaccine Adverse Event Reporting System (VAERS).

What is a primary action of a drug?

An extension of a drug's desired therapeutic effect resulting from therapeutic or supratherapeutic drug levels.

How does renal impairment contribute to exaggerated adverse drug effects?

It impairs drug excretion, causing drug accumulation and toxic effects.

What is a secondary action of a drug?

Adverse effects that occur in addition to the desired pharmacologic effect and are not directly part of the primary therapeutic goal.

Which immune components and mediators are involved in a Type I Immediate Hypersensitivity reaction?

Antigen reaction with type 2 helper T cells, leading to IgE production, mast cell sensitization, and release of histamine.

What are the priority emergency interventions when a patient develops anaphylaxis?

Withdraw the allergen, administer epinephrine, and maintain airway and blood pressure.

What timeframe and symptoms are typical for Type III Immune Complex-Mediated Disorders (Serum Sickness)?

Manifests 7 to 14 days (or around 8 days) after exposure with generalized edema, itchy rash, high fever, swollen lymph nodes, and painful joints (arthralgias).

Which immune cells directly mediate Type IV hypersensitivity reactions?

T cells activated by antigen causing cell death or cytokine release.

Which severe skin reaction is associated with sulfamethoxazole and trimethoprim (Bactrim)?

Stevens-Johnson syndrome (erythema multiforme exudativum).

Why are bone marrow cells highly susceptible to cytotoxic drug effects?

Because they are rapidly turning over and multiply frequently.

Which diagnostic laboratory tests are monitored to detect drug-induced hepatotoxicity?

Aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin, and PTT.

Which laboratory values serve as the primary indicators of drug-induced nephrotoxicity?

Elevated Blood Urea Nitrogen (BUN) and elevated serum creatinine.

What assessment findings characterize atropine-like (anticholinergic) adverse effects?

Dry mouth, urinary retention, constipation, blurred vision, photophobia, headache, dilated pupils, dry skin, and decreased sweating.

What are extrapyramidal symptoms (EPS) and what drug class commonly produces them?

Involuntary motor movements (rigidity, akathisia, dystonia, tremors, drooling, shuffling gait) caused by antipsychotic and neuroleptic drugs that block dopamine pathways.

What clinical features define Neuroleptic Malignant Syndrome (NMS)?

Fever, severe muscle rigidity, autonomic instability, and altered mental status.

What is ototoxicity and which medication classes frequently cause it?

Auditory nerve damage and inner ear toxicity causing tinnitus, hearing loss, and vertigo; commonly caused by aminoglycosides (e.g., gentamicin) and loop diuretics (e.g., furosemide).

What serum potassium level threshold defines hypokalemia?

A serum potassium level lower than 3.5 mEq/L.

What electrocardiogram (ECG) changes are classic for hyperkalemia?

Tall, peaked T waves and widened QRS complexes.

What serum blood glucose level defines hypoglycemia, and what is the immediate intervention for a conscious patient?

Serum glucose less than 70 mg/dL; immediate intervention is administering fast-acting oral carbohydrates.

What is teratogenicity and during which gestational period is the fetus at highest risk?

The ability of a drug or chemical agent to cause malformations or death in a developing fetus; highest risk occurs during the first trimester (organogenesis).

How can Red Man Syndrome be prevented during intravenous vancomycin administration?

By slowing the IV infusion rate to infuse over at least 60 minutes.

What severe soft tissue adverse effect requires monitoring in patients taking fluoroquinolone antibiotics?

Tendinitis and tendon rupture (especially of the Achilles tendon).

What condition should be suspected if a patient taking a daily statin reports severe, unexplained muscle pain and dark urine?

Rhabdomyolysis.