Pharmacology Flashcards

A patient is prescribed phenytoin for seizure control. Which adverse effect is specific to this drug?

Answer: Gingival hyperplasia (gum overgrowth)

Gingival hyperplasia (gum overgrowth) is a characteristic adverse effect of phenytoin, occurring in up to 50% of patients. Good oral hygiene reduces severity. Other phenytoin adverse effects include nystagmus, ataxia, diplopia, and teratogenicity (fetal hydantoin syndrome).

Which antibiotics are absolutely contraindicated in children under 8 years?

Answer: Tetracyclines

Tetracyclines bind to calcium in developing bones and teeth, causing permanent dental staining (brown-grey discoloration) and impaired bone growth when given to children under 8 years or during pregnancy. They are absolutely contraindicated in these populations.

What does 'half-life' mean in pharmacology?

Answer: The time required for the plasma concentration of a drug to decrease by 50%

Half-life (t½) is the time required for drug plasma concentration to fall by 50%. It determines dosing frequency (steady state reached at ~5 half-lives, drug essentially eliminated in ~5 half-lives). Drugs with long half-lives require less frequent dosing.

A nurse prepares to administer insulin. Which type of insulin is clear in appearance?

Answer: Regular (soluble) insulin and insulin analogues (lispro, aspart, glargine)

Regular (soluble) insulin and most insulin analogues (lispro, aspart, glargine, detemir) are clear solutions. NPH (Neutral Protamine Hagedorn) insulin appears cloudy/turbid due to the protamine suspension. Premixed insulins (70% NPH/30% regular) are cloudy.

What is the primary concern when administering IV aminophylline?

Answer: Cardiac arrhythmias and seizures from rapid administration

Aminophylline (theophylline) has a narrow therapeutic index. Rapid IV administration can cause severe cardiac arrhythmias (tachycardia, ventricular arrhythmias) and seizures due to CNS stimulation. It must be given as a slow infusion with cardiac monitoring and serum level monitoring.

Which medication is used to treat hypercalcemia caused by malignancy?

Answer: IV bisphosphonates (zoledronic acid, pamidronate)

Bisphosphonates are the cornerstone of malignancy-associated hypercalcemia treatment. They inhibit osteoclast activity, reducing calcium release from bone. IV administration provides rapid effect. Hydration with normal saline and furosemide are supportive measures.