SNLE Pharmacology 4 — Questions and Answers
Question 1: A patient is prescribed phenytoin for seizure control. Which adverse effect is specific to this drug?
- Gingival hyperplasia (gum overgrowth) (Correct answer)
- Renal calculi
- Pulmonary fibrosis
- Severe weight gain
Correct 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).
Question 2: Which antibiotics are absolutely contraindicated in children under 8 years?
- Tetracyclines (Correct answer)
- Penicillins
- Cephalosporins
- Macrolides
Correct 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.
Question 3: What does 'half-life' mean in pharmacology?
- The time required for the plasma concentration of a drug to decrease by 50% (Correct answer)
- The duration of drug action
- The time to reach peak plasma level
- The time for complete elimination
Correct 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.
Question 4: A nurse prepares to administer insulin. Which type of insulin is clear in appearance?
- Regular (soluble) insulin and insulin analogues (lispro, aspart, glargine) (Correct answer)
- NPH insulin
- All insulin types are clear
- Premixed insulin 70/30
Correct 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.
Question 5: What is the primary concern when administering IV aminophylline?
- Cardiac arrhythmias and seizures from rapid administration (Correct answer)
- Respiratory depression
- Severe hypoglycemia
- Renal failure
Correct 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.
Question 6: Which medication is used to treat hypercalcemia caused by malignancy?
- IV bisphosphonates (zoledronic acid, pamidronate) (Correct answer)
- Calcium gluconate IV
- Vitamin D supplements
- Furosemide alone
Correct 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.
SNLE Pharmacology 4
A patient is prescribed phenytoin for seizure control.
Which adverse effect is specific to this drug?