PSA Prescribing in Special Populations 3 — Questions and Answers
Question 1: A pregnant woman in her first trimester requires antibiotic therapy for a urinary tract infection. Which antibiotic is most appropriate?
- Nitrofurantoin at 32 weeks gestation or later
- Trimethoprim in the first trimester
- Cefalexin throughout pregnancy (Correct answer)
- Tetracycline
Correct answer: Cefalexin throughout pregnancy
Cefalexin, a first-generation cephalosporin, is considered safe throughout pregnancy and is a first-line option for UTI treatment in pregnant women.
Question 2: A breastfeeding mother needs analgesia following a Caesarean section. Which analgesic should be used with the greatest caution?
- Paracetamol
- Ibuprofen
- Codeine (Correct answer)
- Diclofenac
Correct answer: Codeine
Codeine is converted to morphine by CYP2D6; in ultra-rapid metabolizers, excessive morphine passes into breast milk and can cause neonatal respiratory depression.
Question 3: Which antiepileptic drug carries the highest risk of neural tube defects when taken during the first trimester of pregnancy?
- Lamotrigine
- Levetiracetam
- Sodium valproate (Correct answer)
- Carbamazepine
Correct answer: Sodium valproate
Sodium valproate is associated with the highest risk of neural tube defects (approximately 3-4%) and major congenital malformations among antiepileptic drugs.
Question 4: A woman with a mechanical heart valve is planning a pregnancy and is currently on warfarin. What is the most appropriate management for the first trimester?
- Continue warfarin unchanged throughout pregnancy
- Switch to low molecular weight heparin during the first trimester (Correct answer)
- Stop all anticoagulation during the first trimester
- Switch to aspirin for the duration of pregnancy
Correct answer: Switch to low molecular weight heparin during the first trimester
Warfarin is teratogenic during the first trimester; low molecular weight heparin does not cross the placenta and is preferred during this period.
Question 5: Which class of antihypertensive drug is contraindicated throughout pregnancy?
- Beta-blockers
- Methyldopa
- ACE inhibitors (Correct answer)
- Calcium channel blockers
Correct answer: ACE inhibitors
ACE inhibitors are contraindicated in pregnancy due to the risk of fetal renal dysgenesis, oligohydramnios, skull hypoplasia, and neonatal renal failure.
Question 6: A woman at 34 weeks gestation develops severe pre-eclampsia with a BP of 175/112 mmHg. What is the first-line drug treatment?
- Oral ramipril
- IV labetalol (Correct answer)
- Oral furosemide
- IV hydralazine as first choice over labetalol
Correct answer: IV labetalol
IV labetalol is the first-line treatment for severe hypertension in pre-eclampsia as it is safe in pregnancy, rapid-acting, and well-evidenced.
Question 7: A breastfeeding mother is diagnosed with postnatal depression and requires an antidepressant. Which drug has the most safety data supporting use during breastfeeding?
- Sertraline (Correct answer)
- Venlafaxine
- Mirtazapine
- Fluoxetine
Correct answer: Sertraline
Sertraline has the most published safety data in breastfeeding, with consistently low levels detected in breast milk and no adverse effects reported in exposed infants.
PSA Prescribing in Special Populations 3
A pregnant woman in her first trimester requires antibiotic therapy for a urinary tract infection.
Which antibiotic is most appropriate?