Pregnancy and antibiotics

For UTI, use nitrofurantoin prescribe as 50 mg QID for 7 days.¹ However, avoid in patients who are ≥ 36 weeks gestation (risk of neonatal hemolysis) or those with creatinine clearance < 60 mL/min.¹ Alternatives are trimethoprim (after the first 3 months) and amoxicillin (both only if directed by culture results) or cefalexin; 500 mg BD for 7 days.¹

Asymptomatic bacteriuria (growth of greater than 105 cfu/mL) or Group B strep on urine culture can be treated with amoxil or cefalexin and then give penicillin prophylactically at time of delivery.²

For bacterial vaginosis: metronidazole can be used but not ornidazole.¹

For pertussis, azithromycin is the preferred macrolide.¹

Antibiotics to avoid include amoxycillin with clavulanate, quinolones (norfloxacin and ciprofloxacin), tetracyclines (including doxycycline) trimethoprim in first trimester and co-trimoxazole.¹