Screen for penicillin allergy, EBV-associated rash risk, and renal function before starting ampicillin.
Absolute contraindications include immediate hypersensitivity to penicillins. Relative cautions include infectious mononucleosis, concomitant allopurinol (rash risk), renal impairment (for IV dosing), and history of severe C. difficile infection.
Documented anaphylaxis, angioedema, or severe cutaneous adverse reaction to ampicillin or any penicillin-class antibiotic
Known hypersensitivity to formulation excipients (e.g., sodium citrate in suspension)
Active Epstein-Barr virus infection or acute lymphocytic leukemia—high incidence of morbilliform rash
History of Clostridioides difficile infection (monitor for recurrence)
Severe renal impairment or hemodialysis (adjust dosing interval to prevent accumulation)
Patients with cephalosporin or carbapenem allergy—assess severity before prescribing
Use with allopurinol increases rash risk; counsel families on monitoring
Ampicillin is widely used for intrapartum prophylaxis; generally compatible with breastfeeding. Monitor infants for diarrhea or candidiasis.