1. The patient should inform the physician of any history of sensitivity to allergens, including previous hypersensitivity reactions to penicillins and cephalosporins.
2. The patient should discontinue ampicillin and contact the physician immediately if any side effect occurs.
3. Ampicillin should be taken with a full glass (8 oz) of water, one-half hour before or two hours after meals.
4. Diabetic patients should consult with the physician before changing diet or dosage of diabetes medication .
When administered concurrently, the following drugs may interact with ampicillin.
Allopurinol: Increased possibility of skin rash, particularly in hyperuricemic patients may occur.
Bacteriostatic Antibiotics: Chloramphenicol, erythromycins, sulfonamides, or tetracyclines may interfere with the bactericidal effect of penicillins. This has been demonstrated in view, however, the clinical significance of this interaction is not well documented.
Oral Contraceptives: May be less effective and increased breakthrough bleeding may occur.
Probenecid: May decrease renal tubular secretion of ampicillin resulting in increased blood levels and/or ampicillin toxicity.
Drug/Laboratory Test Interaction
After treatment with ampicillin, a false-positive reaction for glucose in the urine may occur with copper sulfate tests (Benedicts solution, Fehlings solution, or Clinitest tablets) but not with enzyme based tests such as Clinistix and Glucose Enzymatic Test Strip USP.
A history of a previous hypersensitivity reaction to any of the penicillins is a contraindication. Ampicillin is also contraindicated in infections caused by penicillinase-producing organisms.