Drug interactions
Ampicillin-sulbactam + Rifampin
Severity: Minor
Ampicillin-sulbactam and Rifampin: minor interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Rifampin is a potent enzyme inducer, but ampicillin is mainly cleared unchanged by the kidneys, so a meaningful drop in levels is unlikely. Rifampin is also bacteriostatic or bactericidal depending on the organism, and in vitro antagonism with beta-lactams has been described.
What this interaction means in plain words
Ampicillin-sulbactam and Rifampin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Possible minor induction of metabolism or hepatic handling by rifampin; the mechanism is not well established.
What to do
No dose change is generally needed; monitor clinical response to the infection being treated.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Ampicillin-sulbactam
Frequently asked questions
Can I take Ampicillin-sulbactam with Rifampin?
MediHelp rates the interaction as minor. Ampicillin-sulbactam and Rifampin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Rifampin is a potent enzyme inducer, but ampicillin is mainly cleared unchanged by the kidneys, so a meaningful drop in levels is unlikely. Rifampin is also bacteriostatic or bactericidal depending on the organism, and in vitro antagonism with beta-lactams has been described.
How serious is the interaction between Ampicillin-sulbactam and Rifampin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose change is generally needed; monitor clinical response to the infection being treated.
What other medicines interact with Ampicillin-sulbactam?
MediHelp also lists interactions of Ampicillin-sulbactam with, for example, Methotrexate, Allopurinol, Bcg vaccine live. The full list is on the Ampicillin-sulbactam page.
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