Drug interactions
Ampicillin + Typhoid vaccine live
Severity: Moderate
Ampicillin and Typhoid vaccine live: moderate 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
Oral live typhoid vaccine (Ty21a) is susceptible to ampicillin, and antibiotic exposure can reduce the vaccine strain's viability and weaken the immune response. This may leave the recipient inadequately protected.
What this interaction means in plain words
Ampicillin and Typhoid vaccine live can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Antibacterial activity reduces survival and replication of the live attenuated Salmonella vaccine strain in the gut.
What to do
Give the live oral typhoid vaccine only after the antibiotic course has finished, or use the inactivated injectable vaccine if vaccination cannot wait.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Ampicillin
- Allopurinol + Ampicillin Moderate
- Ampicillin + Bcg vaccine live Moderate
- Ampicillin + Chloramphenicol Moderate
- Ampicillin + Chloroquine Moderate
- Ampicillin + Cholera vaccine Moderate
- Ampicillin + Demeclocycline Moderate
Frequently asked questions
Can I take Ampicillin with Typhoid vaccine live?
MediHelp rates the interaction as moderate. Ampicillin and Typhoid vaccine live can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Oral live typhoid vaccine (Ty21a) is susceptible to ampicillin, and antibiotic exposure can reduce the vaccine strain's viability and weaken the immune response. This may leave the recipient inadequately protected.
How serious is the interaction between Ampicillin and Typhoid vaccine live?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Give the live oral typhoid vaccine only after the antibiotic course has finished, or use the inactivated injectable vaccine if vaccination cannot wait.
What other medicines interact with Ampicillin?
MediHelp also lists interactions of Ampicillin with, for example, Allopurinol, Bcg vaccine live, Chloramphenicol. The full list is on the Ampicillin page.
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