Drug interactions
Penicillin g + Willow bark
Severity: Minor
Penicillin g and Willow bark: 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
Willow bark contains salicin, which is converted to salicylates in the body. Salicylates compete with penicillins for renal tubular secretion and may slightly raise penicillin concentrations. The effect is usually small at the salicylate doses reached with typical herbal use.
What this interaction means in plain words
Penicillin g and Willow bark 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
Salicylates derived from willow bark compete with penicillin G for renal tubular anion secretion, lowering its clearance.
What to do
No routine adjustment is needed at usual doses. Monitor for penicillin adverse effects if high doses of willow bark are used or renal function is impaired.
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 Penicillin g
- Amifampridine + Penicillin g Moderate
- Amiloride + Penicillin g Moderate
- Bcg vaccine live + Penicillin g Moderate
- Cholera vaccine + Penicillin g Moderate
- Colestipol + Penicillin g Moderate
- Deflazacort + Penicillin g Moderate
Frequently asked questions
Can I take Penicillin g with Willow bark?
MediHelp rates the interaction as minor. Penicillin g and Willow bark have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Willow bark contains salicin, which is converted to salicylates in the body. Salicylates compete with penicillins for renal tubular secretion and may slightly raise penicillin concentrations. The effect is usually small at the salicylate doses reached with typical herbal use.
How serious is the interaction between Penicillin g and Willow bark?
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 routine adjustment is needed at usual doses. Monitor for penicillin adverse effects if high doses of willow bark are used or renal function is impaired.
What other medicines interact with Penicillin g?
MediHelp also lists interactions of Penicillin g with, for example, Amifampridine, Amiloride, Bcg vaccine live. The full list is on the Penicillin g page.
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