5-alpha-reductase inhibitor (type II)
Finasteride with antibiotics: interactions and safety
Antibiotic courses are common, short-term and often combined with chronic medications such as Finasteride (Finasteride). Most antibiotics do not interfere meaningfully with Finasteride at 1mg, but a few classes do, and a small number of combinations are best avoided.
Common antibiotic interactions
Macrolides (clarithromycin, erythromycin) and certain antifungals can inhibit hepatic metabolism (CYP3A4) and raise plasma levels of many medications including some 5-alpha-reductase inhibitor (type II) agents. Rifampicin has the opposite effect, accelerating metabolism. Most penicillins, cephalosporins, fluoroquinolones and tetracyclines have no clinically meaningful interaction with Finasteride at 1mg.
Practical guidance
According to the prescribing information for Finasteride, an antibiotic course should be reviewed by the prescriber or pharmacist for known interactions before Finasteride is co-administered. Adjusted 1mg dosing or temporary substitution is sometimes preferred for the duration of the antibiotic course.
Frequently asked questions
Can I take Finasteride during an antibiotic course? ▾
For most common antibiotics, yes. A few classes — notably macrolides and azole antifungals — alter how Finasteride is metabolised and may need a temporary 1mg adjustment. The prescribing pharmacist should review any new antibiotic against the existing Finasteride regimen.
Will antibiotics make Finasteride stop working? ▾
Most antibiotics do not affect Finasteride efficacy. Rifampicin and a few others can lower Finasteride levels and reduce effect; in those cases the prescriber may adjust the dose during and shortly after the antibiotic course.
Products containing Finasteride
More on Finasteride
- With alcoholFinasteride and alcohol — is it safe to drink?
- With foodShould Finasteride be taken with food?
- Side effectsFinasteride side effects: common, rare and warning signs
- Dosage guideFinasteride dosage guide: how much to take and when
- OnsetHow fast does Finasteride start working?
- DurationHow long does Finasteride last?
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