Allegra with antibiotics: interactions and safety
Antibiotic courses are common, short-term and often combined with chronic medications such as Allegra (Fexofenadine). Most antibiotics do not interfere meaningfully with Fexofenadine at 30mg, 60mg, 120mg, 180mg, 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 Allergy and Antihistamines agents. Rifampicin has the opposite effect, accelerating metabolism. Most penicillins, cephalosporins, fluoroquinolones and tetracyclines have no clinically meaningful interaction with Fexofenadine at 30mg, 60mg, 120mg, 180mg.
Practical guidance
According to the prescribing information for Fexofenadine, an antibiotic course should be reviewed by the prescriber or pharmacist for known interactions before Allegra is co-administered. Adjusted 30mg, 60mg, 120mg, 180mg dosing or temporary substitution is sometimes preferred for the duration of the antibiotic course.
Frequently asked questions
Can I take Allegra during an antibiotic course? ▾
For most common antibiotics, yes. A few classes — notably macrolides and azole antifungals — alter how Fexofenadine is metabolised and may need a temporary 30mg, 60mg, 120mg, 180mg adjustment. The prescribing pharmacist should review any new antibiotic against the existing Allegra regimen.
Will antibiotics make Allegra stop working? ▾
Most antibiotics do not affect Allegra efficacy. Rifampicin and a few others can lower Fexofenadine levels and reduce effect; in those cases the prescriber may adjust the dose during and shortly after the antibiotic course.
More on Allegra
- With alcoholAllegra and alcohol — is it safe to drink?
- With foodShould Allegra be taken with food?
- Side effectsAllegra side effects: common, rare and warning signs
- Dosage guideAllegra dosage guide: how much to take and when
- OnsetHow fast does Allegra start working?
- DurationHow long does Allegra last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.