Claritin with antibiotics: interactions and safety
Antibiotic courses are common, short-term and often combined with chronic medications such as Claritin (Loratadine). Most antibiotics do not interfere meaningfully with Loratadine at 5mg, 10mg, 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 Loratadine at 5mg, 10mg.
Practical guidance
According to the prescribing information for Loratadine, an antibiotic course should be reviewed by the prescriber or pharmacist for known interactions before Claritin is co-administered. Adjusted 5mg, 10mg dosing or temporary substitution is sometimes preferred for the duration of the antibiotic course.
Frequently asked questions
Can I take Claritin during an antibiotic course? ▾
For most common antibiotics, yes. A few classes — notably macrolides and azole antifungals — alter how Loratadine is metabolised and may need a temporary 5mg, 10mg adjustment. The prescribing pharmacist should review any new antibiotic against the existing Claritin regimen.
Will antibiotics make Claritin stop working? ▾
Most antibiotics do not affect Claritin efficacy. Rifampicin and a few others can lower Loratadine levels and reduce effect; in those cases the prescriber may adjust the dose during and shortly after the antibiotic course.
More on Claritin
- With alcoholClaritin and alcohol — is it safe to drink?
- With foodShould Claritin be taken with food?
- Side effectsClaritin side effects: common, rare and warning signs
- Dosage guideClaritin dosage guide: how much to take and when
- OnsetHow fast does Claritin start working?
- DurationHow long does Claritin last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.