Drug interactions
Clarithromycin + Loratadine
Severity: Minor
Clarithromycin and Loratadine: 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
Clarithromycin increases loratadine and desloratadine exposure. Despite the higher levels, clinical trials with macrolides have not shown meaningful QT effects or notable adverse events.
What this interaction means in plain words
Clarithromycin and Loratadine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Clarithromycin belongs to Anti Bacterial; Loratadine belongs to Respiratory.
Why it happens
Clarithromycin inhibits CYP3A4 (and P-glycoprotein), reducing loratadine metabolism and efflux.
What to do
No routine dose adjustment is needed. Monitor for sedation or palpitations, particularly in patients with other QT risk factors.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Clarithromycin and Loratadine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Loratadine
- Acrivastine + Loratadine Moderate
- Amobarbital + Loratadine Moderate
- Fentanyl + Loratadine Moderate
- Isocarboxazid + Loratadine Moderate
- Levoketoconazole + Loratadine Moderate
- Loratadine + Mavacamten Moderate
Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Frequently asked questions
Can I take Clarithromycin with Loratadine?
MediHelp rates the interaction as minor. Clarithromycin and Loratadine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Clarithromycin increases loratadine and desloratadine exposure. Despite the higher levels, clinical trials with macrolides have not shown meaningful QT effects or notable adverse events.
How serious is the interaction between Clarithromycin and Loratadine?
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 dose adjustment is needed. Monitor for sedation or palpitations, particularly in patients with other QT risk factors.
What other medicines interact with Loratadine?
MediHelp also lists interactions of Loratadine with, for example, Acrivastine, Amobarbital, Fentanyl. The full list is on the Loratadine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
