Drug interactions
Loratadine + Ritonavir
Severity: Minor
Loratadine and Ritonavir: 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
Ritonavir strongly inhibits CYP3A4 and may substantially raise loratadine and desloratadine exposure. Loratadine has a wide therapeutic index, but higher levels may increase sedation or, rarely, cardiac effects.
What this interaction means in plain words
Loratadine and Ritonavir have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Loratadine belongs to Respiratory; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir inhibits CYP3A4 (and P-gp), decreasing loratadine clearance.
What to do
Use standard loratadine doses without exceeding the label and monitor for sedation or palpitations.
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 Loratadine and Ritonavir, 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 Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Loratadine with Ritonavir?
MediHelp rates the interaction as minor. Loratadine and Ritonavir have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Ritonavir strongly inhibits CYP3A4 and may substantially raise loratadine and desloratadine exposure. Loratadine has a wide therapeutic index, but higher levels may increase sedation or, rarely, cardiac effects.
How serious is the interaction between Loratadine and Ritonavir?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use standard loratadine doses without exceeding the label and monitor for sedation or palpitations.
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.
