Drug interactions
Cetirizine + Isocarboxazid
Severity: Moderate
Cetirizine and Isocarboxazid: moderate 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
MAO inhibitors can intensify and prolong the anticholinergic and sedative effects of antihistamines. Cetirizine is less anticholinergic than first-generation agents, but additive drowsiness and psychomotor impairment may still occur.
What this interaction means in plain words
Cetirizine and Isocarboxazid can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Cetirizine belongs to Respiratory; Isocarboxazid belongs to Central Nervous System.
Why it happens
Additive pharmacodynamic CNS depression, with MAO inhibition possibly potentiating antihistamine anticholinergic effects.
What to do
Monitor for excessive sedation, dizziness and anticholinergic effects when starting cetirizine in a patient on isocarboxazid. Advise against driving until the response is known, and reduce the cetirizine dose if sedation occurs.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Cetirizine
- Acrivastine + Cetirizine Moderate
- Amisulpride + Cetirizine Moderate
- Asenapine + Cetirizine Moderate
- Avapritinib + Cetirizine Moderate
- Benzhydrocodone / acetaminophen + Cetirizine Moderate
- Brexpiprazole + Cetirizine Moderate
Other interactions of Isocarboxazid
- 5-HTP + Isocarboxazid Contraindicated
- Amitriptyline + Isocarboxazid Contraindicated
- Amobarbital + Isocarboxazid Contraindicated
- Amoxapine + Isocarboxazid Contraindicated
- Apraclonidine + Isocarboxazid Contraindicated
- Atomoxetine + Isocarboxazid Contraindicated
Frequently asked questions
Can I take Cetirizine with Isocarboxazid?
MediHelp rates the interaction as moderate. Cetirizine and Isocarboxazid can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. MAO inhibitors can intensify and prolong the anticholinergic and sedative effects of antihistamines. Cetirizine is less anticholinergic than first-generation agents, but additive drowsiness and psychomotor impairment may still occur.
How serious is the interaction between Cetirizine and Isocarboxazid?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for excessive sedation, dizziness and anticholinergic effects when starting cetirizine in a patient on isocarboxazid. Advise against driving until the response is known, and reduce the cetirizine dose if sedation occurs.
What other medicines interact with Cetirizine?
MediHelp also lists interactions of Cetirizine with, for example, Acrivastine, Amisulpride, Asenapine. The full list is on the Cetirizine page.
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