Drug interactions
Clozapine + Loxapine
Severity: Major
Clozapine and Loxapine: major interaction.
Last updated Sources: US FDA label
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
Combining two antipsychotics increases the risk of sedation, orthostatic hypotension, seizures, extrapyramidal symptoms and neuroleptic malignant syndrome. Both agents also have anticholinergic activity, and clozapine carries additional risks such as respiratory and circulatory collapse and myocarditis.
What this interaction means in plain words
Clozapine and Loxapine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Clozapine belongs to Central Nervous System; Loxapine belongs to Central Nervous System.
Why it happens
Additive dopamine D2 antagonism, CNS depression, antimuscarinic and alpha-adrenergic effects, and additive lowering of seizure threshold.
What to do
Avoid the combination unless specialist-supervised and clearly justified, using the lowest effective doses. Monitor blood pressure, sedation, seizure activity, bowel function and signs of neuroleptic malignant syndrome.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Loxapine
- Alfentanil + Loxapine Major
- Alprazolam + Loxapine Major
- Amisulpride + Loxapine Major
- Amoxapine + Loxapine Major
- Apomorphine + Loxapine Major
- Belladonna and opium + Loxapine Major
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Clozapine with Loxapine?
MediHelp rates the interaction as major. Clozapine and Loxapine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Combining two antipsychotics increases the risk of sedation, orthostatic hypotension, seizures, extrapyramidal symptoms and neuroleptic malignant syndrome. Both agents also have anticholinergic activity, and clozapine carries additional risks such as respiratory and circulatory collapse and myocarditis.
How serious is the interaction between Clozapine and Loxapine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination unless specialist-supervised and clearly justified, using the lowest effective doses. Monitor blood pressure, sedation, seizure activity, bowel function and signs of neuroleptic malignant syndrome.
What other medicines interact with Loxapine?
MediHelp also lists interactions of Loxapine with, for example, Alfentanil, Alprazolam, Amisulpride. The full list is on the Loxapine page.
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