Drug interactions
Orlistat + Valproic acid
Severity: Moderate
Orlistat and Valproic acid: 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
Orlistat has been associated with breakthrough seizures in patients on antiepileptic drugs, including valproate. Reduced absorption of the antiepileptic is the proposed explanation, though this is not firmly established. Loss of seizure control can be serious.
What this interaction means in plain words
Orlistat and Valproic acid 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.
Orlistat belongs to Miscellaneous; Valproic acid belongs to Central Nervous System.
Why it happens
Orlistat inhibits gastrointestinal lipases and may reduce absorption of antiepileptic drugs, though the mechanism is not established.
What to do
Monitor seizure frequency and valproate concentrations when orlistat is started or stopped. Consider an alternative weight-loss approach in patients with difficult-to-control epilepsy.
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 Valproic acid
- Ertapenem + Valproic acid Contraindicated
- Imipenem / cilastatin / relebactam + Valproic acid Contraindicated
- Imipenem / cilastatin + Valproic acid Contraindicated
- Meropenem / vaborbactam + Valproic acid Contraindicated
- Meropenem + Valproic acid Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Valproic acid Major
Other interactions of Orlistat
- Cyclosporine + Orlistat Major
- Cyclosporin + Orlistat Major
- Orlistat + Triheptanoin Major
- Amiodarone + Orlistat Moderate
- Beta carotene + Orlistat Moderate
- Carbamazepine + Orlistat Moderate
Frequently asked questions
Can I take Orlistat with Valproic acid?
MediHelp rates the interaction as moderate. Orlistat and Valproic acid 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. Orlistat has been associated with breakthrough seizures in patients on antiepileptic drugs, including valproate. Reduced absorption of the antiepileptic is the proposed explanation, though this is not firmly established. Loss of seizure control can be serious.
How serious is the interaction between Orlistat and Valproic acid?
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 seizure frequency and valproate concentrations when orlistat is started or stopped. Consider an alternative weight-loss approach in patients with difficult-to-control epilepsy.
What other medicines interact with Valproic acid?
MediHelp also lists interactions of Valproic acid with, for example, Ertapenem, Imipenem / cilastatin / relebactam, Imipenem / cilastatin. The full list is on the Valproic acid page.
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