Drug interactions
Phenobarbitone + Riociguat
Severity: Moderate
Phenobarbitone and Riociguat: 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
Phenobarbitone is a strong inducer of CYP3A and other metabolic enzymes and may substantially lower riociguat plasma concentrations. This can reduce the pulmonary vasodilator effect and compromise control of pulmonary hypertension.
What this interaction means in plain words
Phenobarbitone and Riociguat 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.
Phenobarbitone belongs to Central Nervous System; Riociguat belongs to Cardiovascular.
Why it happens
Enzyme induction (CYP3A and related pathways) increases riociguat clearance and lowers exposure.
What to do
Monitor clinical response and symptoms of pulmonary hypertension, and consider an alternative anticonvulsant where feasible. If the combination is needed, titrate riociguat to effect with blood pressure monitoring, and reassess the dose if phenobarbitone is stopped.
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 Riociguat
- Avanafil + Riociguat Contraindicated
- Dipyridamole + Riociguat Contraindicated
- Isosorbide dinitrate + Riociguat Contraindicated
- Isosorbide mononitrate + Riociguat Contraindicated
- Nitroglycerin + Riociguat Contraindicated
- Riociguat + Sildenafil Contraindicated
Other interactions of Phenobarbitone
- Cabotegravir + Phenobarbitone Contraindicated
- Doravirine + Phenobarbitone Contraindicated
- Isavuconazole + Phenobarbitone Contraindicated
- Darolutamide + Phenobarbitone Major
- Finerenone + Phenobarbitone Major
- Ivacaftor + Phenobarbitone Major
Frequently asked questions
Can I take Phenobarbitone with Riociguat?
MediHelp rates the interaction as moderate. Phenobarbitone and Riociguat 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. Phenobarbitone is a strong inducer of CYP3A and other metabolic enzymes and may substantially lower riociguat plasma concentrations. This can reduce the pulmonary vasodilator effect and compromise control of pulmonary hypertension.
How serious is the interaction between Phenobarbitone and Riociguat?
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 clinical response and symptoms of pulmonary hypertension, and consider an alternative anticonvulsant where feasible. If the combination is needed, titrate riociguat to effect with blood pressure monitoring, and reassess the dose if phenobarbitone is stopped.
What other medicines interact with Riociguat?
MediHelp also lists interactions of Riociguat with, for example, Avanafil, Dipyridamole, Isosorbide dinitrate. The full list is on the Riociguat page.
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