Drug interactions
Dolutegravir + Phenobarbital
Severity: Major
Dolutegravir and Phenobarbital: 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
Phenobarbital is an enzyme inducer that can substantially lower dolutegravir concentrations. Reduced exposure may lead to loss of HIV suppression and emergence of integrase resistance.
What this interaction means in plain words
Dolutegravir and Phenobarbital 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.
Why it happens
Induction of UGT1A1 and CYP3A4 increases dolutegravir metabolism.
What to do
Avoid the combination where possible and choose a non-inducing anticonvulsant. If it cannot be avoided, consider dolutegravir 50 mg twice daily with close viral load monitoring.
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 Dolutegravir
Frequently asked questions
Can I take Dolutegravir with Phenobarbital?
MediHelp rates the interaction as major. Dolutegravir and Phenobarbital 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. Phenobarbital is an enzyme inducer that can substantially lower dolutegravir concentrations. Reduced exposure may lead to loss of HIV suppression and emergence of integrase resistance.
How serious is the interaction between Dolutegravir and Phenobarbital?
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 where possible and choose a non-inducing anticonvulsant. If it cannot be avoided, consider dolutegravir 50 mg twice daily with close viral load monitoring.
What other medicines interact with Dolutegravir?
MediHelp also lists interactions of Dolutegravir with, for example, Dofetilide, Aluminum hydroxide, Atidarsagene autotemcel. The full list is on the Dolutegravir page.
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