Drug interactions
Methamphetamine + Ritonavir
Severity: Major
Methamphetamine and Ritonavir: 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
Ritonavir strongly inhibits CYP2D6 and CYP3A4, and methamphetamine is partly cleared through CYP2D6. Methamphetamine concentrations may rise, increasing the risk of hypertension, tachycardia, arrhythmia and other stimulant toxicity.
What this interaction means in plain words
Methamphetamine and Ritonavir 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.
Methamphetamine belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Inhibition of CYP2D6-mediated metabolism of methamphetamine by ritonavir, increasing exposure.
What to do
Avoid the combination where possible. If it is used, monitor blood pressure, heart rate and cardiac symptoms and use the lowest effective methamphetamine dose.
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 Methamphetamine
- Isocarboxazid + Methamphetamine Contraindicated
- Linezolid + Methamphetamine Contraindicated
- Methamphetamine + Phenelzine Contraindicated
- Methamphetamine + Procarbazine Contraindicated
- Methamphetamine + Rasagiline Contraindicated
- Methamphetamine + Safinamide Contraindicated
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Methamphetamine with Ritonavir?
MediHelp rates the interaction as major. Methamphetamine and Ritonavir 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. Ritonavir strongly inhibits CYP2D6 and CYP3A4, and methamphetamine is partly cleared through CYP2D6. Methamphetamine concentrations may rise, increasing the risk of hypertension, tachycardia, arrhythmia and other stimulant toxicity.
How serious is the interaction between Methamphetamine and Ritonavir?
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. If it is used, monitor blood pressure, heart rate and cardiac symptoms and use the lowest effective methamphetamine dose.
What other medicines interact with Methamphetamine?
MediHelp also lists interactions of Methamphetamine with, for example, Isocarboxazid, Linezolid, Phenelzine. The full list is on the Methamphetamine page.
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