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Can I take 15 and Sevodyne together?

Drug interaction guide

Taking these two medicines together can significantly increase the risk of serious side effects, particularly breathing difficulties, extreme sleepiness, and a dangerous drop in blood pressure. You may feel very dizzy, confused, or find it difficult to stay awake. In severe cases, this combination can lead to a coma or be life-threatening.

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Why this happens

Both medicines act as central nervous system (CNS) depressants. Sevodyne (buprenorphine) is a strong opioid painkiller, and '15' (commonly referring to 15mg Phenobarbital or a similar sedative) is a barbiturate. When used together, they 'stack' their effects on the brain, leading to profound sedation and a suppressed drive to breathe.

You should not take these two medicines together unless specifically instructed and closely monitored by your doctor. If you are already taking both, do not stop suddenly, but contact your doctor immediately to discuss a safe plan. Seek emergency medical help if you experience extreme drowsiness, shallow breathing, or feel like you might faint.

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Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.

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Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 14 Mar 2026 | Originally published
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