Buprenorphine/Naloxone is one of the most effective medications for treating opioid use disorder (OUD). Like all medications, it can cause side effects — most of which are mild and manageable. But some side effects are serious and require medical attention. This guide covers what to expect, what's normal, and when to call your doctor.

What Is Buprenorphine/Naloxone?

Buprenorphine/Naloxone is a combination medication sold under brand names like Suboxone, Zubsolv, and Bunavail. Buprenorphine is a partial opioid agonist that reduces cravings and withdrawal symptoms, while Naloxone is included to discourage misuse by injection. It's a Schedule III controlled substance available as sublingual films, sublingual tablets, and buccal films.

For a deeper look at how this medication works, see our guide on how Buprenorphine/Naloxone works.

Common Side Effects

Most people who take Buprenorphine/Naloxone experience some side effects, especially during the first few weeks. These typically improve as your body adjusts to the medication:

• Headache — one of the most frequently reported side effects
• Nausea — may occur during induction and usually decreases over time
• Vomiting — less common than nausea but can occur early in treatment
• Constipation — a common opioid-related effect; staying hydrated and eating fiber can help
• Insomnia — difficulty sleeping may occur, especially during the transition from other opioids
• Sweating — increased perspiration is common
• Oral numbness or pain — since the medication dissolves under your tongue, some mouth irritation is normal
• Tongue pain — related to the sublingual delivery method
• Dizziness — usually mild and more common when standing up quickly
• Drowsiness — avoid driving or operating heavy machinery until you know how the medication affects you

These side effects are generally mild and not a reason to stop treatment. Talk to your doctor if they persist or significantly affect your daily life.

Serious Side Effects

While uncommon, some side effects of Buprenorphine/Naloxone require immediate medical attention. Call your doctor or go to the emergency room if you experience any of the following:

• Respiratory depression — slow, shallow, or difficult breathing. This risk increases significantly when Buprenorphine/Naloxone is combined with benzodiazepines, alcohol, or other CNS depressants.
• Hepatotoxicity (liver damage) — signs include yellowing of the skin or eyes (jaundice), dark urine, light-colored stools, and upper abdominal pain. Liver function tests are typically monitored during treatment.
• Severe allergic reaction — hives, swelling of the face, lips, tongue, or throat, and difficulty breathing. Seek emergency help immediately.
• Adrenal insufficiency — symptoms include extreme fatigue, nausea, vomiting, low blood pressure, and dizziness. This is rare but can occur with long-term opioid use.
• Serotonin syndrome — if you take Buprenorphine/Naloxone with certain antidepressants (SSRIs, SNRIs) or other serotonergic drugs, watch for agitation, rapid heartbeat, high blood pressure, fever, muscle rigidity, and confusion.
• Orthostatic hypotension — a sudden drop in blood pressure when standing, which can cause fainting.
• QT prolongation — an abnormal heart rhythm that can be dangerous. Seek care if you experience palpitations, dizziness, or fainting.

The FDA boxed warning for Buprenorphine/Naloxone highlights the risk of fatal respiratory depression when combined with benzodiazepines or other CNS depressants, the risk of serious harm from intravenous misuse, and the danger of accidental ingestion by children, which can be fatal.

Side Effects in Specific Populations

Pregnant Women

Buprenorphine/Naloxone may cause neonatal opioid withdrawal syndrome in newborns. However, for pregnant women with OUD, the benefits of treatment often outweigh the risks of untreated addiction. Your doctor will discuss the safest approach — some providers prefer Buprenorphine alone (without Naloxone) during pregnancy.

Breastfeeding

Buprenorphine passes into breast milk. Your doctor will help you weigh the risks and benefits. In many cases, breastfeeding is still considered appropriate during Buprenorphine/Naloxone treatment.

Liver Disease

Patients with hepatic impairment should use Buprenorphine/Naloxone with caution. It is not recommended for patients with severe liver disease. Your doctor will likely monitor your liver function with periodic blood tests.

Older Adults

Geriatric patients may be more sensitive to side effects like sedation, dizziness, and respiratory depression. Lower doses and closer monitoring may be needed.

Children

Buprenorphine/Naloxone is not approved for patients under 16. Accidental ingestion by a child can cause a fatal overdose. Always store this medication securely out of reach of children.

How to Manage Common Side Effects

Most side effects improve within the first one to two weeks of treatment. Here are some practical tips:

• For nausea: Take the medication at the same time each day. Eating a small, bland snack beforehand may help.
• For constipation: Increase water and fiber intake. Over-the-counter stool softeners like Docusate or Polyethylene Glycol (MiraLAX) can help.
• For insomnia: Practice good sleep hygiene — consistent bedtime, no screens before bed, avoid caffeine in the afternoon.
• For dizziness: Stand up slowly, especially from a seated or lying position.
• For oral pain: Alternate the side of your mouth where you place the film or tablet. Good oral hygiene and staying hydrated help.
• For sweating: Wear breathable fabrics and stay hydrated. This often improves over time.

Never stop taking Buprenorphine/Naloxone suddenly without your doctor's guidance. Abruptly stopping can cause withdrawal symptoms and increase the risk of relapse.

Final Thoughts

Side effects are a normal part of starting any medication, and Buprenorphine/Naloxone is no exception. Most common side effects are mild and temporary. The serious side effects, while rare, are important to know about so you can act quickly if they occur.

The benefits of Buprenorphine/Naloxone in treating opioid use disorder — reduced cravings, prevented withdrawal, and lower risk of relapse and overdose — far outweigh the risks for most patients. If you're experiencing side effects that concern you, talk to your prescriber before making any changes to your treatment.

Need help finding Buprenorphine/Naloxone at a pharmacy near you? Use Medfinder to check stock availability. For more on drug interactions to watch out for, check our dedicated guide.