Buprenorphine
(Sublingual)

What is buprenorphine?

Buprenorphine is a medicine used to treat opioid use disorder. It belongs to the opioid class of medicines, but it works differently from opioids such as morphine, oxycodone, or heroin. It is considered a first-line, evidence-based treatment that significantly reduces overdose risk, improves functioning, and supports recovery. Buprenorphine and methadone are the two main medicines used in opioid dependence treatment (ODT), also called opioid substitution therapy (OST).

Sublingual buprenorphine is taken by placing a film or tablet under the tongue (or between the cheek and gum) and allowing it to dissolve. It must not be swallowed; absorption through the gut is very poor.

Suboxone®: buprenorphine with naloxone

Most people are prescribed Suboxone, which contains buprenorphine and naloxone together. The naloxone component is included to deter misuse: if the film is dissolved as directed under the tongue, naloxone has almost no effect. However, if the product is injected, the naloxone is absorbed and can trigger sudden opioid withdrawal.

How does it work?

Buprenorphine is a partial opioid agonist. This means it activates opioid receptors in the brain, which:

• Reduces cravings for opioids
• Prevents or eases withdrawal symptoms
• Reduces the effect (the "high") if other opioids are taken on top
• Has a much lower risk of respiratory depression (slowed breathing) than full agonists

Because it binds tightly to opioid receptors (high receptor affinity), it can actually precipitate withdrawal if taken too soon after a full opioid agonist. Your doctor will advise you on timing.

Starting buprenorphine

You will usually be asked to be in mild-to-moderate opioid withdrawal before your first dose (typically a score of ≥8 on the Clinical Opiate Withdrawal Scale). This is to reduce the risk of precipitated withdrawal. Your doctor will guide you through this process and discuss the timing carefully.

There are also low-dose or "microdose" starting protocols available for people who cannot easily stop their current opioid before starting. Your doctor can explain whether this is an option for you.

Dosing

• Suboxone films come in doses of 2 mg/0.5 mg and 8 mg/2 mg (buprenorphine/naloxone).
• Most people stabilise on a once-daily dose between 8 mg and 24 mg.
• It is taken once each day and dissolves under the tongue in 5–10 minutes.
• Avoid eating, drinking, or smoking until the film has fully dissolved.
• After several weeks of stability, some people can transition to alternate-day or less frequent dosing. Ask your doctor.

Common side effects

• Headache
• Nausea
• Sweating
• Constipation
• Difficulty sleeping
• Mouth soreness (under the tongue)
• Feeling tired or drowsy
• Mild withdrawal feelings when changing dose

Many side effects settle within the first few weeks. Tell your doctor if they persist or are troublesome.

Important safety information

• Driving: Buprenorphine may affect your ability to drive, especially when first starting or after a dose change. Do not drive until you know how this medication affects you.
• Pregnancy: Buprenorphine is used in pregnancy and is generally considered safer than continued illicit opioid use, but requires specialist monitoring. Tell your doctor immediately if you are or may become pregnant.
• Dental health: Sublingual medicines can affect tooth enamel over time. Rinse your mouth with water after each dose and maintain regular dental check-ups.
• Storage: Store at room temperature, out of reach of children and others who have not been prescribed it. Buprenorphine is a controlled substance. Do not share it.

How long will I need to take it?

There is no fixed duration. Many people benefit from taking buprenorphine for an extended period (months to years), and this is associated with better outcomes. Stopping prematurely greatly increases the risk of relapse and overdose. Any decisions about reducing or stopping should be made with your psychiatrist.

Dispensing and prescribing

In Victoria, your prescriber needs a permit for your treatment, and your doses come from one pharmacy that you agree on together. At first, doses are usually taken at the pharmacy, where the pharmacist watches you take them (supervised dosing). As your treatment becomes stable, take-away doses may be arranged. A prescription can include repeats covering up to six months, and your prescriber will still review you regularly.

• Cost: under the PBS you pay the usual PBS co-payment. Community pharmacies cannot charge extra dispensing or dosing fees for these medicines.
• Missed doses: if you miss four or more days in a row, you need to see your prescriber before the pharmacy can give you another dose, because your body's tolerance may have changed.
• Take-away doses: keep them locked away (in a cupboard, drawer, cash box or safe) and out of reach of children. Even a small dose can cause death if a child takes it. Lost or stolen take-away doses may not be replaced.
• Naloxone: keep naloxone at home and show the people you live with how to use it. It is free in Victoria through the Take-Home Naloxone Program.

Other questions?

Please bring any questions to your next appointment. You can also contact the rooms on 03 9834 3600. In an emergency or crisis, call 000 or go to your nearest hospital emergency department.

For a problem with your pharmacy or prescriber that you cannot sort out together, PAMS (Pharmacotherapy Advocacy, Mediation and Support, run by Harm Reduction Victoria) is a free, confidential phone service on 1800 443 844. For alcohol and drug counselling or referral at any hour, call DirectLine on 1800 888 236 (24 hours, free and confidential).

Clinical content informed by: the Australian Government Department of Health, National Guidelines for Medication-Assisted Treatment of Opioid Dependence (2014); the Victorian Department of Health, Victorian Opioid Dependence Treatment Guidelines (2026); and the Therapeutic Goods Administration (TGA) approved product information for Suboxone® (Indivior). These sources are publicly available at health.gov.au, health.vic.gov.au and tga.gov.au.