Substitute prescribing

Substitute prescribing or Opioid Substitution Therapy (OST) is defined as the administration of a prescribed (daily) dosage of opioid medicines to patients with opioid dependence problems. Two main medications used are methadone and buprenorphine (Subutex/subbies/suboxone). Some people are able to achieve abstinence quickly with OST; many others need long-term support and long-term opioid substitute prescribing. The main reason that OST is part of guidelines is that it has been shown to reduce harms of opioid misuse. Some people want to pursue this kind of treatment and others are interested in abstinence. Choice is very important.

  • Types of substitute prescribing drugs

    The two main prescription medications used in the UK to replace opioids are methadone and buprenorphine.

    Methadone is very well known. It might pose an excess risk of death from overdose at the start of treatment if the initial doses are too high or if there is illicit opioid use alongside the methadone.

    Buprenorphine is more modern than methadone but may be less effective in keeping patients in treatment* but studies show it has lower risk of death from overdose than methadone (or illicit opioids).


    Buprenorphine (‘Subutex’ or ‘Suboxone’) is from the opioid family but it has both opioid-like effects (“agonist”) but also opioid blocking effects (“antagonist”). It is therefore an “agonist-antagonist” of opioid receptors in the brain and has been used in opioid drug misuse treatment since the 1970s, usually for heroin.
    Because of this mixed “agonist-antagonist” effect, buprenorphine use is associated with significantly lower risks of fatal overdose. When prescribed, it is administered under the tongue. Some users find its lack of euphoric effect frustrating, just like methadone, and there is often use of heroin ‘on top’.


    Methadone is prescribed to people who are misusing opioids, usually heroin. It is usually a green liquid that is taken orally, sometimes under the supervision of a pharmacist. Methadone is a manufactured ‘synthetic’ opioid that is almost exclusively used in the UK to treat opioid misuse. It is used as a substitute for the opioid (most commonly heroin) and hence is called “opioid substitute therapy” or “OST”. It has similar effects on the brain as heroin and other strong opioids but doesn’t give the same high . Therefore it is seen as a safer alternative to heroin and can reduce some of the massive harms from heroin misuse such as risks to the patient’s mental and physical health, damage to the patient’s family, and damage to society such as crime. It can either be prescribed as a long-term substitute or as a planned long term detox to come off opioids where the dose of methadone is slowly reduced over weeks, months, or years.

  • Effects and Health risks

    The effects of methadone can include:

    • A feeling of lethargy or slowing down of body functioning and thinking
    • Reducing pain
    • Reducing psychological distress or anxiety
    • Feelings of relaxation and detachment

    Physical health risks

    • Taking methadone on prescription has been shown to significantly reduce the harms from opioid misuse. However, taking it illegally does involve risks. Prescribed methadone is carefully and safely manufactured and controlled so you know exactly what you are getting. Methadone that is bought on the black market can be ‘cut’ with cheaper substance to make it “go further”. Methadone from the street might have other effects such as having a higher risk of:Taking more than intended and feeling drowsy
    • Nausea or vomiting
    • Overdose and death
    • ‘Boosted’ effects when mixed with other addictive substances such as benzodiazepines, fentanyl, or even “fillers” which bulk up the liquid but don’t have an opioid-life effect. Sometimes these added chemicals can cause allergic reactions.
  • Signs to look out for

    Methadone and buprenorphine are opioids, so they share signs of misuse with other opioids, such as:

    • Fatigue, followed by patterns of alertness
    • Shallow or laboured breathing
    • Nausea & vomiting
    • Small, constricted pupils
    • Appearance of “distant” gazing eyes
    • Lack of motivation
    • Distance from old friends and family members
    • Disorientation or dizziness
    • Difficulty speaking, slurred speech
    • Lack of memory, forgetting things or not remembering important events or matters
    • Lack of interest in the future or what comes next
    • Unkempt self-image, lack of hygiene, loss of self-discipline
    • Sometimes injection wounds if they are injected
    • Infections on the skin and deeper tissue from injecting
  • Detox and Withdrawal

    Withdrawal from methadone or buprenorphine

    Withdrawal symptoms from methadone or buprenorphine usually occur a bit more slowly than for heroin. Withdrawal produces flu-like symptoms and can include:

    • Tremors / shakes
    • Restlessness
    • Muscle spasms causing jerks/kicking
    • Widespread pains
    • Diarrhoea
    • Vomiting
    • Tummy cramps
    • Sweating
    • Runny nose
    • Insomnia

    These physical symptoms peak in a few days but the cravings can last long term.


    At The BONDS Clinic, we try hard to control this long list of withdrawal symptoms from methadone or buprenorphine. We specialise in detox over 1-2 weeks using non-addictive medication to make it as comfortable as possible, and published evidence shows that even an early version of the Bonds protocols was very well tolerated in opioid detox: 97% of patients did not report pain during a Bonds detox from opioids. (reference again as before: Beaini AY et al (2000, October). A compressed opiate detoxification regime with naltrexone maintenance: patient tolerance, risk assessment and abstinence rates. Addiction Biology, 1;5(4):451-62 ). Higher doses of methadone can take an extra week.

    Once the drugs are out of your system (can be two weeks for methadone), you can then have oral naltrexone which blocks the effects of any opioids for opioid misuse, and naltrexone may reduce cravings for a wide range of other misuse, both prescription and non-prescription drug or alcohol misuse, and therefore may be useful to support abstinence.

Advice from our consultant

Programme model

Programme model

Our programme model is tailored to the individual’s needs. Our detox varies depending on whether the substance is a lone problem or is accompanied by misuse of other substances, the amount the patient is using, and if there any underlying mental health issues. The internal audits of the BONDS treatment protocols of many years have shown that approximately 70% of patients with alcohol or substance misuse also have an underlying mental health disorder. This combination of addiction and a mental health disorder is called Dual Diagnosis. A typical detox program at The Bonds Clinic consists of a 7-14 day with dual diagnosis assessment, then an out-patient consolidation & relapse prevention stage including talking therapy, and often includes Naltrexone therapy.

View programme model

Meet the team

Our core multi-disciplinary team is led by a Consultant Psychiatrist, specialised GPs and includes a Registered Mental Health Nurse and a Substance Misuse and Dual Diagnosis Practitioner and Therapist. We also work with a network of highly skilled practitioners to develop a personal treatment programme to suit you.

Meet the team
Meet the team

Know someone with an addiction?

The BONDS Clinic work with you and your family, offering a comprehensive Family Support Program.It can be challenging if a loved one has an addiction; it can sometimes have a negative effect on relationships, home environments and family dynamics. It may be difficult to spot the signs and how best to approach them and help them on a path towards recovery. The BONDS Clinic feel that we should all be empowered to support and seek treatment for our loved ones when they need it most but also remember we are here for you as well. If you think a loved one may have an addiction, we are here to help.


(reference Mattick RP, Breen C, Kimber J, Davoli M. Buprenorphine maintenance versus placebo or methadone maintenance for opioid dependence. Cochrane Database Syst Rev 2014;357:CD002207.pmid:24500948.)