Medications That Transform Treatment Outcomes for Opioid Use Disorder
                     Medications Used to Treat 
Opioid Use Disorder
Medication-assisted treatment (MAT) is a vital approach for addressing 
opioid use disorder. This presentation examines the efficacy, mechanisms, 
and practical applications of the medications currently approved for OUD 
treatment in the United Kingdom and beyond.
Understanding Opioid Use Disorder 
(OpOioiUd UDse D)isorder is a chronic, relapsing brain disorder characterised by the compulsive use of 
opioids despite harmful consequences. It involves physical dependence, psychological cravings, and 
significant behavioural changes.
Diagnostic Criteria Health Impact Societal Impact
• Inability to control opioid use • Increased risk of overdose • NHS burden (£300+ million 
• Continued use despite and death annually)
negative consequences • Infectious disease • Lost productivity
• Development of tolerance transmission • Family disruption
• Withdrawal symptoms when • Mental health comorbidities • Criminal justice involvement
use stops • Cardiovascular 
complications
In the UK, approximately 138,000 people received treatment for opioid dependence in 
2020/21.
Role of Medications in OUD Treatment
Medications are a cornerstone of effective OUD treatment, working in tandem with 
psychosocial interventions to address both the biological and behavioural aspects of addiction.
Normalise Brain Function
Restore balance to brain circuits disrupted by opioid misuse
Reduce Cravings
Diminish psychological urges to use opioids
Medication-assisted treatment has been shown to decrease 
Manage Withdrawal opioid use, opioid-related overdose deaths, criminal activity, 
and infectious disease transmission.
Alleviate physical symptoms during detoxification
Overview of FDA-Approved Medications
Three primary medications have been approved for OUD treatment, each with distinct mechanisms of action and delivery methods.
1 2 3
Methadone Buprenorphine Naltrexone
Type: Full opioid agonist Type: Partial opioid agonist Type: Opioid antagonist
Duration: Since 1960s in UK Duration: Since early 2000s Duration: Since 1984 (ER version 
more recent)
Availability: Specialised clinics, daily Availability: GP prescribing, 
dosing initially pharmacy dispensing Availability: Specialist prescribing
Formulation: Liquid, tablets Formulation: Sublingual tablets, Formulation: Oral tablets, extended-
film, implant release injection
NICE guidelines recommend that all three medications be available as treatment options, with selection based on individual patient 
factors and preferences.
Methadone
How It Works
As a full opioid agonist, methadone activates the same 
receptors as heroin or morphine, but with a slower onset and 
longer duration, preventing withdrawal while reducing 
Aeudpmhoirniai.stration
• Daily supervised consumption initially
• Dispensed through specialised clinics or community 
• pAvhearramgaec imesaintenance dose: 60-120mg daily
Evidence Base
Longest-established treatment with robust evidence 
showing 70% reduction in mortality and significant 
decreases in illicit opioid use.
Considerations: Requires careful dose titration. Risk of respiratory depression if misused. Potential for QT interval prolongation. Significant drug 
interactions.
Buprenorphine & 
Buprenorphine/Naloxone 
(Suboxone)
Mechanism of Action
Buprenorphine is a partial opioid agonist with high receptor affinity but 
limited activity, creating a "ceiling effect" that reduces overdose risk while 
managing withdrawal and cravings.
When combined with naloxone (as in Suboxone), the formulation 
discourages injection misuse, as naloxone precipitates withdrawal when 
injected but has minimal effect when taken sublingually as prescribed.
Advantages
• Lower overdose risk than methadone
• Can be prescribed by GPs with special training
• Easier transition to abstinence-based treatments
• Fewer drug interactions
• Less stigmatising collection process
Extended-Release 
Naltrexone
Unique Mechanism
Unlike methadone and buprenorphine, naltrexone is an opioid antagonist that 
blocks opioid receptors completely, preventing any euphoric effects if opioids 
are used.
Extended-Release Formulation
Monthly intramuscular injection (Vivitrol) maintains therapeutic blood levels for 
28 days, addressing the poor adherence issues associated with daily oral 
naltrexone.
Advantages Challenges
• No physical dependence • Requires complete detoxification first
• No potential for misuse • Risk of overdose if treatment stops
• Convenient monthly dosing • Limited availability in the UK
• Suitable for highly • Higher cost than other options
motivated patients
Extended-release naltrexone is particularly suitable for patients who have completed 
detoxification and are committed to abstinence, such as healthcare professionals, individuals in 
safety-sensitive occupations, or those with strong recovery support systems.
Other Medications & Supportive 
Treatments
Lofexidine (BritLofex) Adjunctive 
Medications
An alpha-2 adrenergic agonist approved specifically for Used to manage specific withdrawal symptoms:
managing opioid withdrawal symptoms:
Symptom Medication
• Reduces autonomic withdrawal symptoms like 
sweating, chills, and muscle aches Nausea/vomiting Ondansetron, 
metoclopramide
• Non-opioid alternative for short-term detoxification Diarrhoea Loperamide
• sTyuppipcoarllty used for 7-10 days during acute withdrawal
Muscle pain NSAIDs, paracetamol
• Can be combined with symptomatic medications
Anxiety/insomnia Short-term 
benzodiazepines
The NHS Addiction Provider Alliance recommends individualised symptom management approaches alongside 
evidence-based medications for opioid use disorder.
Comparing OUD 
MSelecetiond of ithce oaptimtail omednicastion should be based on individual patient factors, preferences, and treatment history.
Feature Methadone Buprenorphine Naltrexone ER
Receptor action Full agonist Partial agonist Antagonist
Overdose risk Higher Moderate Lower
Flexibility Daily dosing Daily to monthly Monthly
Accessibility Most restricted Moderate Least restricted
Retention rates 60-80% 50-70% 30-50%
Key Considerations: Patient preferences, treatment history, comorbidities, psychosocial support, access to care, cost, and 
treatment goals (harm reduction vs. abstinence) should all factor into medication selection.
The most effective treatment approaches combine appropriate medication with counselling, peer support, and addressing 
social determinants of health.
Contact Us 
Mark Leeds, D.O.
3290 NE 33rd St, Fort 
Lauderdale, FL 33308
+1 954 776 6226
[email protected]
DrLeeds.com