Generic Bupropion + Naltrexone

Introduction

Bupropion + Naltrexone is a fixed‑dose combination used primarily for chronic weight management in adults. The product belongs to the weight‑loss medication group and targets the neuro‑behavioural pathways that regulate appetite, satiety and food‑related reward. In the United Kingdom, the combination is licensed for individuals with a body‑mass index (BMI) ≥ 30 kg/m², or ≥ 27 kg/m² together with at least one obesity‑related comorbidity such as hypertension, type 2 diabetes or dyslipidaemia. The two active compounds – bupropion and naltrexone – are combined in a single tablet to exploit their synergistic actions on dopaminergic, noradrenergic and opioid systems, delivering a clinically meaningful reduction in body weight when used alongside diet and exercise.

What is Bupropion + Naltrexone?

Bupropion + Naltrexone is the generic version of the well‑known branded products Contrave (U.S.) and Mysimba (Europe), containing the same active ingredients bupropion hydrochloride and naltrexone hydrochloride. Otsuka Pharmaceutical Co. developed the original branded formulation. Our online pharmacy provides this generic alternative as a cost‑effective treatment option, matching the established efficacy and safety profile of the brand‑name products while offering lower purchase prices.

How Bupropion + Naltrexone Works

Bupropion is a norepinephrine–dopamine reuptake inhibitor (NDRI). By blocking the reuptake of noradrenaline and dopamine, it increases the synaptic concentrations of these neurotransmitters, which in turn modulates the hypothalamic appetite centre and enhances energy expenditure. Naltrexone is an µ‑opioid‑receptor antagonist that blunts the opioid‑mediated reinforcement of rewarding (especially high‑fat, high‑sugar) foods. When combined, low‑dose bupropion stimulates the pro‑opioclinic pathway while naltrexone prevents the downstream activation of the reward system, producing a net reduction in food craving and an increase in satiety. Clinically, the effect emerges within a few weeks of titration, with a therapeutic plateau generally reached after 12–16 weeks of continuous use. Steady‑state plasma concentrations are achieved after approximately 5 days of daily dosing; the elimination half‑life of bupropion is 21 h (via hepatic CYP2B6) and that of naltrexone is 4 h (mainly hepatic glucuronidation).

Suitable Candidates for Bupropion + Naltrexone Treatment

The combination is appropriate for adult patients who satisfy one of the following criteria:

• BMI ≥ 30 kg/m² (obesity) irrespective of other health conditions.
• BMI ≥ 27 kg/m² with an obesity‑related comorbidity such as type 2 diabetes, hypertension, dyslipidaemia, obstructive sleep apnoea, or fatty liver disease.

Patients should already be enrolled in a structured weight‑management programme that includes dietary modification and regular physical activity. The drug is contraindicated or unsuitable in individuals with any of the following:

• A current or past diagnosis of seizure disorder, or use of other agents that lower the seizure threshold.
• Uncontrolled hypertension (systolic ≥ 170 mmHg or diastolic ≥ 100 mmHg).
• Active or a recent history of eating‑disorder (e.g., bulimia nervosa, anorexia).
• Use of opioid agonist therapy (e.g., methadone, buprenorphine) or concurrent opioid‑antagonist agents.

Clinicians must evaluate renal and hepatic function, as severe impairment may necessitate dose adjustment or avoidance.

Risks, Side Effects, and Interactions

Common

• Insomnia or altered sleep patterns
• Dry mouth
• Constipation
• Nausea or dyspepsia
• Increased blood pressure or heart rate

These events are typically mild‑to‑moderate and often improve with dose optimisation or supportive measures (e.g., hydration for dry mouth, fibre for constipation).

Rare

• Seizures (particularly in patients with pre‑existing epilepsy or on other seizure‑lowering drugs)
• Severe hypertension or hypertensive crisis
• Psychosis or mania, especially in patients with bipolar disorder

Serious

• Suicide‑related ideation or attempts (bupropion component)
• Respiratory depression when combined with opioid agonists
• Liver injury (rare, reported with naltrexone in the context of hepatitis)

Drug–Drug Interactions

• CNS stimulants (e.g., methylphenidate, amphetamines) may increase the risk of seizures.
• Monoamine‑oxidase inhibitors (MAOIs) and tricyclic antidepressants can potentiate hypertensive effects.
• Alcohol potentiates central nervous system effects and may precipitate seizures; patients should limit intake.
• Opioid agonists (e.g., methadone, buprenorphine) antagonise naltrexone’s action and reduce analgesia, potentially leading to opioid withdrawal.

Patients should disclose all medicines, including over‑the‑counter products and herbal supplements, to avoid additive risks.

Practical Use: Dosing, Missed Dose, Overdose

Standard dosing schedule (UK recommendation):

• Weeks –4: One tablet containing bupropion 150 mg + naltrexone 31.3 mg taken once daily in the morning with food.
• Weeks 5‑12: Two tablets daily (total bupropion 300 mg + naltrexone 62.6 mg), taken in the morning.

Dose escalation is performed to minimise the emergence of insomnia and anxiety. The maximum recommended daily dose is two tablets; exceeding this dose does not improve efficacy and raises the risk of adverse events.

Missed dose: If a dose is forgotten, it should be taken as soon as remembered unless it is close to the time of the next scheduled dose; in that case, skip the missed dose and continue with the regular regimen. Doubling the dose to compensate for a missed dose is discouraged.

Overdose: In the event of suspected overdose, immediately seek emergency medical assistance (999 in the UK). Presenting features may include severe hypertension, seizures, hyperthermia, or cardiovascular collapse. Management is symptomatic and supportive, with consideration of activated charcoal for recent ingestion and seizure prophylaxis per local protocols.

Practical precautions:

• Avoid high‑fat meals at the same time as the tablet, as they may affect absorption.
• Refrain from alcohol consumption exceeding 14 units per week while on therapy.
• Regularly monitor blood pressure and heart rate during titration and thereafter.

Buying Bupropion + Naltrexone from Our Online Pharmacy

Patients in the United Kingdom can obtain Bupropion + Naltrexone through our online pharmacy in UK. The service is designed to provide:

• Affordable pricing – Generic tablets are sourced at near‑manufacturer cost, resulting in a price that is typically 30 % lower than the brand‑name alternatives.
• Verified quality – All products are supplied by licensed, CE‑marked manufacturers and undergo third‑party testing for purity and potency.
• Guaranteed delivery – Discreet, fully tracked shipping is available; express parcels arrive within 7 working days, while standard airmail delivery usually takes up to 3 weeks.
• International access – Acting as a pharmacy‑broker, we partner with overseas licensed pharmacies to obtain medications not readily stocked on the NHS, while respecting patient privacy and data protection standards.

The model offers a safe, cost‑effective route for adults who have limited access to a conventional pharmacy or whose insurance coverage does not include the medication.

FAQ

• Is Bupropion + Naltrexone available in both brand‑name and generic forms in the UK?
  Yes. The branded versions are marketed as Contrave (U.S.) and Mysimba (EU). Generic tablets containing the identical bupropion + naltrexone fixed dose are produced by several CE‑certified manufacturers and can be purchased from our online pharmacy.

• What is the typical appearance of a Bupropion + Naltrexone tablet?
  The tablet is round, bicolour (often white on one side and blue on the other), debossed with the strength “150 mg/31.3 mg”. Inactive ingredients usually include lactose, magnesium stearate, and coating polymers.

• Can the medication be stored in a refrigerator?
  No. Bupropion + Naltrexone should be stored at controlled room temperature (15 °C‑30 °C), protected from moisture and direct light. Storing in a refrigerator is unnecessary and may affect tablet integrity.

• Are there any travel‑related considerations when taking Bupropion + Naltrexone?
  When travelling internationally, keep the medication in its original packaging with a copy of the prescription or pharmacist’s label. Avoid exposure to extreme heat (e.g., in a hot car) and maintain regular dosing intervals across time‑zone changes.

• Does Bupropion + Naltrexone have any impact on common drug‑testing panels?
  Bupropion can be detected on standard employment drug panels, appearing as a psychostimulant metabolite. Naltrexone is not typically screened, but both compounds may be identified in a comprehensive toxicology screen.

• Are there differences in the formulation of Bupropion + Naltrexone between regions (e.g., US vs EU)?
  The core active ingredients are identical, but excipients, tablet colour, and coating can vary. EU formulations (Mysimba) often use lactose‑based binders, while US versions may contain different polymer coatings. Such differences do not alter the pharmacokinetic profile.

• What are the legal requirements for importing Bupropion + Naltrexone into the UK for personal use?
  The medication must be authorised by the Medicines and Healthcare products Regulatory Agency (MHRA). Personal import is permitted when the product is prescribed by a UK‑registered prescriber and the quantity does not exceed a three‑month supply. Our online pharmacy ensures compliance with all import regulations.

• Is there a known contraindication for Bupropion + Naltrexone in patients of Asian ethnicity?
  No ethnicity‑specific contraindication exists. However, some Asian subpopulations exhibit reduced activity of CYP2B6, the primary enzyme metabolising bupropion, which may increase plasma concentrations. Dose titration should be cautious and guided by clinical response.

• How does Bupropion + Naltrexone compare to older weight‑loss agents such as orlistat?
  Orlistat acts by inhibiting gastrointestinal lipase, leading to reduced fat absorption, whereas Bupropion + Naltrexone modulates central reward pathways and appetite regulation. Clinical trials have shown larger mean weight‑loss percentages (≈ 5 %–10 % of baseline body weight) with Bupropion + Naltrexone compared with orlistat, which typically yields ≈ 3 % loss.

• What storage conditions are recommended for Bupropion + Naltrexone during a moving household renovation?
  Keep the tablets in a dry, temperature‑stable environment away from dust and construction fumes. A sealed container inside a cupboard (12 °C‑25 °C) is ideal; avoid storing near chemicals or strong cleaning agents that could leach into the packaging.

Glossary

CYP2B6

A liver enzyme that mediates the oxidative metabolism of bupropion; genetic variation can influence drug clearance.

Fixed‑dose combination

A pharmaceutical product that contains two or more active ingredients in a single tablet with a predetermined ratio.

Therapeutic window

The range of drug concentrations in which efficacy is achieved without unacceptable toxicity.

Ceiling effect

A phenomenon where increasing the dose above a certain point does not result in a further increase in clinical effect.

Disclaimer

The information provided about Bupropion + Naltrexone is for general knowledge only. It does not replace professional medical consultation. All treatment decisions should be made under the supervision of a qualified healthcare provider. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to Bupropion + Naltrexone for individuals who may have limited availability through traditional pharmacies, prescription‑based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication.