Formulary
Naltrexone hydrochloride: Indications, Dosing, Side Effects and Interactions
Naltrexone is an opioid-receptor antagonist.
MedNext Academy | 3 min read
Naltrexone hydrochloride: Indications, Dosing, Side Effects and Interactions
Naltrexone is an opioid-receptor antagonist.
Drug action
Naltrexone is an opioid-receptor antagonist.
Indications and dose
**Adjunct to prevent relapse in formerly opioid-dependent patients (who have remained opioid-free**
- **Adult** (By Mouth): for at least 7-10 days) (initiated under specialist supervision) Initially 25 mg daily, then increased to 50 mg daily, total weekly dose may be divided and given on 3 days of the week for improved compliance (e.g. 100 mg on Monday and Wednesday, and 150 mg on Friday); maximum 350 mg per week.
**Adjunct to prevent relapse in formerly alcohol-dependent patients (initiated under specialist supervision)**
- **Adult** (By Mouth): 25 mg once daily on the first day, then increased if tolerated to 50 mg daily.
**Gambling-related harm (under expert supervision)**
- **Adult** (By Mouth): Initially 25 mg once daily for 3 days, then increased if tolerated to 50 mg once daily for 4-6 months, higher doses up to a max. of 150 mg daily may be given where clinically indicated.
Cautions
Concomitant use of opioids Cautions, further information Concomitant use of opioids Concomitant use of opioids should be avoided but increased dose of opioid analgesic may be required for pain-manufacturer advises to monitor for opioid intoxication.
Contraindications
Patients currently dependent on opioids
Side effects
Common or very common Abdominal pain; anxiety; appetite abnormal; arthralgia; asthenia; chest pain; chills; constipation; diarrhoea; dizziness; eye disorders; headache; hyperhidrosis; mood altered; myalgia; nausea; palpitations; sexual dysfunction; skin reactions; sleep disorders; tachycardia; thirst; vomiting Uncommon Alopecia; confusion; cough; depression; drowsiness; dry mouth; dysphonia; dyspnoea; ear discomfort; eye discomfort; eye swelling; feeling hot; fever; flatulence; flushing; hallucination; hepatic disorders; lymphadenopathy; nasal complaints; oropharyngeal pain; pain; paranoia; peripheral coldness; seborrhoea; sinus disorder; sputum increased; tinnitus; tremor; ulcer; urinary disorders; vertigo; vision disorders; weight changes; yawning Rare or very rare Immune thrombocytopenic purpura; rhabdomyolysis; suicidal behaviours Frequency not known Withdrawal syndrome
Interactions
**Severe interactions:**
- Data from a safety and tolerability study of co-administration of naltrexone with acamprosate in non-treatment seeking, alcohol dependent individuals showed that naltrexone administration...
**Other interactions (5):**
- Methadone in substitution treatment: There is a risk of onset of withdrawal symptoms.
- Combinations not recommended: Concomitant use of naltrexone with central antihypertensives (alpha-methyldopa) is not recommended.
- Combinations where caution is advised: Concomitant use of naltrexone with barbiturates, benzodiazepines, anxiolytics other than benzodiazepines (e.g.
- Interaction with other psychopharmacological agents (e.g.
- Currently, interactions between naltrexone and alcohol are not known.
Pregnancy
Use only if benefit outweighs risk.
Breast feeding
Avoid-potential toxicity.
Hepatic impairment
Manufacturer advises caution in mild to moderate impairment; avoid in severe or acute impairment, acute hepatitis, or hepatic failure. Dose adjustments Manufacturer advises consider dose adjustment in mild to moderate impairment.
Renal impairment
Caution in mild to moderate impairment; avoid in severe impairment. M Dose adjustments Consider dose adjustment in mild to moderate impairment. M
Medicinal forms
Capsule
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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