Therapeutic Classification: alcohol abuse therapy adjuncts
Pharmacologic Classification: opioid antagonists
Absorption: Well absorbed orally, but undergoes extensive first pass hepatic metabolism resulting in 5–40% bioavailability. Well absorbed following IM administration.
Distribution: Enters breast milk.
Half-Life: Oral: Naltrexone—4 hr; 6-beta-naltrexol—13 hr; IM: Naltrexone—5–10 days; 6-beta-naltrexol—5–10 days.
(opioid blockade)
| ROUTE | ONSET | PEAK | DURATION |
|---|---|---|---|
| 50 mg PO | 5 min–1 hr‡ | unknown | 24 hr‡ |
| 100 mg PO | 5 min–1 hr‡ | unknown | 48 hr‡ |
| 150 mg PO | 5 min–1 hr‡ | unknown | 72 hr‡ |
| IM | unknown | unknown | 4 wk |
‡Determined by blockade of effects of 25 mg heroin IV.
Contraindicated in:
Use Cautiously in:
CV: palpitations
Derm: rash
EENT: hoarseness, runny/stuffy nose, sinus problems, sneezing
GI: abdominal cramps/pain, nausea, constipation, ↓appetite, diarrhea, HEPATOTOXICITY, vomiting
GU: delayed ejaculation, erectile dysfunction
Hemat: eosinophilia, thrombocytopenia
Local: injection site reactions
MS: muscle/joint pain
Neuro: anxiety, fatigue, headache, insomnia, nervousness, depression, dizziness, ↑energy, sedation, SUICIDAL IDEATION
Resp: EOSINOPHILIC PNEUMONIA (INJECTION), cough
Misc: chills, ↑thirst
Drug-drug:
Opioid Dependence
Alcohol Dependence
Lab Test Considerations:
NDC Code