Naltrexone

DRUG INFORMATION

  ADULT
    - The recommended dose of naltrexone for extended-release injectable suspension is
      380 mg delivered intramuscularly (deep) as a gluteal injection, every 4 weeks or
      once a month, alternating buttocks for each subsequent injection, using the carton
      components provided (2.1) .
      Source: US FDA label for naltrexone (Naltrexone), section 'dosage and
      administration', retrieved 2026-08-29
    - The recommended dose of naltrexone for extended-release injectable suspension is
      380 mg delivered intramuscularly (deep) as a gluteal injection every 4 weeks or
      once a month, alternating buttocks for each subsequent injection, using the carton
      components provided [see How Supplied/Storage and Handling ( 16 ) ] .
      Source: US FDA label for naltrexone (Naltrexone), section 'dosage and
      administration', retrieved 2026-08-29
    - Naltrexone for extended-release injectable suspension must be prepared and
      administered by a healthcare provider (2.1 , 2.6) . Prior to initiating naltrexone
      for extended-release injectable suspension, an opioid-free duration of a minimum
      of 7–10 days is recommended for patients, to avoid precipitation of opioid
      withdrawal that may be severe enough to require hospitalization (2.1) .
      Source: US FDA label for naltrexone (Naltrexone), section 'dosage and
      administration', retrieved 2026-08-29

  CHILD
    - The safety and efficacy of naltrexone for extended-release injectable suspension
      have not been established in the pediatric population. The pharmacokinetics of
      naltrexone for extended-release injectable suspension have not been evaluated in a
      pediatric population.
      Source: US FDA label for naltrexone (Naltrexone), section 'pediatric use',
      retrieved 2026-08-29
    - Naltrexone for extended-release injectable suspension must be prepared and
      administered by a healthcare provider (2.1 , 2.6) . Prior to initiating naltrexone
      for extended-release injectable suspension, an opioid-free duration of a minimum
      of 7–10 days is recommended for patients, to avoid precipitation of opioid
      withdrawal that may be severe enough to require hospitalization (2.1) .
      Source: US FDA label for naltrexone (Naltrexone), section 'dosage and
      administration', retrieved 2026-08-29

  RENAL IMPAIRMENT
    - Caution is recommended in administering naltrexone for extended-release injectable
      suspension to patients with moderate to severe renal impairment (8.6) .
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29
    - Because elderly patients are more likely to have decreased renal function, it may
      be useful to monitor renal function. 8.6 Renal Impairment Pharmacokinetics of
      naltrexone for extended-release injectable suspension are not altered in subjects
      with mild renal insufficiency (creatinine clearance of 50-80 mL/min).
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29
    - Dose adjustment is not required in patients with mild renal impairment.
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29

  HEPATIC IMPAIRMENT
    - Naltrexone for extended-release injectable suspension pharmacokinetics have not
      been evaluated in subjects with severe hepatic impairment (8.7) . 8.1 Pregnancy
      Risk Summary The available data from published case series with naltrexone for
      extended-release injectable suspension use in pregnant women are insufficient to
      identify a drug-associated risk of major birth defects, miscarriage or adverse
      maternal or fetal outcomes.
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29
    - Because naltrexone and its primary metabolite are excreted primarily in the urine,
      caution is recommended in administering naltrexone for extended-release injectable
      suspension to patients with moderate to severe renal impairment [see Clinical
      Pharmacology ( 12.3 ) ] .
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29
    - Dose adjustment is not required in subjects with mild or moderate hepatic
      impairment.
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29

  PREGNANCY
    - Risk Summary The available data from published case series with naltrexone for
      extended-release injectable suspension use in pregnant women are insufficient to
      identify a drug-associated risk of major birth defects, miscarriage or adverse
      maternal or fetal outcomes.
      Source: US FDA label for naltrexone (Naltrexone), section 'pregnancy', retrieved
      2026-08-29
    - There are clinical considerations (see Clinical Considerations ).
      Source: US FDA label for naltrexone (Naltrexone), section 'pregnancy', retrieved
      2026-08-29
    - Reproduction and developmental animal studies have not been conducted for
      naltrexone for extended-release injectable suspension.
      Source: US FDA label for naltrexone (Naltrexone), section 'pregnancy', retrieved
      2026-08-29

  BREASTFEEDING
    - Daily oral administration of naltrexone to rats and rabbits during the period of
      organogenesis did not induce malformations at doses up to 200 mg/kg/day (175- and
      14‑times the human exposure based on an AUC (0-28d) comparison, respectively). 8.2
      Lactation Risk Summary Naltrexone and its major metabolite, 6β-naltrexol, are
      present in human milk.
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29
    - There are no data on the effects on the breastfed infant or the effects on milk
      production.
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29
    - The developmental health benefits of breastfeeding should be considered along with
      the mother’s clinical need for naltrexone and any potential adverse effects on the
      breastfed infant from naltrexone or the mother’s underlying maternal condition.
      8.4 Pediatric Use The safety and efficacy of naltrexone for extended-release
      injectable suspension have not been established in the pediatric population.
      Source: US FDA label for naltrexone (Naltrexone), section 'use in specific
      populations', retrieved 2026-08-29