Nalmefene

First approved for Opioid Overdose in U.S. as of 1995, but was discontinued by manufacturer in U.S. in 2006
Has been used in Europe for Alcohol Abuse (similar to Naltrexone)

Long acting opioid Antagonist
Duration
1. IV: 4-8 hours
2. Intranasal: 6 hours
  1. Contrast with 2 hours for intranasal Naloxone
Plasma Half-Life up to 11 hours (contrast with 2 hours for Naloxone)
1. Mildly decreased clearance in elderly or liver or Kidney disease
Bioavailability
1. Intranasal: 80%
2. IM or SQ: 100%
Onset
1. IV 2 to 5 minutes
2. IM: 5 to 15 minutes (peak effect 2 to 3 hours)
3. SQ: 5 to 15 minutes (peak effect 1.5 hours)
4. Intranasal (Opvee): 2.5 to 5 minutes (peak effect 15 minutes, up to 3 hours)

Opioid Overdose
1. Initial: 0.5 mg per 70 kg person IV
2. Later: 1 mg per 70 kg IV prn 5 min after initial dose
3. Opioid dependent: 0.1 mg per 70 kg test dose
Post-operative Opioid reversal
1. Dose: 0.25 ug/kg IV q2-5 minutes
2. Maximum: 1 ug/kg total dose

Serious
1. Severe and prolonged Opioid Withdrawal
Common (general)
1. Headache
2. Nausea
3. Vomiting
4. Dizziness
5. Hot Flushes or diaphoresis
6. Fatigue
7. Anxiety
Common (nasal Inhaler)
1. Nasal discomfort, nasal congestion, Rhinorrhea
2. Throat irritation