Precautions

Drug information provided by: Merative, Micromedex®

The effects of the opioid medicine may last longer than the effects of the nalmefene. This means the breathing problems and sleepiness could come back. Always call for emergency help after the first dose of nalmefene.

Severe opioid withdrawal symptoms may happen suddenly after receiving this medicine. These include body aches, a fever, sweating, runny nose, sneezing, goose bumps, yawning, weakness, shivering or trembling, nervousness, restlessness or irritability, diarrhea, nausea or vomiting, stomach cramps, fast heartbeat, and increased blood pressure.

Nalmefene injection may not be able to completely reverse the opioid effects (eg, respiratory depression) of buprenorphine and pentazocine. Repeated doses of nalmefene may be needed to reverse the opioid effects.