Opiate withdrawal symptoms can last several weeks, depending on a patient's general health, type of opiate, severity of addiction and last drug use, states MedlinePlus. The initial treatment week is the most difficult. Symptoms begin about 12 hours after last using heroin and about 30 hours after last using methadone.
Opiate withdrawal symptoms occur in stages, and early-stage symptoms include irritability, muscle pain, anxiety, insomnia and sweating, notes MedlinePlus. As the withdrawal progresses, these symptoms may become more severe, and patients may experience additional symptoms such as nausea, vomiting, stomach aches and diarrhea. Doctors may administer medications such as clonidine hydrochloride or naloxone to minimize common symptoms, or naltrexone to treat an overdose of heroin.