It's difficult to say for sure, because everyone reacts differently. Some people manage to get over their symptoms of withdrawal very quickly; others suffer a resurgence of some symptoms, such as flashbacks, for much longer. Also, while some manage to overcome the craving fairly quickly, others say they're hooked for life and the craving doesn't stop.

Heroin withdrawal

It takes about three days for heroin to be broken down and metabolised in the body, but the physical effects of withdrawal after using the drug for several years can last longer. Symptoms resulting from sudden withdrawal are likely to begin within hours of the last fix and include intense anxiety, aches, shakes, chills, stomach cramps, diarrhoea, sweating, sleeplessness, muscle spasms and excessive yawning.

Most people also experience deep and terrible feelings of depression. These symptoms may continue for a week or more.

Effective methods

It's not clear whether sudden withdrawal is the most effective way to come off drugs. If your brother simply emerges from withdrawal to rejoin the life he led before, with all of its problems and temptations, there's a good chance he'll succumb to his cravings and slip back into his old ways.

Research suggests people have the best chance of coming off drugs when they're part of a supportive multidisciplinary programme. This will provide help adjusting to a new life and learning new skills, so the person can move on and leave old friends and habits behind.

Many users find opiate substitutes such as methadone or buprenorphine can help to lessen the physical stresses of coming off heroin, reducing cravings and keeping the symptoms of withdrawal to a minimum. They can then lead a less chaotic lifestyle, reduce heroin use at their pace and adjust to life in normal society.

Drug treatments (such as lofexidine) can also help to relieve withdrawal symptoms.

Your brother's best chances probably lie with his local substance misuse team (also sometimes called the drug and alcohol action team), so ensure he and you are in touch with them to obtain the most appropriate care.

This article was last medically reviewed by Dr Trisha Macnair in March 2008