The most important long-term effect of methadone is usually the reduced craving for drugs such as heroin and morphine. Unfortunately, however, some of the long-term effects of methadone are far less pleasant. For example, a person may experience respiratory problems, such as inadequate respiration, when taking this drug for an extended period of time. Likewise, some people experience sexual changes and hormonal imbalances that are related to methadone use. Addiction is also among the long-term effects of methadone use, and people may suffer withdrawal symptoms when they stop taking it.
One of the long-term effects of methadone is its ability to help people fight drug additions. This drug is often used to help people overcome cravings for other drugs that are categorized as opiates, which are narcotics derived from opium. In order for this effect to be successful, a doctor usually prescribes a gradually increasing dose of methadone and carefully monitors the patient’s responses to it, and eventually, the dose is stabilized. This method of gradual introduction to higher doses of methadone is used to prevent or minimize side effects of the drug. For example, this gradual increase may help reduce the likelihood the drug will have a sedative-like effect on the patient; cause nausea, vomiting, or constipation; or affect the patient's brain function.
Most people who take methadone don’t experience serious health problems. In some cases, however, a person who takes this medication for a long period of time will experience problems that are related to the respiratory system. This drug may also cause hormonal changes in some patients. For example, it is sometimes associated with the reduced production of the hormone testosterone. Some women who take it may have altered menstrual cycles as well.
In some people, the long-term effects of methadone include those that are related to sexual function. Some people may experience a noticeably decreased desire for sex when they are taking it. Others may experience physical problems that prevent them from enjoying satisfactory sexual intercourse. For example, a man may become impotent as a result of methadone treatment. Such problems do not affect every person who takes this drug, however, and such side effects may depend on the dosage the individual takes.
Addiction is also among the long-term effects of methadone use. Though methadone is used to reduce an addict's cravings for other drugs, it is also addictive. If a person attempts to stop taking methadone after a long period of use, he is likely to suffer from withdrawal symptoms. Among these symptoms are nausea and vomiting, chills, drug cravings, and muscle cramps.
An individual may also experience excessive sweating and chills as a symptom of methadone withdrawal. Though these symptoms are unpleasant, they tend to be less severe than those one might suffer when withdrawing from drugs such as heroin. Additionally, gradually weaning the patient off methadone may help minimize withdrawal side effects.