Effects of Methadone Methadone side effects can vary greatly and should be closely monitored. Symptoms that are typical of methadone users include upset stomach, headache, drowsiness, constipation, dry mouth, insomnia, decreased sexual drive and excessive sweating. Severe side effects should be reported to your doctor. These methadone side effects include becoming lightheaded, rash, hives, swelling of extremities, itching, trouble breathing and chest pain.
Overdosing on this drug can be very serious. If you or someone you know show signs of overdose, call 911 right away. These signs include include losing of consciousness, extremely dilated pupils, coma, problems breathing, clammy skin, and muscle atrophy. Stopping the drug abruptly can cause withdrawal symptoms. These symptoms are irritability, pain in the stomach, fever, nausea, excessive sweating, runny nose and eyes.
As with any addiction a person addicted to this drug will do whatever it takes to keep using the it. Some people try to deceive their doctors into believing they require a higher dosage and others take multiple dosages at one time. Many addicts will keep taking heroin while using methadone. This drug is addictive, and most people who start taking it to help stop their addiction to heroin or another opiate become addicted to the new substance. Drug tolerance and dependence will develop, resulting in the need for a detox program, which can take a lot longer to get clean than many other rehab programs.