Methadone: Side Effects
Share on Share on Share on

Methadone Side Effects

Methadone side effects encompass a wide range of symptoms. The most common ones include: constipation, drowsiness, dry mouth, euphoria, lightheadedness, slow or troubled breathing, urinary retention, and weakness. More uncommon methadone side effects include: allergic reactions, blurred or double vision, confusion, depression, dizziness, facial flushing, headache, heart palpitation, hives, impaired concentration, itching, nausea, sensation of drunkenness, skin rash, sweating, and vomiting. Additional methadone side effects may include: anaphylactic reactions, disorientation, hallucination, hypotension causing weakness and fainting, kidney failure, muscle twitching, myasthenia gravis, seizures, tremor, and an unstable gait.

What is methadone?

Methadone is a (synthetic opiate) narcotic. People addicted to heroin or other opiates will often take this medication to suppress their cravings and withdrawal symptoms. However, patients become as physically dependent on methadone as they were to heroin or other opiates (such as OxyContin or Vicodin).

Methadone maintenance is not a cure for opiate addiction. Truly, the addict is replacing one drug addiction for another. An accurate way of looking at methadone maintenance is “one person’s methadone maintenance dose is another's poison.” A regular user of opiates develops a certain tolerance. Therefore, it is possible that a tolerant person to methadone side effects can function normally with dosages which can be fatal to a non-tolerant person.

When this drug is used during pregnancy the methadone side effects cross the placenta to the unborn child. Many of the babies born to methadone-dependent mothers go through withdrawal at birth. Their symptoms vary in length and severity and can be successfully treated while the baby is still in the hospital. Also, small amounts of methadone may be passed on through breast milk. This is why mothers that are on a methadone program are often encouraged to breastfeed in order to help ease the baby's withdrawal from methadone. Although we do not encourage methadone use, women using methadone have fewer problems during their pregnancy than those who continue to use heroin. This is probably due to careful monitoring of the mother during her pregnancy and special attention to her prenatal care.

Over the years, many people have died due to methadone side effects and overdose. Before the late 1990s, methadone was used mostly to treat heroin addiction. The number of deaths attributed to methadone overdose in 1999 was 786. But by 2005, methadone-related overdose deaths had risen to 4,462. Taking an overdose of methadone is a serious medical emergency. In the event of suspected methadone overdose, call an ambulance. If the person is losing consciousness, maneuver them onto their side in the recovery position so that they will not choke if they vomit. Inducing people to vomit is not recommended because of the risk of rapid onset CNS depression/unconsciousness which could lead to choking.

Methadone is one of the strongest opiates. It has a slow onset of action and a long half-life and causes severe methadone side effects such as respiratory depression which is usually the cause of death.

Common Methadone Side Effects:

  • abdominal cramps
  • aching muscles and joints
  • back and joint aches
  • below normal drop in body temperature
  • constipation
  • cravings for the drug
  • diarrhea
  • difficulty sleeping 
  • dizziness
  • drowsiness/nodding off
  • feeling physically weak
  • fluid retention
  • goose bumps
  • heart palpitations
  • high temperature but feeling cold
  • irregular periods
  • irritability/aggression/feelings of uneasiness
  • loss of appetite
  • lowered sex drive
  • muscle spasm and jerking
  • nausea/vomiting
  • pinpoint pupils
  • poor blood circulation
  • problems with sexual functioning 
  • runny nose, sneezing
  • sedation
  • shallow breathing
  • skin rashes and itching
  • slow blood pulse, lowered blood pressure
  • sweating
  • tears 
  • tooth decay
  • tremors
  • yawning

Methadone: Side Effects
Drug of Choice:
Looking for Treatment?:
Describe the situation: