The Effects of Methadone: The Lesser-Known Perils of a Cure

Last Updated: June 24, 2020

Authored by Olivier George, Ph.D.

Reviewed by Michael Espelin APRN

Although indicated in the treatment of chronic pain and recovery from opioid addiction, methadone poses some risks to the body. This is because the prescription drug causes some side effects, which can be both short and long term.

The effects of methadone on the body vary in severity. Some of these can be mild and can be attended to by a doctor in due time. However, other side effects are very severe and need emergency medical attention. So, can methadone kill? It definitely can if you don’t seek the required professional medical intervention.

To prevent experiencing the methadone side effects, there are some precautions that a patient needs to adhere to. Read on to find out more about the methadone effects and how they can be avoided or treated.

Short Term Side Effects

Even though the drug has some positive and beneficial uses, there are some methadone adverse effects when it is used. Some of the dangers of methadone can appear as soon as a person starts taking the medication, and they can last a short time.

These short term effects of methadone include:

  • Dizziness
  • Stomach upsets
  • Constipation
  • Urinary retention; an inability to properly pass urine
  • Dry mouth
  • Skin lesions which is one of the signs of methadone use in syrup or liquid form
  • A feeling of lightheadedness
  • Slight tremors across the body
  • Irregular heartbeat due to methadone qt prolongation
  • Seizures
  • Confusion and hallucinations
  • Respiratory problems like shallow breathing
  • Lethargy; a sense of being tired and lazy all the time

girl sleeping on a sofa

These methadone treatment side effects can be reported early to the doctor to get relief so that the patient can continue using the medication to get the benefits that it offers.

Long Term Side Effects

Some of the side effects of methadone treatment do not show up early when a patient is taking the medication. Instead, they build up over time and affect the person over a long time.

Here is what the use of methadone 40 mg can do to the body in the long run.

Physical Long Term Side Effects

Some long term effects of methadone use affect the body physically. This means that they can be seen and felt by the person and detected by the doctor through physical examination.

These physical side effects of long term methadone use include:

Psychological Long Term Effects

Apart from the physical effects that affect patients during the use of the drug, there are other long term effects of methadone that affect the psyche.

  • Being an opioid drug, the medication increases impulsivity and risky behavior.
  • Pregnant mothers on the drug can have babies born addicted to methadone.
  • Anxiety
  • Depression
  • Irritability
  • Addiction if the drug is abused
  • Withdrawal symptoms when the medication is suddenly halted

irritable man

How Methadone Affects The Brain

The drug similarly affects the brain, like the more potent opioid agents whose addiction a person is trying to recover from. What sets this drug apart from the addictive ones is the fact that it stays longer in the body. How long does methadone last in the system? It persists for about 1 to 2 days.

Because this medication is less potent than addictive drugs, patients might abuse it for long to elicit the same response as the addictive narcotics like morphine and heroin. This can cause long term effects of methadone on the brain.

Which Variables Determine The Emergence Of Side Effects?

The side effects of methadone vary according to some common factors. According to research findings published in the Journal of General Internal Medicine, there are risk factors that can enhance the way adverse effects of the drug present in patients.

doctor talking to patient

Examples of these variables include:

  • Age. As someone ages, they experience side effects differently. In this case, the liver – which metabolizes this medication – might not function adequately in older patients, increasing adverse reactions.
  • Dosage. Methadone 10 mg side effects might be less than those of 40 mg of the drug.
  • Type of treatment the patient is undergoing. For example, those who receive the drug for pain management usually experience respiratory problems, whereas those undergoing maintenance therapy rarely do.
  • Types of intake. The administration of liquid medication is more likely to result in skin lesions compared to taking the tablet.
  • Individual tolerance. Some people are naturally capable of not experiencing any side effects of methadone or just a few.
  • Electrolyte abnormalities. Patients with this condition are more likely to get methadone QTC prolongation – heart arrhythmia.
  • Malnourishment
  • Sex. A patient’s sex can determine the kind of adverse reactions experienced. For example, men experience erectile dysfunction, whereas women get menstrual problems.

Precautions To Prevent Side Effects

This is beneficial in helping to steer clear of some short and longterm effects of methadone.

These are the special precautions that need to be taken to safely use the drug.

  • The patient needs to inform the doctor of any drugs or supplements they are on to prevent interactions. For example, methadone and suboxone do the same thing and can, therefore, cause augmented side effects.
  • Additionally, a patient needs to disclose any herbal products they are taking since they might also be methadone contraindications.
  • The doctor also needs to know if a patient gets an allergic reaction to methadone.
  • Patients should inform dentists that they are taking this medication.
  • Doctors also need to be aware of patients’ prevailing medical conditions like seizures, trouble urinating, liver disease, kidney disease, and enlarged prostate glands, among others.
  • Breastfeeding mothers need to alert doctors before taking the drug to prevent it from passing through the milk to the baby.

Getting Help To Cope With Methadone Side Effects

Patients need to get help for the side effects of methadone. This is so that they can continue to benefit from the positives the medication has to offer.

Since it is opioid, working-class patients might also worry about failing drug tests at work, increasing their anxiety. What does methadone show up as on a drug test? It doesn’t show up on a regular inspection that tests for addictive narcotics.

With that in mind, a patient can take methadone for their chronic pain or opioid addiction without any worries or aggravation of the anxiety.

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Published on: August 3rd, 2016

Updated on: June 24th, 2020

About Author

Olivier George, Ph.D.

Olivier George is a medical writer and head manager of the rehab center in California. He spends a lot of time in collecting and analyzing the traditional approaches for substance abuse treatment and assessing their efficiency.

Medically Reviewed by

Michael Espelin APRN

8 years of nursing experience in wide variety of behavioral and addition settings that include adult inpatient and outpatient mental health services with substance use disorders, and geriatric long-term care and hospice care.  He has a particular interest in psychopharmacology, nutritional psychiatry, and alternative treatment options involving particular vitamins, dietary supplements, and administering auricular acupuncture.


Leave a comment

  • Alicia Kenerley
    While I do not like having to rely on medicine my pain levels are too high to function without it, I am fortunate in that i do not get any euphoria at all from taking methadone, it just helps my pain become a little tolerable.. I have taken 5-10 mgs./day for over 10 years and I do not know of another medicine to switch to that wouldn’t have the same side effects of the respiratory issues. My doctor always checks my feet, he has never, ever once listened to my bretahing and that alone concerns me.
  • Joe
    I take methadone there is no euphoria there is a blocker in it so u cant feel high it just takes away pain .for me i got alot of other probs from takeing it thoughi now have epileptic seizures i am 33 never had them untill i took mdone for about 3 yrs now i got breatheing issues urinateing issues the seizures by far are the worst it happens just about every day and they last for hrs
  • Sam
    I notice after over a year of taking methadone…and quiting smoking for breathing is labouring now..I do believe it’s the methadone. Do we get better or not?
    • Joe
      No we don’t get better. 14 years & I still am married to it. I hate it but need it. Tried to wean off it but that was a disaster. Good luck Sam. To us all.
      • Yvette
        Hi Joe I was on methadone for 10 yrs. They detoxed me from 128mg to 3mg in 21 days. It was he’ll but I made it. I’ll be celebrating 7 yrs this Aug. You can do it take your time.
      • Amal
        You have to detox slowly off of it. It is possible. I went from 150 mg to 10mg and I left and i lowered my dose every 2 weeks because I had a once every 2 week scheduled. Now i dont have to deal with these bastards. I had cancer and i had a dr telling me i was not allowed pain relief after surgery. Even though it was illegal. I was threatened to have my schedule taken away if I took one legal prescription pain pill and threatened with a discharge. All because I made an OASAS complaint where there is no patient advocacy against the dr. With a clinic you have no life, you can’t go on vacation out of the country, take your bottles on a plane, you have to beg them to get time off. Im done doing that. If you go slowly it wont be a disaster. You could do it.
  • Jay
    Everything stated in this article is 100% accurate. I was on methodone for 6 years and was rapidly detoxed. I have developed hypothyroidism and hypogonadotropic hypogonadism from the effects it had on the endocrine system. Recently diagnosed with sleep apnea and have severely high and dangerous treatment resistant depression. Despite my treatment for sleep apnea, hypogonadism, hypothyroidism and blood pressure I remain very sick. My doctor suggested putting me on Suboxone but I want my body to recover besides I’m not sure it would be safe since it would effect my testosterone and sleep apnea. Why do I remain very sick all the time? I wake up in the morning to my hands being red and numb. Despite 3 blood pressure medications my BP is still very high and skyrockets at the drop of a hate. I struggle to breathe during the day. I desperately need help because I can’t handle these symptoms. Despite sobriety I still throw up some mournings. Could I have permanent respitory problems and automatic nervous system malfunction? I need answers and not many doctors know anything about the long-term effects methadone has on the body. I’m not crying for help when I say this but my symtoms are so unbearable I think about suicide 24/7. Sleep study said evidence of upper airway resistant. I need to know what areas I should focus on to get better. My blood pressure is slowly killing me. What if any treatments are out there if I have permanent automatic nervous system malfunction? I’m desperate
    • Clifford G Copeland
      When I read your message it sounded like you were talking about me a lot of the same symptoms same medication do the same problems depression is crazy I am laying off this s*** wish me luck