Side Effects of Methadone: A Detailed Look

Methadone, a medication widely prescribed to manage opioid addiction, serves as an essential tool in harm reduction. Its primary purpose is to lessen withdrawal symptoms and cravings, providing a stable foundation for individuals on the path to recovery.

However, despite its efficacy in addiction treatment, methadone is not without its side effects. Read on as we provide a comprehensive understanding of what individuals might expect when using methadone as part of their recovery program.

Key Takeaways

Methadone is a prescription drug administered in special care clinics and comes with various side effects. Here is what you need to know:

  • Methadone, a long-acting opioid, helps manage withdrawal symptoms and drug cravings, supporting individuals in recovery.
  • Like any medication, methadone may have side effects ranging from mild to severe, requiring proactive management.
  • Proper management of side effects involves adherence to the prescribed methadone dose and regular monitoring by doctors.

Contact The Recovery Team today at (800) 817-1247 to explore our medical treatment options for lasting recovery from substance use disorder (SUD).

What is Methadone?

Methadone is a synthetic opioid medication primarily known for its use in managing opioid use disorder (OUD) and pain relief. It belongs to the class of drugs called opioids, acting on the same receptors in the brain as other opioid drugs like heroin and morphine.

Opioid Addiction Treatment

Methadone is used as a part of a treatment program known as medication-assisted treatment for opioid dependence. Methadone helps reduce withdrawal symptoms and cravings, enabling individuals to taper off opioids and stabilize their lives gradually.

Pain Management

Methadone is also used for chronic pain when other pain medications aren’t effective. Its unique properties, including its long-lasting analgesic effects, make it valuable in managing severe pain, especially in cases where other opioids may not be as effective.

Despite its medical uses, methadone carries a high risk of addiction, methadone overdose, and unwanted side effects. Therefore, proper administration and monitoring by healthcare professionals are crucial to ensure its safe and effective use in managing drug abuse and pain.

Digestive System Side Effects of Methadone

Methadone can bring about various effects on the digestive system, including:

Nausea and Vomiting

One common side effect of methadone is feeling nauseous, which may lead to vomiting. This queasy sensation in your stomach can make eating or enjoying meals challenging, affecting your daily routine.


Another prevalent issue is constipation. Methadone can slow down the movement of your bowels, making it harder to have regular and comfortable bowel movements. This might cause discomfort and require additional measures to ease.

Dry Mouth

Methadone can also make your mouth feel dry. This dryness can be bothersome and might increase the risk of dental issues if not appropriately managed.

Loss of Appetite

Some individuals in methadone therapy might experience a reduced desire to eat. This decrease in appetite can affect your nutrition and energy levels.

Abdominal Pain

Abdominal discomfort or pain is another possible effect of methadone on the digestive system. This pain can range from mild to severe and may require medical attention if persistent.

Cardiovascular Side Effects of Methadone

Methadone can have impacts on the cardiovascular system, leading to various side effects. Some of these include:

Irregular Heartbeat

Methadone medication can sometimes cause abnormalities in the heart’s rhythm, leading to irregular heartbeats.

Low Blood Pressure

Methadone may cause a drop in blood pressure, potentially leading to extreme dizziness or fainting, especially when standing up quickly.

Slower Heart Rate

Methadone can reduce the heart rate, which might not pose a problem for everyone but can be concerning for those with pre-existing heart conditions.

Heart Attacks

Although less common, methadone has been associated with an increased risk of heart attacks or other cardiovascular issues in certain individuals, particularly those with pre-existing heart conditions or those taking higher doses.

Respiratory System Side Effects of Methadone

Methadone, like other opioids, can impact the respiratory system in various ways, potentially leading to:

Shallow Breathing

Methadone, as an opioid, can depress the respiratory system, slowing down breathing and sometimes causing it to become dangerously shallow, especially at high doses.

Respiratory Distress

In some cases, individuals may experience trouble breathing or respiratory distress, particularly if they’re sensitive to opioids or if they’re taking a high dosage of methadone.

Cough Suppression

Opioids, including methadone, can suppress the cough reflex, which might be a concern for individuals needing to clear their airways due to illness or infection.

Respiratory Infections

There’s an increased risk of respiratory infections in individuals taking methadone, as the drug’s effects on the respiratory system might make them more susceptible to infections.


Some individuals may experience bronchospasm—a sudden constriction of the muscles in the walls of the bronchioles—leading to breathing problems.

Neurological Side Effects of Methadone

Methadone affects the neurological system and may cause various neurological side effects in some individuals, such as:

Drowsiness or Sedation

One of the expected effects of methadone is central nervous system depression, which can lead to drowsiness or a feeling of sedation.

Dizziness or Vertigo

Some people may experience feelings of dizziness or vertigo while taking methadone, especially when standing up quickly or changing positions.


Headaches can occur as a side effect of long-term methadone use, although they might not affect everyone using the medication.


Methadone can sometimes cause confusion, particularly in higher doses or in individuals who are more sensitive to its effects.

Cognitive Impairment

Opioids like methadone might impair cognitive function in some individuals, affecting attention, memory, and decision-making abilities.


Although relatively rare, in certain cases, methadone can lower the seizure threshold, potentially leading to seizures, especially in those with a history of seizures or epilepsy.

Psychological Side Effects of Methadone

Methadone can impact psychological well-being, leading to various psychological side effects:

Mood Changes

Methadone can affect mood, causing fluctuations in emotions or mood swings in some individuals.

Depression and Anxiety

Some people may experience mental health problems, such as feelings of depression or increased anxiety while taking methadone.

Sleep Disturbances

Changes in sleep patterns can occur as a side effect of methadone. This may include difficulty falling asleep or staying asleep.

Psychomotor Impairment

Methadone can impair psychomotor skills, affecting coordination, reaction time, and overall motor functions.

Dependency and Addiction

Being an opioid, methadone carries a risk of physical dependence and, in some cases, methadone addiction if not used as prescribed or when used recreationally.

Withdrawal Symptoms

Abruptly stopping methadone can lead to withdrawal symptoms, which can be intense and uncomfortable. This emphasizes the importance of tapering off the medication under medical supervision to minimize withdrawal effects.

Sexual and Reproductive Side Effects of Methadone

Methadone impacts sexual and reproductive functions in various ways, leading to potential side effects such as:

Decreased Libido

Some individuals may experience a decrease in sexual desire or interest while taking methadone.

Erectile Dysfunction (ED)

Methadone abuse can contribute to difficulties in achieving or maintaining an erection in males.

Orgasmic Dysfunction

Both men and women may experience difficulties reaching orgasm or experiencing a satisfying sexual climax while using methadone.

Menstrual Irregularities

In some cases, methadone can cause changes in menstrual patterns, such as irregular periods or changes in menstrual flow, in women.

Hormonal Changes

Opioids, including methadone, can affect hormone levels, which may contribute to various reproductive and sexual side effects.

Methadone Side Effects when Pregnant

Undergoing methadone maintenance treatment during pregnancy can present risks and considerations for both the mother and the baby:

Risks for Mother

For pregnant women on methadone, there can be heightened risks, including an increased likelihood of medical problems during pregnancy. These problems might involve a higher chance of preeclampsia, gestational diabetes, or difficulties in labor and delivery.

Risks for Baby

The use of methadone during pregnancy can also pose risks to the baby. It may lead to neonatal abstinence syndrome (NAS), where the baby experiences withdrawal symptoms after birth. NAS can manifest as difficulties feeding, irritability, tremors, and other withdrawal signs. Additionally, there might be a risk of preterm birth or low birth weight.

Side Effects of Mixing Methadone with Other Substances

Mixing methadone with other substances can be extremely dangerous and may result in various side effects or complications. Here are some specific drug interactions and their potential side effects:


Combining methadone with alcohol can intensify central nervous system depression, leading to extreme drowsiness, breathing difficulties, loss of consciousness, or even overdose. Both substances slow down the respiratory system, increasing the risk of respiratory failure.


Combining methadone with benzos can heighten sedation, respiratory depression, and the risk of overdose. This combination significantly increases the likelihood of slowed breathing and can be life-threatening.

Other Opioids

Mixing methadone with other opioids, including prescription painkillers or illicit drugs like heroin, increases the risk of opioid overdose and severe respiratory depression. It can also heighten the potential for drug addiction or dependence.


Combining methadone with stimulants can create a paradoxical effect where the stimulant may mask the sedative effects of methadone. This can increase the risk of unintentional overdose or cardiac complications due to the combined impact on the heart and cardiovascular system.

Marijuana or Cannabis

While the interactions may not be as severe as with some other substances, combining marijuana with methadone can amplify the sedative effects, leading to increased drowsiness, confusion, or impaired motor skills.

Tips to Manage Side Effects of Methadone

Managing side effects from medications like methadone often involves a combination of strategies. Here are some tips to help manage the side effects when undergoing methadone maintenance therapy (MMT):

Communication with Healthcare Provider

Keep an open line of communication with your healthcare provider. Discuss any side effects experienced, their severity, and how they impact your daily life. This allows for appropriate adjustments in dosage or potential alternative medications.

Follow the Prescribed Methadone Dosage

Adhere strictly to the prescribed dosage. Changes in the dose of methadone should only be made under the guidance of a healthcare professional. Abruptly stopping or changing doses without medical care can lead to life-threatening withdrawal symptoms or other complications.

Regular Monitoring

For those on methadone treatment, regular monitoring by healthcare providers is crucial for safety. Doctors assess the medication’s effectiveness, manage side effects, and ensure overall well-being.

Lifestyle Modifications

Making lifestyle changes can help alleviate some side effects of methadone withdrawal. This may include dietary adjustments, regular exercise, stress management techniques, and adequate sleep.

Support Groups or Counseling

Joining support groups or seeking counseling can be beneficial, especially for those dealing with psychological side effects or struggling with the emotional aspects of substance abuse.

Careful Medication Management

Avoid combining methadone with other substances, including alcohol or other medications, without consulting your healthcare provider.

Live Beyond Addiction with The Recovery Team

Struggling with methadone addiction can feel overwhelming, but remember: you’re not alone, and there’s hope for a brighter future. At The Recovery Team, we’re here to guide you every step toward a life free from addiction.

Our tailored residential and outpatient care programs fit your unique needs. Evidence-based therapies like cognitive-behavioral therapy (CBT), medication management, engaging activities, and family involvement form the pillars of our addiction treatment plan.

Don’t wait another day to start your journey to freedom from addiction. Call our treatment team at (800) 817-1247 for more information.