Myoclonus is a sudden muscle jerk that happens unexpectedly. It can be because of certain medicines. We will talk about drugs that can trigger myoclonus, how it happens, who is more at risk, how to diagnose and treat it, and what life is like with it.

Myoclonus is a movement disorder where muscles jerk without us wanting them to. This can be in one area, several areas, or all over the body. It happens due to a fast muscle tightening (positive myoclonus) or a quick stop in muscle movement (negative myoclonus).

If you’re facing sleep myoclonus, looking for myoclonus treatment, or just want to understand the symptoms of myoclonus, we’ve got you covered. This article has all the info you need about this condition.

Understanding Myoclonus

Myoclonus is a disorder that makes your muscles jerk quickly and without warning. These jerks can happen in just one muscle, a few muscles, or all over your body. They happen because your muscles either suddenly tighten up or relax.

What is Myoclonus?

Myoclonus is when your muscles suddenly contract and relax. These jerks can range from small twitches to big, disruptive movements. It can be caused by many things like brain problems, changes in your body’s metabolism, or certain drugs.

Types of Myoclonus

There are different kinds of myoclonus, each with its unique signs and reasons:

  • Cortical myoclonus: Comes from the brain’s outer layer and mostly affects the hands and face.
  • Subcortical myoclonus: Starts between the brain’s outer layer and the spinal cord. It includes types like brainstem myoclonus and palatal myoclonus.
  • Essential myoclonus: Shows as muscle jerks without any other signs.
  • Stimulus-sensitive myoclonus: Jerks that get triggered by sudden movements, loud sounds, or bright lights.
  • Sleep myoclonus: Muscle jerks while falling asleep or during sleep.

Symptoms of Myoclonus

The main symptom is the sudden muscle jerks or twitches. They can affect just one muscle or many at once. They might happen all of a sudden and can be set off by certain movements or things like light and noise.

Also, people with myoclonus might feel like their muscles are trembling or twitching even when they’re not moving.

Drugs That Cause Myoclonus

Antiepileptic Drugs

Some antiepileptic drugs can cause myoclonus. This is a twitching or jerking of a muscle. Examples include:

  • Carbamazepine: May cause negative myoclonus with drugs like clobazam.
  • Lamotrigine: Can make myoclonus worse or start it in some epilepsy patients.
  • Pregabalin: Linked to myoclonus in epilepsy patients taking it as an extra medicine.


Various antidepressants can lead to myoclonus. This includes:

  • Clomipramine and maprotiline, which are tricyclic antidepressants.
  • Sertraline, a selective serotonin reuptake inhibitor (SSRI).
  • Venlafaxine, a serotonin-norepinephrine reuptake inhibitor (SNRI).


Both typical and atypical antipsychotics can cause myoclonus. Some examples are:

  • Haloperidol
  • Clozapine
  • The misuse of Quetiapine


Opioid drugs are also linked to myoclonus. This is especially notable with:

  • Fentanyl, which can cause it during withdrawal
  • Tramadol
  • Methadone

drugs causing myoclonus

Mechanisms Behind Drug-Induced Myoclonus

The reasons why some drugs cause myoclonus are not fully clear. But, we do have some ideas. These include problems with certain brain chemicals like gamma-aminobutyric acid (GABA) and serotonin.

Drugs used to treat epilepsy, for instance valproate, can lead to negative myoclonus. This happens when someone is nearly unconscious from the drug. With tests, doctors found this type of myoclonus does not come from epilepsy itself (Aguglia U et al., 1995).

Plus, drugs for depression like tricyclic antidepressants and SSRIs can also cause myoclonic jerks. Experts think this is because these drugs mess with serotonin levels in the brain (Casas M et al., 1987; Alonso-Navarro H et al., 2006).

Antipsychotic and pain-relief drugs have been blamed for myoclonus too. The reasons are not totally clear. But, scientists think these drugs might harm the brain’s dopamine system. Or, they may trigger too much excitement in nerve cells or too much stress on cells (Barak Y et al., 1996; Dib EG et al., 2004; Dominguez C et al., 2009).

Remember that we’re still learning about how some drugs spark myoclonus. More studies are needed to figure out the exact ways they do this (Brefel-Courbon C et al., 2006).

Risk Factors for Drug-Induced Myoclonus

Several factors can up the risk of drug-induced myoclonus. This condition makes muscles jerk or twitch without control. Knowing these risks helps doctors spot and handle this side effect of some drugs.


Older folks tend to face higher chances of drug-induced myoclonus. This is often because the body’s way of handling drugs changes with age. Also, older people take more meds and have more health issues.

Underlying Medical Conditions

Some health problems can make myoclonus more likely. These include epilepsy, Parkinson’s, and issues with the kidneys or liver. Problems with electrolytes can also play a role.

Drug Interactions

Using certain drugs together can increase the risk. For instance, combining antidepressants with lithium, or epilepsy drugs with CNS depressants, can up your chances. The same goes for mixing antibiotics with antipsychotics.

risk factors for drug-induced myoclonus

Diagnosis of Drug-Induced Myoclonus

Diagnosing drug-induced myoclonus starts with a detailed medical history. This includes when the muscle jerks started and what they’re like. Your current and past medications are also checked, as well as any existing health problems. The doctor will then do a physical exam. They’ll look at how the jerks are distributed and what may set them off. They’ll also check neurological functions like reflexes, and for other movement issues or damage.

Medical History

Your medical history is key to finding out what’s causing the myoclonus. Doctors will ask about when the jerks began and their characteristics. They’ll also look into the medications you’re taking now or have taken before. This includes checking for any health issues that might be linked to the myoclonus.

Physical Examination

During the exam, the healthcare provider looks at how the muscle jerks are spread around your body. They aim to find what makes them happen. They’ll test your reflexes and other neurological functions. This is to see if there are other movement or nerve problems.

Diagnostic Tests

To get a clear diagnosis, more tests might be needed. Some of these could be an EEG, which looks at brain wave patterns. An EMG may also be done to study the muscle activity. And there could be blood tests to check for metabolic or toxic issues.

Managing Drug-Induced Myoclonus

Dealing with drug-induced myoclonus needs a mix of steps. The goal is to lessen muscle jerks and twitches. Start by making sure the medicine dose is right.

Adjusting Medication Dosages

To fight myoclonus, cutting back on the medicine might work. It’s done slowly to avoid bad effects after stopping the medicine.

Switching Medications

If lowering the medicine dose doesn’t help, your doctor might suggest trying another drug. They could pick a new medicine or a different treatment to cut myoclonus risks.

Treating Underlying Conditions

If an illness causes myoclonus, treating that illness can help. This might mean changing epilepsy or Parkinson’s drugs. Or fixing issues like not well-functioning body organs.

Drugs That Cause Myoclonus: What You Need to Know

Various medications have been tied to causing myoclonus as a side effect. The drug groups often involved are:

  1. Antiepileptic Drugs: Medicines for epilepsy, like carbamazepine, lamotrigine, and pregabalin, can lead to myoclonus. The mix of carbamazepine and clobazam can result in negative myoclonus. Meanwhile, lamotrigine might worsen or trigger myoclonus in those with epilepsy.
  2. Antidepressants: Myoclonus can be seen with tricyclic antidepressants such as clomipramine, SSRIs like sertraline, and SNRIs including venlafaxine.
  3. Antipsychotics: Both typical and atypical antipsychotic drugs could cause myoclonus. Haloperidol, clozapine, and quetiapine (if misused) are often linked to myoclonus cases.
  4. Opioids: Opioid drugs, especially fentanyl during withdrawal, tramadol, and methadone, are known to cause myoclonus.

Many other drugs, such as antibiotics and Parkinson’s disease medications, can also induce myoclonus. This shows how broad the list of possible culprits is.

Preventive Measures

To prevent drug-induced myoclonus, healthcare providers should check a patient’s medication history and risks. They must watch for myoclonus symptoms when starting or changing drugs. They need to keep a close eye on at-risk patients to catch and treat myoclonus early.

Medication Monitoring

Doctors are key in stopping drug-induced myoclonus. They must go over a patient’s meds, looking at any use of specific drugs. This includes antiepileptics, antidepressants, antipsychotics, and opioids which can cause myoclonus. By watching closely, they can spot myoclonic symptoms early, and adjust meds as needed, especially for patients with other health issues.

Lifestyle Modifications

Patients can lower their myoclonus risk too. They should steer clear of triggers like sudden movements or loud sounds, which make muscle jerks worse. It’s also good to keep a regular sleep schedule and manage stress, as these factors increase the risk of myoclonus. If they see any unusual muscle movements, it’s important to tell their doctor right away.

medication monitoring

When to Seek Medical Attention

If you start having sudden, uncontrolled muscle jerks, go see a doctor fast. This is especially true if they are strong, keep happening, or make it hard to do your usual things. If you notice these along with other nerve problems like seizures, shaking, or trouble with balance, it’s urgent to get checked.

Also, if the muscle jerks begin when you start a new drug or change how much of one you take, tell your doctor. It might be the medicine causing it. Getting this checked early helps handle the issue better.

Seeing a doctor early for muscle jerks is wise. They can find what’s causing it and offer the right treatment. This is key to managing your condition well and avoiding future problems. The doctor will run some tests and then plan how to help you feel better and live well.

Living with Myoclonus

Life with myoclonus brings unique hurdles. Yet, with the right strategies and support, people can cope well. They can enjoy life to the fullest.

Coping Strategies

If you have myoclonus, try these strategies:

  • Keep a diary to note when muscle jerks happen.
  • Use meditation or deep breathing to reduce stress.
  • Avoid things that make your muscle jerks worse.
  • Talk to loved ones and doctors for support.

Support Resources

Many support options are out there for myoclonus, such as:

  1. Joining a support group, either in your area or online.
  2. Gaining knowledge from groups like the Myoclonus Research Foundation.
  3. Finding the right doctors and care providers for myoclonus.

By following these strategies and reaching out for support, managing myoclonus gets easier. This can lead to a better life quality.



Myoclonus is a movement disorder marked by sudden muscle jerks or twitches. Some medications, like antiepileptics, antidepressants, antipsychotics, and opioids, can cause it. Knowing how these drugs can induce myoclonus helps both patients and doctors deal with it.

People with myoclonus can improve their lives by working with healthcare providers. They should take preventive actions and regularly check their condition. Adjusting medications and treating other medical problems also helps a lot.

Being proactive and well-informed is crucial in handling drug-induced myoclonus. With proper care, you can manage the condition and reduce its effect on your everyday life.


What is myoclonus?

Myoclonus is when your muscles suddenly jerk or twitch without you controlling it. Things like some medicines can lead to this happening.

What are the different types of myoclonus?

There are a few types of myoclonus. This includes myoclonus that happens in the cortex, below the cortex, essential types, those that react to triggers, and also ones that happen while sleeping.

What are the symptoms of myoclonus?

The key sign is sudden muscle jerks or twitches. This may be in one muscle, several muscles, or all over the body.

What medications can cause myoclonus?

Myoclonus might happen because of some drugs. These include medicines for seizures, depression, psychosis, and strong painkillers.

How do medications trigger myoclonus?

We’re still learning about how drugs lead to myoclonus. But it could be linked to changes in some parts of the brain or how our body processes energy.

Who is at higher risk of developing drug-induced myoclonus?

Older people, those with health issues affecting the nervous system, and certain people on specific medications are more likely to get myoclonus from drugs.

How is drug-induced myoclonus diagnosed?

Doctors use a few steps to diagnose this. They gather a detailed medical history, check your body, and might do special tests like an EEG or EMG.

How is drug-induced myoclonus managed?

The first step is often to change the drug that’s causing it or the dose. Doctors also work on treating any other health problems a person might have.

How can drug-induced myoclonus be prevented?

To prevent this, doctors should always look closely at a patient’s medication history. Patients should try to stay away from things that might trigger their symptoms and keep stress low.

When should someone seek medical attention for myoclonus?

If someone has serious muscle jerks that just won’t stop, they should see a doctor. Especially if they also have other strange symptoms.

How can individuals living with myoclonus cope with the condition?

Things like writing down your symptoms, learning to relax, and finding support from others who understand can help a lot.

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