It can be an action tremor that occurs when you try to do simple tasks like picking up something or drinking from a glass. While it is not life-threatening, many patients find an essential tremor affects their quality of life. Drug-induced tremors can occur when you move your body a certain way or are in certain positions. Medications that cause the tremors include certain antipsychotics, anticonvulsants, and antidepressants. Certain medications can both cause tremors and worsen any tremors you already have from Parkinson’s disease or another similar disorder. Statistics show that MIMDs are more common in patients taking antipsychotic medications, with up to 30% of long-term users experiencing some form of movement disorder.
Table 2. Mechanisms of Medication-induced Tremor for More Common Offending Agents.
Pseudoparkinsonism, also known as drug-induced parkinsonism, is a reversible condition that resembles parkinsonism. Parkinsonism refers to any condition that causes the movement irregularities seen in Parkinson’s disease, a brain disorder. Treatment of AIMs is based on the underlying etiology (eg, metabolic, drug induced). However, symptomatic treatments are indicated to reduce motoric and psychological symptoms that impair social function and worsen quality of life. Recommended treatments for each type of AIM are summarized in Table 21,20–30 and described below.
As many as one in four people develops essential tremor as they age. You are more likely to develop essential tremor if you have a parent or sibling with the condition. Amphetamines bind and reverse the dopamine transporter (DAT) function. Consequently, they inhibit reuptake, releasing dopamine at the mesocorticolimbic dopaminergic nerve terminals. In extreme cases, it may also induce intracranial hemorrhages, comas, or seizures.
The most visually dramatic movement disorder caused by cocaine is transient chorea, also called crack dancing and buccolingual dyskinesias. According to National Center for Drug Abuse Statistics, 12.9 million Americans aged 12 years and above have abused illicit drugs at some point in their lives. A report by the National Institute on Drug Abuse revealed that in 2020, approximately 92,000 U.S citizens died from a drug-related overdose of both illegal drugs and prescription opioids. Clinicians are often faced with the task of categorizing the nature of AIMs and establishing their etiology (via a detailed history, physical/neurologic examination, and laboratory testing).
There are a number of differential diagnoses, including serotonin syndrome, and specialist assessment is required. For example, serotonin syndrome tends to occur more acutely than neuroleptic malignant syndrome. There is rigidity in neuroleptic malignant syndrome whereas myoclonus, hyperreflexia with clonus, and mydriasis are more common in serotonin syndrome. Management consists of altering the dose of, or if possible stopping, the offending drug, or switching to an alternative drug.
Amitriptyline
It is important to avoid the offending drug in the future due to the risk of a recurrent dystonic reaction. Talk to your doctor about the medications you’re taking, and consult them before adding any new over-the-counter medications. Stimulant medications and drugs containing theophylline should be used with caution. Physical therapy and occupational therapy may help people with essential tremor find easier ways to function throughout the day.
In Parkinson’s disease, there are additional changes, such as excessive sleepiness (hyposomnia) and other sleep disturbances. Other nonmotor symptoms common only in Parkinson’s disease include bowel and bladder dysfunction, as well as attention deficit. Ms A, a 23-year-old woman, was brought to the emergency department (ED) by police because of increasingly disruptive behaviors in her apartment building over the past week. She described hearing neighbors accuse her of poisoning their pets; moreover, she believed that they were “bugging” her apartment and watching her through her TV. Her medical history was notable for having systemic lupus erythematosus and chronic kidney disease. Although she had an episode of depression during college, she had not received psychiatric treatment for the past 2 years.
Medication-Induced Movement Disorders: Causes, Symptoms, and Treatments
Since treatment is predicated on etiology, a thorough approach to the problem facilitates implementation of effective treatment and minimizes adverse side effects that often accompany drug therapies. Ms A screamed loudly and made threatening gestures when the ED physician attempted to perform a physical examination. Feeling unsafe, the physician called for the assistance of hospital security officers to ensure his own safety, that of Ms A, and others in the ED. Intramuscular (IM) haloperidol (5 mg) and lorazepam (1 mg) were administered, and she calmed down over the next hour. However, a bilateral coarse tremor developed in her hands, her arms became increasingly stiff/rigid, her eyes appeared to roll upward, and she developed torticollis, which terrified her.
However, alcohol tremors have a higher frequency, mainly involving the hands. Cocaine abuse has numerous adverse side effects on the body, such as involuntary tremors. One common symptom reported or seen in drug addicts is tremors, also called Drug-Induced Movement Disorders (DIMD). If the benefit of the medicine is greater than the problems caused by the tremor, your provider may have you try different dosages of the medicine.
Acute dystonic reactions
It is symmetrical and occurs acutely following drug ingestion or dose escalation. Exceptions include tremor drug induced tremors secondary to valproate, which can appear at therapeutic or during stable treatment, or, rarely, tardive tremor. Tremor can occur secondary to many drugs, including SSRIs, lithium, tricyclic antidepressants, antiepileptics (particularly valproate), bronchodilators, amiodarone and immunosuppressives. Another underlying aetiology, such as Parkinson’s disease, essential tremor or hyperthyroidism, needs to be excluded. Bradykinesia, or slowness of movement, affects around 30-40% of patients with medication-induced movement disorders.
Acute disorders
This symptom is particularly concerning for older adults, who may be at a higher risk of injury from falls. Parkinsonism-hyperpyrexia disorder, also known as akinetic crisis, is a rare but potentially fatal complication of Parkinson’s disease. It can also be precipitated by an infection or other metabolic disturbance. It is also important to exclude alternative causes, including an underlying infection, metabolic abnormalities, or stroke. Tetrabenazine is an earlier VMAT-2 inhibitor; however, it is used as an agent of last resort due to its risk of significant side effects (eg, depression and suicidal ideation). In cases in which withdrawal of an antipsychotic does not reduce TD and when a VMAT-2 inhibitor or other agents are not used, some evidence indicates that switching to clozapine monotherapy can treat or reduce antipsychotic-induced TD.
Other than tachycardia, her vital signs were stable, including a normal oxygen saturation and temperature. In addition to the elevated creatine kinase, laboratory investigations usually find leucocytosis, abnormal electrolytes, renal impairment, abnormal liver function tests, and altered coagulation studies. Contact your provider if you are taking a medicine and a tremor develops that interferes with your activity or is accompanied by other symptoms. In rare cases, a medicine such as propranolol may be added to help control the tremor. You may not need treatment or changes in the medicine if the tremor is mild and does not interfere with your daily activity.
- Because drug-induced parkinsonism is caused by a medication, treatment usually involves identifying and then slowly discontinuing the drug.
- The tremors may not happen all of the time, but they’re likely to occur within the first hour of taking medication.
- Physiological tremor has many components that can be influenced by medications with some influencing the central component (amitriptyline) and others altering the peripheral component (β-adrenergic agonists, cyclosporine, etc.).
- Common illegal drugs that cause Drug-Induced Movement Disorders (DIMD) are cocaine, opioids, amphetamine, and heroin.
- Bromocriptine should therefore be continued for several weeks to ensure the syndrome has completely subsided.
Both therapeutic and illicit drugs can cause neurological adverse effects, including movement disorders. The most common causes of drug-induced movement disorders are dopamine receptor blocking drugs, including antipsychotics and antiemetics (Table 1). Drug-induced movement disorders can range from tremors to life-threatening syndromes. They can be classified chronologically based on the time of onset after drug ingestion, as acute, subacute or tardive.
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For example, the drug levodopa is commonly used to treat Parkinson’s disease, but may not improve symptoms of parkinsonism or pseudoparkinsonism. Your doctor will work with you to determine a treatment plan and then make changes as needed. If the medication cannot be stopped for other health reasons, your doctor may discuss other treatment options with you.
In contrast to idiopathic Parkinson’s disease, drug-induced parkinsonism usually presents as a symmetrical akinetic rigid syndrome which develops over days to weeks to months following ingestion of the offending drug. Additionally, there is a poor response to typical antiparkinsonian drugs, including levodopa, dopamine agonists and anticholinergic drugs. Cessation of the offending drug usually results in complete resolution of the disorder.
Immunosuppressants, which are used to prevent the rejection of transplanted organs, can also lead to drug-induced tremors. Drugs used to treat a variety of psychiatric disorders such as antipsychotics, lithium, and certain antidepressants are also potential causes of drug-induced tremors. Caffeine is a stimulant that can also cause you to have tremors or can worsen existing tremors. Some instances of these can manifest in people addicted to drugs or those who are experiencing withdrawal symptoms when they stop using drugs.
Facial grimacing, or involuntary facial movements, is a common feature of tardive dyskinesia and affects around 20-30% of patients with medication-induced movement disorders. These movements may include repetitive blinking, lip-smacking, or jaw clenching. Facial grimacing can be socially embarrassing and may lead to difficulties with eating or speaking.