Author: John Carter
Drug-induced movement disorders PMC
Knowledge of the different kinds of tremor in psychiatry, and the drugs that may be responsible. If you begin to experience any side effects while taking an antipsychotic, talk to your doctor as soon as possible. In some cases, they can be permanent, but treatment often leads to improvement.
In some cases, extrapyramidal symptoms may not affect you too much. They can negatively affect quality of life and contribute to frustration and distress. If you begin to experience hallucinations, delusions, or other distressing symptoms, get help right away.
Another underlying aetiology, such as Parkinson’s disease, essential tremor or hyperthyroidism, needs to be excluded. Tardive drug-induced movement disorders occur either during exposure or within weeks of stopping a drug and are present for at least one month.1,11-14 The minimum duration of exposure to the drug is three months, or one month in adults aged over 60 years. The most commonly implicated drugs include antipsychotics, antiemetics (metoclopramide and prochlorperazine) and some calcium channel antagonists with dopamine receptor blocking properties (cinnarizine and flunarizine).
Drug-Induced Tremor
In rare instances where clinically appropriate, deep brain stimulation surgery may be necessary to ameliorate the tremor. Subacute drug-induced movement disorders occur within days to weeks of drug ingestion. Parkinsonism-hyperpyrexia disorder, also known as akinetic crisis, is a rare but potentially fatal complication of Parkinson’s disease.
- Differentiation can often be made according to the time of onset, relation with starting or increasing the dosage of the medication and the course.
- Dystonia can cause painful muscle stiffness and other discomfort.
- Finally, isometric tremor is a kinetic tremor that occurs with active muscle contraction against a fixed object.
- Between 20 and 40 percent of people taking antipsychotics develop Parkinsonian symptoms.
- Stimulant medications and drugs containing theophylline should be used with caution.
Patients are often on combinations of drugs that may cause more than one movement disorder, thereby making it challenging to identify the culprit drug. The diagnosis requires knowledge of the typical movement disorders and the syndromes that can occur with different drug classes, and their typical time course. This is important because the most imperative therapeutic intervention for most drug-induced movement disorders is stopping the offending drug, with or without supportive or other pharmacological treatment. MIT has provided some insight into the mechanisms of tremors we see in clinical practice. The exact mechanism of MIT is unknown for most medications that cause tremor, but it is assumed that in most cases physiological tremor is influenced by these medications. Some medications (epinephrine) that cause EPT likely lead to tremor by peripheral mechanisms in the muscle (β-adrenergic agonists), but others may influence the central component (amitriptyline).
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. Or, you may be prescribed another medicine to treat your condition. In rare cases, a drug such as propranolol may be added to help control the tremor. If you’re prescribed a lower dose of antipsychotic, tell your doctor or therapist if you begin having symptoms of psychosis or other symptoms your medication is meant to treat. It’s important to watch out for these symptoms if you or a loved one is taking an antipsychotic. Drug side effects sometimes resemble the symptoms of the condition a drug is being used to treat, but a doctor can help diagnose symptoms.
Drug-induced tremor
Two major categories of tremor are resting tremor and action tremor. Resting tremor (as typically occurs in DIP or PD) is commonly 4–6 Hz in frequency and occurs when the affected body part is fully supported without ongoing voluntary muscle contraction. Action tremor, in contrast, occurs with voluntary movement and can be divided into postural tremor and kinetic tremor. Postural tremor occurs classically when maintaining the arms in an outstretched position against gravity.
Resting tremor typically worsens with distraction and goes away during sleep. Physiological tremor is an action tremor that is mediated by both central and peripheral mechanisms.17,18 It consists of low-amplitude, high-frequency (8–12 Hz) oscillations depending on the stiffness, mass, and other properties of the tremoring body part. EPT can be very similar in appearance and characteristics to ET when EPT becomes clinically symptomatic. Movement disorders are a common, and at times life-threatening, adverse effect of many drugs, most commonly dopamine receptor blocking drugs.
If this is not possible then anticholinergics or amantadine are often used to combat symptoms. This is similar to findings in PD where deep brain stimulation of the VIM nucleus of the thalamus, subthalamic nucleus, or GPi can improve resting tremor. In order to understand the phenomenology of MIT, discussed below, we will briefly review the basics of tremors.17,18 Tremors are typically characterized by rhythmic oscillations of a body part about a joint and are best classified by the situation in which it occurs.
Tremor phenomenology
Bromocriptine should therefore be continued for several weeks to ensure the syndrome has completely subsided. Consideration about restarting an antipsychotic requires a specialist psychiatric opinion. Caffeine can cause tremor and make tremor caused by other medicines worse. If you have a tremor, avoid caffeinated drinks such as coffee, tea, and soda. You may not need treatment or changes in the medicine if the tremor is mild and does not interfere with your daily activity.
Akathisia has been reported with dopamine receptor blockers, selective serotonin reuptake inhibitors (SSRIs), antiepileptic drugs, and cocaine. It can occur either after starting a dopamine receptor blocker, dose escalation, or when switching to an alternative drug. As mentioned previously, resting tremor in DIP due to DBA can be asymmetric in many patients.2–5 Treatment of MIT due to DBA is aimed at reducing the dose of the offending drug or attempting to eliminate it completely.
Benzodiazepines can be used to reduce rhabdomyolysis and improve rigidity. Finally, it will be important to further define the most vital anatomical structures for the generation of tremor in the CNS and further understand the physiology of these interconnected players. It will also be important to develop further knowledge of neurotransmitters and their receptors that may influence tremor or actually suppress it.
Drug-induced tremors are caused by your brain’s response to the chemicals in certain medications. Drug-induced tremors can also occur as the result of withdrawal from drugs or alcohol. Tremors can occur in the setting of withdrawal states, especially with benzodiazepines, ethanol, and opiates. One well-performed study found that patients undergoing ethanol withdrawal had tremors in the range of 8–12 Hz.74 When patients abruptly stop β-adrenergic antagonists such as propranolol, an increase in action and postural tremor can be observed as well. Even 1 month after discontinuing propranolol, increased tremor power was observed in subjects without underlying tremor disorders who were being treated for cardiac conditions.75 Most withdrawal-related tremors appear typical of EPT as with most MIT.
These drugs have less affinity for dopamine receptors and bind loosely and block some serotonin receptors. Tardive movement disorders include dyskinesias (typically orobuccolingual), stereotypies, akathisia, dystonia (focal, segmental or generalised), myoclonus, tremor and tics. Withdrawal-emergent dyskinesia can occur on abrupt cessation of long-term antipsychotic treatment, particularly in children.
No good evidence exists regarding the management of tardive drug-induced movement disorders.15 Treatment usually consists of withdrawing the offending drug, and a trial of a combination of drugs. Resuming the offending drug or changing to an atypical antipsychotic is sometimes required.16 In patients with a chronic psychotic disorder clozapine is preferred. Most recently, vesicular monoamine transporter 2 inhibitors deutetrabenazine and valbenazine have been proposed as treatment options.17,18 Other oral drugs have been tried, including tetrabenazine, amantadine and propranolol. Extrapyramidal symptoms, also called drug induced movement disorders, describe the side effects caused by certain antipsychotic and other drugs.