In several instances, the electrophysiological differences were deemed insignificant 7, 8, 10, 11, while in other cases, such measurements were not recorded 10, 12, 13. Further, such findings could provide valuable insights into the etiology of the condition. According to current evidence, gabapentin is the drug with the most robust data.
Over the next 30 minutes, her tremor, rigidity, eye movement deviation, and torticollis gradually resolved. All laboratory testing, including a comprehensive metabolic panel, liver function tests, thyroid function tests, and serum and urine toxicology screens, were within normal limits. A physical and neurologic examination revealed no additional abnormalities. Stop the offending drug, and give an intravenous or intramuscular anticholinergic drug (such as benzatropine or trihexyphenidyl (benzhexol) hydrochloride).
Anticholinergics, beta blockers, benzodiazepines, amantadine, mirtazapine and clonidine have also been used with varying efficacy and with minimal evidence.
Additionally, Drug-Induced Movement Disorders will interfere with your quality of life. 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. Hopefully this further knowledge will lead to better therapeutics for pathological tremors and allow us to develop less tremorogenic drugs. One double-blind placebo-controlled crossover study by Rodrigues et al. 10 investigated the effect of gabapentin compared to placebo over a two-week period in six patients.
Medication-induced tremors: background and pathophysiology
Obtaining a complete psychiatric history from someone who has developed abnormal muscle movements is crucial to refining the differential diagnosis and mapping out a treatment plan. Details of the location and nature of the abnormal movements, their onset and progression, and their aggravating and relieving factors are essential. Another important aspect of the history is a review of the neurologic and neurodevelopmental history. A history of a seizure disorder might provide insight into the causes of stereotypic movements. A history of a recent stroke might contribute to athetosis, while a traumatic brain injury or Parkinson’s disease (PD) can cause akathisia or tremors. Similarly, patients with autism spectrum disorder often have stereotypic movements, while motor tics are often comorbid with attention-deficit/hyperactivity disorder (ADHD), Tourette syndrome, or obsessive-compulsive disorder (OCD).
Table 1. Drug-induced movements disorders.
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.). Other mechanisms include blockade of dopaminergic neurotransmission in the nigrostriatal pathway by DBA or dopamine-depleting agents. Cerebellar damage due to longstanding abuse (ethanol) or toxic states can also cause intention tremors that can be quite bothersome. MITs are common in clinical practice, occur with many medications, and are often very treatable by reducing the dose of the drug, switching to a controlled-release preparation, or drug induced tremors switching to another agent. In some cases, it is not possible to reduce the dose of the offending agent and additional medication (e.g., propranolol) may be necessary to try and treat the tremor.
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Long-term use of certain medications, such as antipsychotics, antidepressants, and anti-nausea drugs, also increases the likelihood of developing MIMDs. DIMDs remain a significant burden among certain patient populations, such as those receiving treatment with dopamine receptorÒblocking agents (DRBAs; e.g., various psychotropic agents and antiemetics) (TABLE 2). DIMDs are often underrecognized, and knowledge of DIMDs will allow clinicians, pharmacists, and other health care professionals to better identify and manage patients with these conditions.
- However, no additional studies matching the inclusion criteria were found that investigate the use of botulinum toxin in primary orthostatic tremor.
- Postural tremor occurs classically when maintaining the arms in an outstretched position against gravity.
- She was diagnosed with an acute dystonic reaction due to administration of haloperidol, and an adverse reaction warning was entered into her electronic medical record.
- In the study conducted by Gironell and Marín-Lahoz, 92% of the participants showed symptomatic improvement with perampanel 13.
- Bradykinesia can make it difficult to initiate movements, and patients may feel as though their body is moving in slow motion.
TABLE 1.
Parasomnias are a group of sleep disorders characterised by abnormal behavioural, experiential, or physiological events occurring during sleep or sleep–wake transitions (Association AP, 2013). They are highly prevalent in the general population and the lifetime prevalence of the different parasomnia varied from about 4% and 67% of the general population (Akkaoui et al., 2020; Bjorvatn et al., 2010). They can occur during the non‐rapid eye movement (NREM) and rapid eye movement (REM) stages of sleep. Sleepwalking is a NREM parasomnia, which consists of complex behaviours that are initiated during slow‐wave sleep and result in ambulation.
Anticonvulsant drugs are among the most common causes of drug-induced tremors. Anticonvulsants are used for a variety of medical conditions, including epilepsy and bipolar disorder. Bronchodilators, which are commonly used in the treatment of conditions such as asthma, can also cause tremors. A tremor is an involuntary, rhythmic shaking of any part of the body that you cannot control. It occurs due to muscle contractions and can affect the hands, head, arms, legs, trunk, or vocal cords. Tremors can be symptoms of certain medical conditions like Parkinson’s disease.
Regarding bruxism, the hypotheses raised involve dysregulation of mesocortical pathway or a downregulation of nigrostriatal pathway, related to medications involving dopamine or serotonin. Parasomnias are rarely identified in drug product labels, likely due to the recent classification of their diagnoses. An analysis of pharmacovigilance data could be valuable to supplement existing literature data. Medication-induced movement disorders occur when certain medications interfere with the brain’s ability to regulate movement. These disorders can manifest as involuntary muscle contractions, tremors, or difficulty with coordination. The most common types of MIMDs include tardive dyskinesia, drug-induced parkinsonism, and akathisia.
Clinical Points
Again, it would be best to seek medical attention if you experience these symptoms. Cocaine abuse may also cause subtle parkinsonian symptoms like tremors at rest. Crack dancing is characterized by involuntary limb movements that last for several days at a time. If you are an addict, the spontaneous movements may not seem apparent to you. 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.
Intermittent apomorphine injections or a continuous infusion may be required in moderate–severe cases. The time of onset of the movement disorder may be acute, subacute, or chronic. A tremor that occurs when the muscles are relaxed or that affects the legs or coordination may be a sign of another condition, such as Parkinson disease. Depending on the duration of dyskinesia, the levodopa dose can usually be reduced to a lower dose which still maintains efficacy. It is worth noting that mild dyskinesias are often not bothersome to the individual and do not interfere with their function, therefore a change in levodopa dose may not be required.
Dystonia can affect any part of the body, including the neck, face, or limbs. These contractions can be painful and may interfere with daily activities. Dystonia is believed to result from an imbalance in neurotransmitters, particularly dopamine, which leads to abnormal muscle control.
Tardive dyskinesia, for example, is characterized by repetitive, jerky movements, often in the face or limbs. Drug-induced parkinsonism mimics Parkinson’s disease symptoms, such as stiffness and slow movements. Patients with certain medical conditions are more likely to develop medication-induced movement disorders. For instance, individuals with a history of neurological conditions, such as Parkinson’s disease, may be more susceptible to drug-induced parkinsonism. Additionally, patients with mental health disorders, such as schizophrenia or bipolar disorder, who are prescribed antipsychotic medications, are at higher risk of developing tardive dyskinesia and other movement-related side effects.
Drug-induced tremor, clinical features, diagnostic approach and management
Parasomnias and sleep‐related movement disorders (SRMD) are major causes of sleep disorders and may be drug induced. The objective of this study was to conduct a systematic review of the literature to examine the association between drug use and the occurrence of parasomnias and SRMD. Following Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines for reporting systematic reviews, we searched PubMed databases between January 2020 and June 2023. The searches retrieved 937 records, of which 174 publications were selected for full‐text screening and 73 drugs were identified. The most common drug‐induced parasomnias were nightmares and rapid eye movement (REM) sleep behaviour disorders and sleepwalking.
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).
