What are the other Names for this Condition? (Also known as/Synonyms)

• Drug-Induced Parkinsonism
• Medication-Induced Tremor

What is Drug-Induced Tremor? (Definition/Background Information)

• Drug-Induced Tremor is the involuntary shaking of one’s arms, hands, head, eyelids, or sometimes, the lower body. The condition is a response of the nervous system to the use/abuse of certain medications
• Any individual may be affected by Drug-Induced Tremor. Alcohol, nicotine, and caffeine can all cause or exacerbate the tremors. The condition can be caused by a wide array of drugs and substances
• Severe Drug-Induced Tremor can make fine-motor tasks extremely difficult and lower one’s quality of daily life. A thorough physical examination and an analysis of the patient’s medical history can often provide enough information to diagnose the condition
• Reducing drug dosage or stopping usage of the drug causing the tremor can usually help improve the symptoms, or completely stop the tremors. Usually the shaking stops, if the individual discontinues the causative medication
• In a majority of individuals, the prognosis of Drug-Induced Tremor is excellent following the institution of appropriate treatment measures

Who gets Drug-Induced Tremor? (Age and Sex Distribution)

• Drug-Induced Tremor can occur in any individual taking the causative medications (drugs that cause the tremors)
• This condition appears to be observed equally among males and females
• Worldwide, all racial and ethnic groups may be affected

What are the Risk Factors for Drug-Induced Tremor? (Predisposing Factors)

Some of the predisposing factors for Drug-Induced Tremor include:

• Drinking alcohol
• Nicotine intake via smoking cigarettes, chewing tobacco, etc.
• Caffeine consumption

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others. 

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Drug-Induced Tremor? (Etiology)

Drug-Induced Tremor may be caused by a variety of medications and substances including:

• Asthma medications (theophylline or albuterol)
• Seizure medications (depakote or depakene)
• Cancer medications (thalidomide or cytarabine)
• Immune-suppressing medications (cyclosporine or tacrolimus)
• Mood stabilizers (lithium carbonate)
• Stimulants (caffeine or amphetamines)
• Selective serotonin reuptake inhibitors (SSRIs)
• Tricyclic antidepressants 
• Heart medications (amiodarone and procainamide)
• Certain antibiotics (azithromycin) and antiviral agents (acyclovir or vidarabine)
• Alcohol
• Nicotine
• Certain high blood pressure medications
• Epinephrine or norepinephrine
• Weight loss medication (tiratricol)
• Excess intake of thyroid medication (levothyroxine) or movement disorder medication (tetrabenzine) 

Sometimes, the appearance of signs and symptoms due to the medication may not be observed immediately following its usage.

What are the Signs and Symptoms of Drug-Induced Tremor?

The signs and symptoms of Drug-Induced Tremor may vary from one individual to another, depending on the medication and age of the affected individual. Neurologically, Drug-Induced Tremor patients often appear healthy.

The signs and symptoms may include:

• Tremors: Uncontrollable shaking of the hands, arms, head, eyelids, or sometimes lower body
• Drug-Induced Tremors can manifest in a variety of tremor patterns that include:
  • Episodic: Shorts bursts of shaking occurring at specific intervals after taking the medication
  • Intermittent that is sometimes triggered by activity
  • Sporadic, meaning it appears to take place at random
• Drug-Induced Tremors may:
  • Disappear during sleep
  • Begin at rest or with movement
  • Get worse during voluntary movement or with emotional stress
• Other symptoms include:
  • Trembling of the voice
  • Involuntary head nodding

The severity of the signs and symptoms may be related to usage of the drug.

How is Drug-Induced Tremor Diagnosed?

A diagnosis of Drug-Induced Tremor is made by the following observations and tests:

• A physical examination and medical history
  • Tremors can be observed during a physical examination
  • Examination of the individual’s medical history to see current medication use
• Drug-Induced Tremor is often diagnosed by the observation that tremors disappear after stoppage of the offending medication 
• The quality and nature of tremor must be examined to rule out other causes for tremors such as:
  • Alcohol withdrawal
  • Cigarette smoking
  • Hyperthyroidism
  • Parkinson’s disease
  • Pheochromocytoma
  • Excessive caffeine consumption
  • Wilson disease
  • A tremor that affects coordination may be an indication of Parkinson’s disease
• Despite the symptoms, CT scans, MRIs, and X-rays usually appear normal
• Other conditions that present similar signs and symptoms should be ruled out

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Drug-Induced Tremor?

• Severe Drug-Induced Tremor can affect daily activities requiring fine motor movements, resulting in complications during activities such as:
  • Eating
  • Drinking
  • Writing
  • Typing
• Emotional stress that can affect the quality of life

How is Drug-Induced Tremor Treated?

Treatments for Drug-Induced Tremor depend on the severity of shaking and the type of medication causing the condition.

• Discontinuing the drug responsible for the tremors may result in a cure, or in improvement of the condition
• Dosages of the medication causing the shaking may be adjusted/reduced, if the symptoms are severe
• It is important to consult a healthcare provider before stopping usage of any medication. The benefits of the earlier prescribed medication may far outweigh the tremors
• Rarely, a drug, such as propranolol, may be used to treat the symptoms of Drug-Induced Tremor

How can Drug-Induced Tremor be Prevented?

Current medical research has not established a method of preventing Drug-Induced Tremor. However, the following may be observed:

• Drugs that cause the condition may be discontinued or alternative medications used; else, dose-adjustment of current medication may be brought about
• Do inform the physician of any drug allergies
• Periodic monitoring or follow-up of the condition with the healthcare provider is recommended

It is important to consult with a healthcare provider about the side effects of over-the-counter medications that contain stimulants. 

What is the Prognosis of Drug-Induced Tremor? (Outcomes/Resolutions)

• The prognosis for individuals with Drug-Induced Tremor is usually a complete recovery after reducing the drug dose or ceasing usage of the drug causing the tremor
• If the tremor does not stop following cessation of medication use, contacting a healthcare professional for further follow up tests is essential

Additional and Relevant Useful Information for Drug-Induced Tremors:

Tremor comes for the Latin word tremere which means “to tremble”.