Prescription Form and Prescribing Information

To ensure efficient fulfillment of submitted prescriptions, please follow the following instructions completely.

1. Review indications and contraindications

Indications for Use: To aid in the transient relief of hand tremors in the treated hand following stimulation in adults with essential tremor (ET).

Contraindications: Cala Trio Therapy System should NOT be used

  • by patients with an implanted electrical medical device, such as a pacemaker, defibrillator, or deep brain stimulator.
  • by patients that have suspected or diagnosed epilepsy or other seizure disorder.
  • by patients who are pregnant.
  • on swollen, infected, inflamed areas, or skin eruptions, open wounds, or cancerous lesions.

2. Choose which hand to treat

Cala Trio is designed to stimulate nerves in the left OR right wrist. Device is not interchangeable; note how right-hand therapy is administered.

3. Measure Wrist Size; select Small, Medium, Large

Fit and placement of the Cala Trio are essential to therapeutic efficacy. Read tips to measure wrist when the patient is self-measuring or if the measurement tool is not available, read tips here.

Illustration of wrist measurement tool

4. Select “tremor task”

The “tremor task” is a postural hold that is repeated to characterize the patient’s tremor. Advise the patient that this specific “Tremor Task” will be performed when the device prompts them for a tremor task. Assess both tasks and choose the more severe postural hold.

Illustration of tremor task test

5. Download the Cala Trio Prescription Form interactive PDF to your computer

Cala Trio Prescription Form


  • Once you download the Cala Trio Prescription Form to your computer, you can save your Prescriber information at the top of the Cala Trio Prescription Form to save time when writing multiple RXs. The Cala Trio Prescription Form PDF has a digital signature option
  • Fax the completed and signed Cala Trio Prescription Form to Sfax (833) 230-9251 or Fax (650) 729-1156

Safety Information

This lists Contraindications and general Warnings, and Cautions related to the use of Cala Trio therapy. Those Warnings and Cautions pertaining to specific functions or procedures are included throughout the Health Care Professional Guide.


The device should NOT be used:

  • by patients with an implanted electrical medical device, such as a pacemaker, defibrillator, or deep brain stimulator.
  • by patients that have suspected or diagnosed epilepsy or other seizure disorder.
  • by patients who are pregnant.
  • on swollen, infected, inflamed areas, or skin eruptions, open wounds, or cancerous lesions.


  • Do not use this device on patients who have a cardiac pacemaker, implanted defibrillator, or other implanted electronic device, or implanted metal in the wrist, because this may cause electric shock, burns, electrical interference, or death.
  • Do not use the device while sleeping, driving, bathing, operating machinery, or during any activity in which possible involuntary muscle contractions due to stimulation may cause undue risk of injury.
  • Do not use the device near the head, directly on the eyes, covering the mouth, upper back, crossing over the heart, or on diseased skin.
  • Do not use the device on the neck because this could cause severe muscle spasm resulting in closure of the airway, difficulty in breathing, or adverse effects on heart rhythm.
  • Do not use the device on the chest because introduction of electric current into the chest may cause rhythm disturbances to the patient’s heart, which could cause death.
  • Do not apply the device near the thorax, as this may increase the risk of arrhythmia.
  • Do not apply stimulation over open wounds or rashes, or over swollen, red, infected, or inflamed areas or skin eruptions (e.g., phlebitis, thrombophlebitis, varicose veins, etc.).
  • Do not apply stimulation over, or in proximity to, cancerous lesions.
  • To prevent electrical shock, do not immerse the device in water or wear while performing activities where the device is under water, such as swimming or bathing.
  • Do not use the device simultaneously with:
    • high frequency surgical equipment, as this may result in electrical burns and/or possible damage to the device.
    • electronic monitoring equipment (e.g., cardiac monitors, ECG alarms), which may not operate properly when the electrical stimulation device is in use.
  • To prevent an explosion hazard and possible patient injury, instruct the patient to stop stimulation from the device when at a refueling place (e.g., gas station). Do not use the device near flammable fuel, fumes, or chemicals.
  • Implanting-physician approval should be obtained by the prescribing physician before using on patients with implanted devices at the site of stimulation. Use of the device with some implants is contraindicated – see Contraindications for details.
  • The long-term effects of chronic electrical stimulation are unknown.


  • The device has only been evaluated in subjects diagnosed with Essential Tremor and the effectiveness of the device has not been evaluated for tremor associated with other conditions.
  • Use the device only as directed by the Healthcare Professional Guide and the Patient Guide.
  • The safety of electrical stimulation during pregnancy has not been established.
  • Store the device to prevent exposure to dust, direct sunlight, and pests. It is recommended to store the device in the original packaging when not in use or being charged.
  • To prevent damage to the device and/or performance issues:
    • Keep the device dry.
    • Avoid the formation of condensation on the device. When moving the device between hot and cold temperatures, place it in an airtight plastic bag and let it slowly adjust to the temperature change before use.
    • Do not use the device in places with high humidity, such as the bathroom.
    • Do not store or transport the device or its accessories in temperatures that exceed the recommended storage temperature range: -20°C to 45°C (-4°F to 113°F). Do not operate the device in temperatures that exceed the recommended operation temperature range of 5°C to 35°C (41°F to 95°F). Temperature extremes can damage the device and accessories.
    • Do not tamper with, modify, or attempt to perform maintenance or servicing on the device.
    • Do not use the device in close proximity (e.g., within 1 meter) to shortwave or microwave therapy equipment.
  • To prevent damage, performance issues, increased emissions, or decreased immunity of the device only use the accessories recommended by Cala Health with the device. The device claims compliance for electromagnetic compatibility levels in conjunction with the charger (see Section 10).
  • Advise patients to use the device with caution:
    • If the patient has a tendency to bleed following an injury.
    • Over areas of the skin that lack normal sensation.
  • Keep out of the reach of children and pets.
  • The device is single-patient use by the individual for whom it has been prescribed. It should not be worn by anyone else or on any other part of the body.
  • To avoid interfering with diagnostic assessments, advise the patient to not wear the device during x-ray examinations.
  • Should any technical problem occur that is not covered in the Healthcare Professional Guide or the Patient Guide, please contact Cala Health.

Adverse Reactions

The following are possible minor risks or adverse reactions that may occur with the use of the device:

  • Discomfort with stimulation.
  • Allergic reaction to electrodes or other materials.
  • Skin irritation, including redness and/or itching.

In the unlikely event that any of the following more significant issues occur, advise the patient to stop using the device immediately and to consult a physician:

  • Signs of significant and persistent skin irritation, sores, electrical burns or lesions at the site of stimulation.
  • Significant and persistent increase in muscle tightness or stiffness.
  • A feeling of chest pressure during stimulation.
  • Swelling of the arm, wrist, or hand.

Skin Care Guidelines

The device works by electrically stimulating nerves through the skin. It is important for the patient to inspect their skin where it contacts the electrodes to minimize risk of skin irritation. To promote good electrode connection and healthy skin, instruct the patient to follow these skin care guidelines:

  • Wet your wrist before donning Cala Trio.
  • If there is any excess oil or lotion on your wrist, wash with soap and water and rinse well before wearing Cala Trio.
  • Always check the skin for irritation, redness, or rash when putting on and taking off Cala Trio.