Electrical stimulation applied to a woman's rotator cuff.
Your physical therapist may apply NMES to your muscles to help them function better.. E+/Getty Images

Definition: Iontophoresis is a type of electrical stimulation treatment used to deliver medication across your skin to deeper tissues.

Physical therapists occasionally use iontophoresis to deliver different types of medication to injured body parts.

How Does Iontophoresis Work?

Iontophoresis works by using electricity to push medication through your skin and into your injured tissues. This works by using basic ideas of electrical polarity.

The medication used in iontophoresis is in a solution with a specific type of polarity (either positive or negative). Remember, opposite polarity attracts, and negative polarity repels.

For example, dexamethasone, a common anti-inflammatory medication, may be placed in a solution with negative polarity. When electricity from the negative electrode of an electrical stimulation device is applied to the dexamethasone, the medication will be repelled by the electrical charge. This helps to drive the medication into your skin and underlying tissues.

Different Medications Used with Iontophoresis

Different medication can be used to accomplish different things with iontophoresis. These may include:

  • Calcium Chloride: Used to decrease muscle spasm.
  • Tap Water: Tap water is used to help decreased hyperhidrosis, a condition that causes sweaty palms and feet.
  • Magnesium Sulfate: Medication used to treat muscle pain and spasm.
  • Iodine: Used to treat sclerotic conditions such as frozen shoulder, and it may help to increase circulation to tissues.
  • Hyaluronidase: Commonly used to treat soft tissue swelling and edema.

What Does Iontophoresis Feel Like?

When your physical therapist decides to administer medication via iontophoresis, he or she should explain to you the risks and benefits associated with the procedure. He or she will then place two electrodes on your skin. One electrode will simply have saline on it, and the other electrode will be the treatment electrode with the medication. The electrodes will be connected to an iontophoresis unit via a wire.

Your PT will then turn on the iontophoresis unit and slowly increase the intensity of the electricity that is passing through the electrodes. This electricity helps to drive the medication in through your skin and to your tissues. Once the electricity is turned up, you may feel a slight tingling or stinging sensation under the electrodes.

Be sure to tell your physical therapist if you feel any discomfort or pain during the procedure. He or he can make adjustments to the electricity to make it more comfortable for you.

Risks of Iontophoresis

Iontophoresis is a form of electrical stimulation, and not every person is a suitable candidate to receive such a treatment. If you have a permanent pacemaker placed in your heart, you should not use electrical stimulation. It may have an adverse reaction with your pacemaker and may place you at risk for death should a cardiac event occur while using the electrical stimulation.

Risks of iontophoresis include:

  • Adverse reaction to the medication
  • Adverse reaction to the electrical current.
  • Burn lesion to the skin

When dealing with various injuries, your PT may use iontophoresis to help augment your active rehab program. By understanding iontophoresis and how it is used, you can make an informed decision about your care.

Pronunciation: (ī′än·tə·fə′rē·səs)

Edited by Brett Sears, PT, Expert in Physical Therapy

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