Iontophoresis in Physical Therapy

Using Electrical Stimulation to Deliver Medication

If you have an injury that causes pain and limited mobility, you may benefit from working with a physical therapist (PT) to help decrease your pain and improve your function. Your PT may use various treatments to augment your rehab program. One such treatment is iontophoresis.

Iontophoresis is a therapeutic modality often used by physical therapists to treat a variety of conditions. It is a type of electrical stimulation that is used to administer medication into your body through your skin.

How Iontophoresis Work

To understand the basic principles of iontophoresis, you should remember some basic lessons from physics and chemistry class. In general, ionic charges that are alike will repel one another, while ions that are oppositely charged will be attracted to one another.

So if you have a medicine in a solution that is negatively charged and you apply a negative electrical charge to it, the medicine in solution will be pushed away, or repelled, from the negative electricity. When using iontophoresis, your physical therapist is using electricity to push medicine into your injured tissues.

The medication used in iontophoresis is ionically charged. So if your physical therapist decides to introduce medication into your injured tissues via iontophoresis and that medication is negatively charged, he or she will use a negative current to drive that medication into your body.

Common Uses

There are many different uses for iontophoresis. These include, but are not limited to:

  • Decrease inflammation
  • Decrease pain
  • Decrease muscle spasm
  • Decrease swelling and edema
  • Reduce calcium deposits in the body
  • Manage scar tissue

Your PT will work with you to decide on the treatment goals and the rationale for using iontophoresis.

Procedure

Before applying iontophoresis, your PT must first decide on which type of medication to use. The medication used in iontophoresis depends on the goals of the treatment. Different medications have different effects on the body, and your PT will decide on the best medication for your specific condition.

Iontophoresis can be used in physical therapy for the local delivery of anesthetics (such as lidocaine), cortisteroids, anti-inflammatory drugs. and analgesics to inflamed joints, muscles, and subcutaneous tissues.

Many states require that your PT obtain a prescription from your doctor before administering the medication into your body via iontophoresis. Don't be surprised if your therapist contacts your physician or asks you to contact your physician prior to administering iontophoresis medication.

A direct current electrical stimulation unit is used to apply iontophoresis. The unit has two electrodes; one electrode is for the negative current, and one is for the positive current. Your PT will apply medication to either the positive electrode or the negative one, depending on the type of medication that is being used for iontophoresis.

The electrodes are then applied to your body. The electrode with the medication is applied to the area of your body that is being treated. The electrode without the medication is applied to your body nearby. The electrical stimulation unit is then turned on, and the electricity pushes the medication into your injured body part while you relax.

What to Expect

When your physical therapist applies iontophoresis to your body, he or she uses an electrical stimulation device. When the electrical current is turned on, you will likely feel a slight tingling sensation. Sometimes the stimulation feels like a tiny bee sting. If you are uncomfortable during the iontophoresis treatment, notify your physical therapist and adjustments can be made.

A typical iontophoresis treatment takes 10 to 20 minutes, depending on the amount of medication that your PT is administering to you. When your iontophoresis treatment is completed, your PT will remove the electrodes and inspect your skin. Don't be surprised if your skin is red where the medication electrode was placed; this is common after iontophoresis.

Once you receive your iontophoresis treatment, your PT will give you specific instructions. Many times, withholding ice or heat treatments after iontophoresis is recommended since these treatments alter circulation to the injured area. This altered circulation might "wash away" the medication that was just introduced to your body. If you have any questions about what to do after iontophoresis, be sure to ask your physical therapist.

Side Effects

Iontophoresis is a safe procedure, and side effects are minimal. While receiving the stimulation, you may feel a slight pin prick tingling sensation. Redness may also occur underneath the electrodes used for it. Some patients notice some dryness or rough skin in the area where the iontophoresis was administered. This can be mitigated by using skin lotion over the area several hours after receiving the treatment.

In the literature review of 25 iontophoresis studies, including 13 randomized trials, rates of adverse skin reactions varied widely but were mostly mild and did not require treatment.

Keep in mind that iontophoresis is a passive treatment, and the most successful physical therapy programs require you to be actively involved in your care. Active exercises are often the most important component of your rehabilitation, so be sure that your PT gives you a strategy to manage your condition when you are not in the physical therapy clinic.

Contraindications

While generally considered safe, the procedure is not without its limitations and safety issues. When used for systemic drug delivery, iontophoresis machines are classified by the U.S. Food and Drug Administration (FDA) as a class 3 device alongside total artificial disc replacements and implanted neurostimulators.

Due to the lack of research into its affect on fetal health, iontophoresis is contraindicated in pregnancy. It is also contraindicated if you have a pacemaker, metal implant, cardiac arrhythmia, a skin rash, or skin disease.

Evidence

If your physical therapist considers using iontophoresis for your treatment, you should know if it is likely to be of benefit for your condition. Studies investigating iontophoresis have been performed, some of which are promising than eithe.

A 2015 study published in the journal Physiotherapy examined the role of lidocaine iontophoresis in the treatment of spasticity in children with cerebral palsy. Thirty children were randomized to one of two groups: those who received PT and iontophoresis, and those who only received PT. The group that received iontophoresis showed greater improvements in certain walking variables compared to the PT-only group.

Another study examined the effect of iontophoresis for shoulder impingement syndrome. Eighty-eight subjects with shoulder impingement were randomized into one of three groups: one a fake ultrasound and fake iontophoresis; another a fake ultrasound and real iontophoresis; and a third with a real ultrasound and fake iontophoresis. The group that received with real iontophoresis fared least well of all, although no negative reactions occurred.

In terms of systemic drug delivery, a 2013 study published in the British Journal of Clinical Pharmacology concluded that iontopheresis is "theoretically promising" and, depending on the aims of treatment, may offer advantages over a transdermal patch.

So, iontophoresis may be helpful for some conditions and not in others. But the most important study participant is you. If your PT suggests iontophoresis for your condition, it may be worth a try, but it should not be considered a panacea by any means.

A Word From Verywell

Iontophoresis, a form of electrical stimulation, can be an important part of your physical therapy treatment. It is used introduce medication into your body to achieve specific therapeutic goals. Iontophoresis may be one treatment that can help you return to normal activity quickly and safely after injury.

Medications Used in Iontophoresis
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Article Sources
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  • García, I., Lobo, C., López, E., Serván, J. L., & Tenías, J. M. (2016). Comparative effectiveness of ultrasonophoresis and iontophoresis in impingement syndrome: a double-blind, randomized, placebo controlled trial. Clinical rehabilitation30(4), 347-358.

  • Hegazy, F., Salem, Y., & Aboelnasr, E. (2015). Lidocaine iontophoresis combined with physical therapy interventions for children with spastic hemiplegic cerebral palsy. Physiotherapy101, e554-e555.

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