How Iontophoresis Works
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 the solution will be repelled (pushed away) 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 introduces negatively charged medication into your injured tissues via iontophoresis, they 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.
Many states require that your PT obtain a prescription from your healthcare provider before administering the medication into your body via iontophoresis. Don’t be surprised if your therapist contacts your healthcare provider or asks you to contact your healthcare provider 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, they use 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 temperature changes 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.
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.
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.
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 with placebo ultrasonophoresis and placebo iontophoresis; another with placebo ultrasonophoresis and real iontophoresis; and a third with a real ultrasonophoresis and placebo iontophoresis. The group that received only iontophoresis (without ultrasonophoresis) showed no significant improvements when added to the standard treatment.
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 to 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.
