Iontophoresis

 

Iontophoresis is a physical process in which ions flow diffusively in a medium driven by an applied electric field. Iontophoresis is to be distinguished from the carriage of uncharged molecules by diffusive fluxes of other molecules, especially of solvent molecules, for example by electro-osmosis, that is to say by flux of uncharged solvent molecules carried as a cross-effect of iontophoresis. These phenomena, directly and indirectly, constitute active transport of matter due to an applied electric field. The transport is measured in units of chemical flux, commonly µmol/cm2h. The transport of a charged species of interest may also be measured in terms of a representative electric current, but that current might not be the whole of the current driven by the applied electric field.

Iontophoresis has experimental, therapeutic and diagnostic applications.

 

Therapeutic uses

Therapeutically, electromotive drug administration (EMDA) delivers a medicine or other chemical through the skin. In a manner of speaking, it is an injection without a needle, and may be described as non-invasive. It is different from dermal patches, which do not rely on an electric field. It drives a charged substance, usually a medication or bioactive agent, transdermally by repulsive electromotive force, through the skin. A small electric current is applied to an iontophoretic chamber placed on the skin, containing a charged active agent and its solvent vehicle. Another chamber or a skin electrode carries the return current. One or two chambers are filled with a solution containing an active ingredient and its solvent vehicle. The positively charged chamber, called the anode, will repel a positively charged chemical species, whereas the negatively charged chamber, called the cathode, will repel a negatively charged species into the skin.

Common diagnoses treated with iontophoresis include plantar fasciitis, bursitis, lateral and medial epicondylitis (commonly referred to as tennis elbow and golfers elbow respectively) and some types of palmar-plantar hyperhidrosis.

Iontophoresis is commonly used by physical therapists and occupational therapists for the application of anti-inflammatory medications.

In the treatment of hyperhidrosis, tap water is often the chosen solution for mild and medium forms. In very serious cases of hyperhidrosis, a solution containing glycopyrronium bromide or glycopyrrolate, a cholinergic inhibitor can be used.

Electromotive drug administration (EMDA) is also used in conjunction with Mitomycin C to reduce the probability of recurrence of bladder cancer after surgical removal of the tumor. In this application the current is delivered through between a catheter electrode and patch electrodes applied to the skin in the abdominal region.

Two iontophoretic patches have recently been approved for vaso-active therapeutic use by the FDA - Zecuity (2013) - containing the migraine drug sumatriptan - and Ionsys (2015), indicated for moderate-to-severe acute post-operative pain, delivering a therapeutic dose of the powerful opioid, fentanyl, on-demand. The entry of iontophoretic devices into the therapeutic mainstream will be followed with interest.

What Is Iontophoresis?

Highlights

Iontophoresis is a safe medical procedure that involves sending mild electrical currents through water and into the skin. It’s usually used to treat excessive sweating. However, it can also be used to treat sports injuries by delivering anti-inflammatory medications directly into the skin.
When treating excessive sweating, iontophoresis treatments must be done indefinitely to maintain desired results.
When treating sports injuries, iontophoresis treatments are only necessary until an injury begins to heal.

During iontophoresis, a medical device delivers mild electrical currents while your affected body part is submerged in water. The currents are often delivered to the hands, feet, or armpits to block your sweat glands temporarily. Some people feel a slight tingling sensation during the procedure, but the electrical current isn’t strong enough to shock you.

Iontophoresis is most commonly used to treat hyperhidrosis disorder, a condition that results in persistent and excessive sweating. This sweating may occur in certain situations, such as during warm weather or physical activity, or without any trigger at all. It can also be caused by other medical conditions, such as hyperthyroidism or menopause.

Aside from treating hyperhidrosis, iontophoresis may also be used to treat sports injuries by delivering anti-inflammatory medications directly into the skin.


Why Is Iontophoresis Performed?

Everyone sweats, but some people sweat more than others. People who frequently experience excessive or constant sweating for no apparent reason may have a condition called hyperhidrosis disorder.Iontophoresis is one type of treatment that can be used to relieve symptoms of this condition. People with hyperhidrosis may undergo several iontophoresis sessions per week, each lasting about 20 to 40 minutes.

Doctors aren’t exactly sure why iontophoresis helps people with hyperhidrosis. However, it’s believed that the procedure blocks sweat from coming out of the sweat glands, temporarily stopping sweating.

Though iontophoresis is most often used to treat severe sweating, it may also be used to treat a variety of sports injuries. Adding anti-inflammatory medicines to the water during iontophoresis can ease heel pain and other soft-tissue injuries. The electrical current helps the skin easily absorb the medications. Iontophoresis can be especially effective in reducing swelling around the joints and relieving pain. However, sprains or bursitis may respond well to this type of treatment.

How Do I Prepare for Iontophoresis?


Iontophoresis doesn’t require any special or advanced preparation. However, make sure to tell your doctor if you:
 

• Are pregnant

• Have epilepsy

• Have a heart condition

• Have a pacemaker or other metal implants, such as artificial joint replacements

You may not be able to undergo iontophoresis if you have any of the above medical conditions or devices. If this is the case, your doctor will recommend other options.

If you can undergo iontophoresis, it helps to apply a small amount of petroleum jelly to any cuts or scratches on your skin before beginning a session. This will protect open wounds from irritation during treatment. If you’re performing an iontophoresis treatment at home, it’s also beneficial to add a teaspoon of baking soda to the water beforehand. This will regulate the pH level of the water and help ensure treatment is effective.

What Happens During Iontophoresis?

When being used as a treatment for hyperhidrosis, iontophoresis is often performed at a doctor’s office. However, you may be able to perform the treatments at home if you purchase the machine. The treatment process is fairly simple.

You’ll place the affected body part in a basin of water. Your doctor or another healthcare provider will then turn on the machine and increase the current until you feel a slight tingling sensation on your skin. This shouldn’t cause any pain.

Iontophoresis for Hyperhidrosis

Most iontophoresis sessions for hyperhidrosis last 25 to 45 minutes. However, you’ll likely need more than one session to notice a change in your symptoms. Some people with hyperhidrosis require treatments on a regular basis. Your doctor will schedule a series of sessions based on your symptoms. They may recommend that you buy a portable machine to use at home.

Iontophoresis for a Sports Injury

When being used as a treatment for a sports injury, iontophoresis is always performed at a doctor’s office. Your doctor or another healthcare provider will add an anti-inflammatory medication to a basin of water, and you’ll place the injured area in the water. Then, your doctor will apply a mild electrical current to the medicated water. You’ll feel a tingling sensation from the electrical current, but it shouldn’t be painful.

Most iontophoresis sessions for sports injuries last 10 to 15 minutes. Your doctor may order several sessions per week until your injury begins to heal.

What Are the Side Effects of Iontophoresis?

Iontophoresis is a safe and painless procedure. Some people may experience side effects as a result of iontophoresis, but the effects usually aren’t serious. The most common side effect is dryness of the skin. Blistering, peeling, and irritation might also occur on the skin. However, these side effects can usually be treated by applying moisturizer to the skin after each session. An over-the-counter hydrocortisone cream can also make you more comfortable.

How Effective Is Iontophoresis?

Iontophoresis is generally effective in treating hyperhidrosis. People often undergo 20- to 40-minute treatment sessions several times per week until sweating decreases to a desirable level. At that point, treatments are scheduled less frequently, usually about once per week. Iontophoresis treatments must be done regularly and before sweating increases to maintain results.

Ongoing iontophoresis treatments for sports injuries are only needed until an injury begins to heal. Most people with sports injuries undergo a handful of five- to 10-minute treatment sessions over the span of a week or two to promote healing. After that point, physical therapy, rest, and proper nutrition will continue the healing process.