Compounding pharmacies offer a variety of solutions for iontophoresis treatments.
Iontophoresis is a noninvasive process that uses locally applied direct current to increase the diffusion of certain water-soluble, low-molecular-weight, ionic molecules across intact skin. This safe and effective process pushes medication into surface tissues at a depth of 1–3 cm.
The electrode with the same charge as the ions repels the similarly charged ions. Medications listed as negative polarity are dispersed from the negatively charged electrode (black lead wire).
Iontophoresis is a useful and effective alternative to injections, oral medications, and transdermal gels or patches. Iontophoresis provides a relatively painless option for patients who are reluctant to receive injections. It minimizes the potential for tissue trauma from injections, and it has few side effects.
Commonly Used NSAIDs for Inflammation
Dexamethasone, known as the “gold standard,” is a glucocorticoid medication used to treat acute and chronic inflammatory conditions such as tendinitis, bursitis, and lateral epicondylitis. Dexamethasone sodium phosphate 0.4% (negative polarity) has been the traditional drug of choice for iontophoresis, but this trend appears to be changing.
Ketoprofen 10% (negative polarity) is the nonsteroidal anti-inflammatory medication (NSAID) used most often to treat inflammation and pain. Like dexamethasone, ketoprofen is used three times per week to treat acute or chronic musculoskeletal conditions. Ketoprofen is an excellent alternative when corticosteroids are ineffective or contraindicated. Beneficial effects with NSAIDS occur within three or four treatments and are considered safe if used for several weeks.
Diclofenac Sodium 1% (negative polarity) and Naproxen Sodium 2% (negative polarity) are other NSAIDS that are used three times per week. They are similar to ketoprofen.
Sodium Salicylate 2% (negative polarity) is similar to aspirin and helps to control pain and inflammation. It is an alternative to dexamethasone, diclofenac, and ketoprofen, but it is rarely used.
Other Commonly Used Medications
Acetic Acid 4% (negative polarity) can help resolve acute or chronic soft-tissue calcific mineralization associated with heel spurs, calcific tendinitis, and myositis ossificans. The negatively charged acetate ion combines with the relatively insoluble calcium carbonate to form the soluble compound calcium acetate. Treatments are administered three times per week for 3–8 weeks.
Gabapentin 4% (negative polarity) helps relieve neuropathy. Treatments are administered up to three times per week based on symptom severity.
Potassium Iodide 10% (negative polarity) is a sclerolytic used to decrease scar tissue and release tendon adhesions. It allows the treatment area to be stretched and molded, and it can increase range of motion. Treatments are administered three times per week for 1–3 weeks.
Lidocaine 4% (positive polarity) is a local anesthetic that produces numbness and temporary pain relief. It provides symptomatic relief, but it does not treat the underlying cause of pain. Treatments are administered on an as-needed basis.
Magnesium Sulfate 2% (positive polarity) is used to help relieve acute muscle spasm, neuralgia, and stiffness. It decreases excitability of skeletal muscle and slows nerve transmission. Treatments are administered on an as-needed basis.
Lithium 3% (positive polarity) treats gout and gouty arthritis. Lithium alters sodium urate crystal formations in the large toe to form soluble lithium urate.
Treatments are administered once daily for 2–5 days or until the patient is asymptomatic.
Rarely Used Iontophoresis Solutions
• Atropine Sulfate 0.001%–0.01%
• Calcium Chloride 2%
• Copper Sulfate 2%
• Estriol 0.3%
• Gentamicin Sulfate 0.8%
• Glycopyrrolate 0.05%
• Hyaluronidase 150 units/ml
• Ketorolac 0.6%
• Mecholyl Chloride 0.25%
• Morphine Sulfate 0.2–0.4%
All iontophoresis treatments have the potential to cause local irritation, histamine reaction, or burning at the treatment site. Clinicians should monitor patients for adverse reactions, and should notify physicians and the pharmacy if adverse reactions occur.
Finding a Compounding Pharmacy
The pharmacists and technical staff at chain pharmacies fill traditional prescriptions and are usually not experienced with compounding medications. The pharmacists and staff of compounding pharmacies are specially trained in the art and science of preparing custom dosage forms, such as iontophoresis solutions.
A physical therapist should consider the following criteria when seeking a potential source for pharmaceutically compounded medications:
• references from other rehabilitation clinicians;
• references from vendors and sales representatives of companies that provide iontophoresis devices and electrodes;
• knowledgeable pharmacy staff who can answer clinical treatment questions;
• appearance in national and regional physical therapy trade journals;
• attendance at and support of national and regional physical therapy association trade shows; and
• membership in compounding trade associations such as International Association of Compounding Pharmacist, American College of Apothecaries, or Professional Compounding Centers of America.
Ordering Requirements
Iontophoresis solutions require a prescription. Most state boards allow physical therapy clinics to have stock bottles of iontophoresis solutions to use in the clinic. In these cases, the clinic medical director or physician can write a prescription for the drug solution, strength, and quantity; and the directions for clinic use.
These prescriptions would customarily be billed to and shipped to the physical therapy clinic.
Patient-Specific Prescriptions
Some practice settings and a few state boards require physicians to write iontophoresis prescriptions for individual patients. Patient-specific prescriptions are written for a small container or a specific number of doses of iontophoresis solution for a specific patient for use at a specific clinic.
Patient-specific prescriptions can be billed to and/or shipped to the clinic or the patient’s home. Many clinics prefer the pharmacy to bill the patient directly. Most insurance companies will reimburse the patient directly.
Additional Research Needed
Much of the published literature references for iontophoresis treatment involve individual case reports, small-scale studies, anecdotal experiences, and clinical impressions. Documentation of treatment successes and failures for individuals is helpful, but multicentered, evidence-based studies measuring specific outcomes are needed to conclusively prove the efficacy of iontophoresis. Although few evidence-based studies have been published, an overwhelming majority of patients are experiencing positive clinical outcomes.
Jay Watts, RPh, FACA, is the owner and pharmacist at Aiken Compounding Pharmacy in Aiken, SC, and a regional director for the American College of Apothecaries. He can be reached at jaywatts@aol.com.
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