Iontophoresis

 

Iontophoresis is the transfer of ions. Iontophoresis may have begun as early as 1747 with Pivati, however it was Le Duc who become widely recognized for it's use in the early 1900's. Le Duc used cyande, a negative ion, under a cathode and strychnine, a positive ion which causes convulsions, under the anode. When he touched two rabbit's heads together, he could administer the dose of consulsant to one rabbit and see the other one convulse. Clinically, it was first used by Ishashi in 1936 utilizing tap water as a therapy for hyperhydrosis. Now, iontophoresis is widely used for medicine, surgery, dentistry and rehab. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iontophoris uses a continuous, direct current to deliver ions across the skin and into systemic circulation with the idea that "like repels like". A negatively charged therapeutic ion will be placed under its matched negative electron and will be repelled away from the electron and into the skin. This can be done with positively charged therapeutic ions and matched positive electons as well. These are differentiated as anodal or cathodal iontophoresis. Whichever electrode the ions are placed is referred to as the active AKA treatment AKA delivery electrode. The other electode is referred to as the dispersive or return electrode. Costum electrodes can be made from aluminum foil, gauze or cotton impregnanted with an ionic solution at the expense of having no pH buffer and extra prep time. Alternatively, commercial pads of various materials and predetermined sizes, which are more expensive, can also be used. 

 

Physiological effects occur as a result of the capacity of current to push drug ions through the skin. The therapeutic effect depends on the specific pharmaceutical content of the ionic drug used.

 

• Acetate (-)

  • ​Calcium deposits

• Dexamethasone (-)

  • ​tissue inflammation by inhibiting prostaglandins

• Hydrocortisone (+)

  • ​prostaglandin inhibitor

• Lidocaine (+)

  • ​Decreases local pain by blocking local nerve impulse transmissions

• Tap water (+/-)

  • ​suppresses sweating of palms, soles, and armbits by inducing keratin plugs in the lumen of sweat glands

 

The skin's pH level changes under the electrode and can result in a burn. This is a major limitation regarding max dose. Buvvering has been one approach to deal with the changing pH and to prevent the burns that may result.

 

Dosimetry is dependent on the concetration of the ionic drug solution, current amplitude, and total treatment duration. 

An equation to help determine dosimetry is:

Dose (mA.min) = Amp (mA) x time (min)

• ​​EX:

  • 1 mA for 30 min

  • 2 mA for 15 min

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Indications

• Hyperhydrosis (tap water)

• plantar fasciitis (dexamethasone)

• Peyronies disease

• Musculoskeletal inflammatory disorders (dexatherasone, lidocaine)

• TMJ

 

Contraindications

• Over damaged skin and open lesions

• Known sensitivity or allergy to ions delivered

• Over skin with impaired sensation

• Over electronicimplants