06-10: Iontophoresis

Question 1

Definition of iontophoresis

Answer 1

• E-Stim used to drive medications transdermally into the body
• Direct current (DC): set active electrode; monopolar
• Medication separated into ions based on polarity

Question 2

Acidic skin reaction (sclerotic)

Answer 2

• Skin becomes hardened over time

Question 3

Alkaline skin reaction (sclerolytic)

Answer 3

• Skin becomes soft over time

- Increases risk of irritation and burn during treatment

Question 4

Buffering technique

Answer 4

• Buffering agent (saline) placed in the electrode pad that covers the drug reservoir (Dispersive pad)
• Prevents significant pH changes of skin
• Medication on active pad

Question 5

Electrolysis

Answer 5

• Breakdown of the medication when E-Stim is passed through the molecule

Question 6

Electron exchange

Answer 6

• Exchange of electrons between the electrode and the medication

Question 7

Redox reaction

Answer 7

• Breakdown of water as E-Stim passes through the molecule; H+ collects under anode; OH- collects under cathode

Question 8

Parameters of Iontophoresis

Answer 8

• Polarity: Same as medication
• Electrode Size: Negative electrode (cathode) is twice size as positive electrode (anode), regardless of which one is active
• Electrode Placement: Active - over target area; Dispersive - far from active
• Intensity: Slowly increase, max 5 mA
• Rx time: 15-20 min.

Question 9

Electrodes

Answer 9

• Active: Electrode containing medication; Also termed treatment or delivery
• Inactive: Other electrode completing the circuit, not containing medication; Also termed reference or dispersive

Question 10

Dosing Equation

Answer 10

• Dosage (mA.min) = Current (mA) x Duration (min)
• Dosage Ranges: 20-80 mA.min
• Amplitude: 0.1 - 4 mA
• Ex: 40 mA.min = 4 mA x 10 min

Question 11

Indications for Iontophoresis

Answer 11

• Inflammation
• Neuralgia
• Edema
• Ischemia (ulcers)
• Hyperhidrosis
• Plantar warts
• Gout
• Calcific Tendonitis
• Keloids (scars)

Question 12

Contraindications for Iontophoresis

Answer 12

• Cardiac pacemakers
• Pregnant uterus
• Known Hx of miscarriage
• Carotid sinus
• PVD
• Phrenic nerve, eyes or gonads
• Osteomyelitis
• Hemorrhage

Question 13

Positive Charge Medications

Answer 13

• Antibiotics: Suppurative ear chondritis
• Calcium: Spasmodic conditions, tics, “snapping fingers” (joints)
• Copper: Allergic rhinitis, sinusitis, athlete’s foot
• Hyaluronidase: Localized edema
• Hydrocortisone*: Anti-inflammatory
• Histamine
• Lidocaine*: Acute inflammatory conditions (bursitis, tendinitis, tics, TMJ)
• Lithium: Gouty tophi, hyperuricemia
• Magnesium: Muscle relaxant, vasodilator, mild analgesic
• Mecholyl: Vasodilator, muscle relaxant, analgesic
• Priscoline: Indolent ulcers
• Zinc: Open lesions and ulcerations

Question 14

Negative Charge Medications

Answer 14

• Acetate: Sclerolytic exchange ion with calcific deposits
• Chlorine: Scar tissue, keloids, burns
• Citrate: Rheumatoid arthritis
• Dexamethasone*: Musculoskeletal inflammatory conditions
• Iodine: Adhesive capsulitis, scars
• Salicylate: Decongestant, sclerolytic, anti-inflammatory agent; Frozen shoulder, scar tissue, warts, other adhesive or edematous conditions

Question 15

Postive/Negative Charge Medications

Answer 15

• Ringer’s solutions: Open decubitus lesions

- Tap water: Hyperhidrosis