IONTOPHORESISReading: Cameron pgs 272-276

• Use of Direct Current to facilitate delivery of Use of Direct Current to facilitate delivery of ions into the skin for therapeutic purposes.ions into the skin for therapeutic purposes.

• Mechanism of delivery:Mechanism of delivery:““LIKE CHARGES REPEL”LIKE CHARGES REPEL”

Positive Electrode (anode) delivers (+) ions

Negative Electrode (cathode) delivers - ions

Historical Highlights

• Concept first developed & researched Concept first developed & researched over a century ago.over a century ago.

• Therapeutic use for more than 70 years.Therapeutic use for more than 70 years.• Popularity & usage was declining until Popularity & usage was declining until

Joseph Kahn Joseph Kahn PhD,PTPhD,PT had 9 publications had 9 publications from 1973 to 1983. from 1973 to 1983.

• Most case studies & clinical commentariesMost case studies & clinical commentariesKahn, J. Case Report: Lithium lontophoresis for Gouty Arthritis. Kahn, J. Case Report: Lithium lontophoresis for Gouty Arthritis. J Orthop Sports Phys Ther J Orthop Sports Phys Ther 1982;4(2):113-114.1982;4(2):113-114.

Contemporary Use• In PT: primarily for treating localized In PT: primarily for treating localized

inflammatory conditions in superficial inflammatory conditions in superficial tissues tissues – Use corticosteroids, Use corticosteroids,

(usually dexamethasone)(usually dexamethasone)

• Multiple uses of other non-steroidal ions Multiple uses of other non-steroidal ions both within & outside PTboth within & outside PT

• Ex: Dentistry, Dermatology, Emergency Ex: Dentistry, Dermatology, Emergency Dept, OphthalmologyDept, Ophthalmology

Ionto: Advantages over injection

• non-invasive; less risk of infectionnon-invasive; less risk of infection

• less pain & anxietyless pain & anxiety

• less drug into systemic circulation; less drug into systemic circulation; decreased side effectsdecreased side effects

• Less risk of local collagen Less risk of local collagen catabolismcatabolism**

* * assuming use of corticosteroidassuming use of corticosteroid

Ionto: Advantages over drug PO

• avoids “first-pass” elimination by avoids “first-pass” elimination by liver.liver.

• less drug into systemic circulation; less drug into systemic circulation; decreased side effects.decreased side effects.

• potentially greater concentration of potentially greater concentration of drug in the target area drug in the target area

• supervisedsupervised; maximizes compliance.; maximizes compliance.

Ionto: Disadvantages• risk skin irritation or burnrisk skin irritation or burn• depth of penetration known to vary b/c of depth of penetration known to vary b/c of

variation of current density, skin impedence, variation of current density, skin impedence, skin/fat thickness, and ionization/pHskin/fat thickness, and ionization/pH

• greater risk of local collagen catabolism than greater risk of local collagen catabolism than oral administrationoral administration**

• Action of drug – localized Action of drug – localized immunosuppressionimmunosuppression**

* assuming use of corticosteroid* assuming use of corticosteroid

Treatment Parameters(when using a DC stimulator eg. “dose

controller”)• Current: DC; “high current, short duration”Current: DC; “high current, short duration”

• Amplitude: 0.5 to 4.0 mA is the rangeAmplitude: 0.5 to 4.0 mA is the range

• depends on pt. tolerance, polarity, electrode sizedepends on pt. tolerance, polarity, electrode size

• Dosage: 40 to 80 mA-minDosage: 40 to 80 mA-min

• Dosage Formula: amplitude X time = mA minDosage Formula: amplitude X time = mA min

• Time: calculated by the unit, you set the dosageTime: calculated by the unit, you set the dosage

• The dispersive pad should be put The dispersive pad should be put about 6 inches away from the active about 6 inches away from the active pad on the same side of the body. pad on the same side of the body. 

Parameters cont. . . • Polarity – use the Polarity – use the same polaritysame polarity as the drug ion as the drug ion• Rx frequency: every other day at the mostRx frequency: every other day at the most

• steroid effects can be delayed & last steroid effects can be delayed & last several daysseveral days

• allows time for skin to recoverallows time for skin to recover• minimize risk of side effectsminimize risk of side effects• cost effectivecost effective

• Rx number: 4 - 7 maxRx number: 4 - 7 max• More than 7 treatments in a short period of More than 7 treatments in a short period of

time can produce detrimental effects such as time can produce detrimental effects such as skin and connective tissue break-down. skin and connective tissue break-down.

Parameters cont. . .

• Due to continuous stim using Due to continuous stim using DC, no need for dealing with:DC, no need for dealing with:– WaveformWaveform– Ramp-surgeRamp-surge– FrequencyFrequency– WidthWidth– Amplitude, Time, & Polarity abideAmplitude, Time, & Polarity abide

Treatment Guidelines (Skin Safety)

• Amplitude: the patient feels a slight tingling, itching Amplitude: the patient feels a slight tingling, itching or mild stinging.  Check the skin under both or mild stinging.  Check the skin under both electrodes after ~ 5 minutes. electrodes after ~ 5 minutes. 

• Mildly red skin under the electrodes is a Mildly red skin under the electrodes is a normal reaction normal reaction due to vasodilation & heat buildup.  due to vasodilation & heat buildup. 

• DC can cause mast cells to release histamine = DC can cause mast cells to release histamine = small bumps/vesicles and maybe petechiae. small bumps/vesicles and maybe petechiae. These reactions are normal and resolve These reactions are normal and resolve within hours.within hours.

• If the skin is bright red or if many small vesicles are If the skin is bright red or if many small vesicles are forming, should decrease the amplitude and checkforming, should decrease the amplitude and check skin again after a few minutes.  In some cases, skin again after a few minutes.  In some cases, may terminate may terminate

Many factors affect skin reaction

• The patient's skin type & sensitivity to DC The patient's skin type & sensitivity to DC currentcurrent

• Current density: not > 0.5 mA/cmCurrent density: not > 0.5 mA/cm22

• Heat build-up; Chemical build-upHeat build-up; Chemical build-up• Skin pigmentation: skin response harder Skin pigmentation: skin response harder

to judge.to judge.

Skin safety cont..

• Caution you about increasing the Caution you about increasing the amplitude after accommodation amplitude after accommodation occurs. occurs. – Counterbalance with repeated skin Counterbalance with repeated skin

checkschecks

• Some clinicians end the treatment by Some clinicians end the treatment by application of a skin lotion containing application of a skin lotion containing lanolin or aloe vera. lanolin or aloe vera.

Contraindications & Precautions

• E-stim standard contraindications & E-stim standard contraindications & precautions applyprecautions apply

• Pt. allergic to ions/drugs Pt. allergic to ions/drugs • Impaired skin sensation is a precautionImpaired skin sensation is a precaution• No thermal modalities immediately before or No thermal modalities immediately before or

after. after. Why??Why??• No conductive gel before Ionto. No conductive gel before Ionto. Why??Why??• Diabetes is a precaution due to decreased Diabetes is a precaution due to decreased

peripheral sensation and secondary to peripheral sensation and secondary to localized immunosuppression caused by localized immunosuppression caused by corticosteroid. corticosteroid.

Most Common Ion in PT

• Dexamethasone Sodium PhosphateDexamethasone Sodium Phosphate• 0.4% aqueous solution0.4% aqueous solution

• 0.4% = 0.004 g/ml = 4 mg/ml0.4% = 0.004 g/ml = 4 mg/ml

• corticosteroid for anti-inflammatorycorticosteroid for anti-inflammatory• effects; polarity is (-)effects; polarity is (-)

Additional Ions(know name, polarity, usage)

• Acetic Acid (-) dissolve Ca depositsAcetic Acid (-) dissolve Ca deposits• Calcium Chloride (+) ms. relaxantCalcium Chloride (+) ms. relaxant• Hyaluronidase (+) disperse edema; not acuteHyaluronidase (+) disperse edema; not acute• Iodine (-) softens adhesions & scar tissueIodine (-) softens adhesions & scar tissue• Magnesium Sulfate (+) ms. relaxantMagnesium Sulfate (+) ms. relaxant• Sodium Salicylate (-) ms. & joint painSodium Salicylate (-) ms. & joint pain• Lidocaine (+) local anestheticLidocaine (+) local anesthetic

• Example Example pharmacy services

Equipment & Supplies

• Drug ion dissolved in aqueous solution or Drug ion dissolved in aqueous solution or suspended in ointmentsuspended in ointment

• Absorbent & buffered electrodeAbsorbent & buffered electrode• Iontophoresis devicesIontophoresis devices

• Dupel DC stimulator by EMPI is what we will useDupel DC stimulator by EMPI is what we will use– Numerous other brands of DC stimulators existNumerous other brands of DC stimulators exist

• Patch products: Iontopatch, ActionPatch Patch products: Iontopatch, ActionPatch • Newest – Hybresis by EMPINewest – Hybresis by EMPI

Dupel by EMPI

Phoresor II and look-a-likes

• Current: DC, “low current, long duration”Current: DC, “low current, long duration”• Amplitude: ~0.2 mA and less (if constant voltage)Amplitude: ~0.2 mA and less (if constant voltage)

• Dosage: 40 to 80 mA-minDosage: 40 to 80 mA-min– more convenient for clinicians and perhaps more convenient for clinicians and perhaps

patients because in-clinic wear time is greatly patients because in-clinic wear time is greatly decreased. Efficacy??decreased. Efficacy??

Patch (Integrated) Systems

Iontopatch by Birch Medical

Action Patch by EMPI

HYBRESIS by EMPI

Effectiveness Factors

• Dosage: mA-minDosage: mA-min• Little evidence exists that different Little evidence exists that different

combinations of amplitude & duration provide combinations of amplitude & duration provide equivalent amounts of ion transfer; some equivalent amounts of ion transfer; some evidence that 4mA X 10 min is best. 40 evidence that 4mA X 10 min is best. 40 mAmin is a commonly accepted standard.mAmin is a commonly accepted standard.

• Preparation of skinPreparation of skin• must be clean; no competing ions.must be clean; no competing ions.

• Depth of target tissueDepth of target tissue• skin thickness, fat layer, overlying tissuesskin thickness, fat layer, overlying tissues

• Electrode ContactElectrode Contact

Depth of ion penetration• Believed to occur primarily thru pores Believed to occur primarily thru pores

(sweat & oil) & hair follicles(sweat & oil) & hair follicles• Passsive diffusion and local circulation Passsive diffusion and local circulation

are required to shuttle the drug deeper, are required to shuttle the drug deeper, to the cells of the target tissueto the cells of the target tissue

• Research – effect is often inferred Research – effect is often inferred based on clinical effectiveness based on clinical effectiveness (pain, (pain, ROM, MMT, function)ROM, MMT, function)

• max depth of ion penetration is largely max depth of ion penetration is largely unknown in humans unknown in humans (8-10mm in mammals)(8-10mm in mammals)