iontophoresis

Question 1

what is iontophoresis

Answer 1

transdermal drug delivery using low voltage DC to move ions across a dermal barrier

Question 2

what’s the most likely mechanism of iontophoresis

Answer 2

increase in permeability of corneum stratum

Question 3

iontophoresis depth of penetration

Answer 3

3-20mm

Question 4

iontophoresis depth of penetration mechanism

Answer 4

• may be linked to type of molecular structure being moved
• medication is placed in aqueous solution to dissociate into (+) and (-) ions
• low volt DC can then use polarity to move these ions

Question 5

3 mechanisms of ion transfer

Answer 5

• electromigration
• electroporation
• electroosmosis

Question 6

what is electroporation

Answer 6

increase in porosity of epidermis in response to e-stim

Question 7

what is electromigration

Answer 7

movement of ions into tissue; based on “volume flow” and not just diffusion

Question 8

what is electroosmosis

Answer 8

• human skin has a net (-) charge
• ions moving from (+) to (-)
• so for (+) charged ions this may enhance the delivery of ions as they are “going with the flow” and hinder movement of (-) ions

Question 9

what is the driving force behind iontophoresis?

Answer 9

repulsion of like charges

Question 10

positively charged ions are repelled by what

Answer 10

by the positive pole (anode)

Question 11

negatively charged ions are repelled by what

Answer 11

by the negative pole (cathode)

Question 12

treatment time for iontophoresis

Answer 12

20mA min - 160mA min
- 40 mA min and 80 mA min are most common

Question 13

what will drive the time for iontophoresis treatment?

Answer 13

intensity (mA)
- intensity to tolerance (most units do not exceed 4mA)

Question 14

1 mA current treatment parameters

Answer 14

treatment time: 40
dose (mA.mins): 40

Question 15

2 mA current treatment parameters

Answer 15

treatment time: 20
dose (mA.mins): 40

Question 16

3 mA current treatment parameters

Answer 16

treatment time: 13.3
dose (mA.mins): 40

Question 17

4 mA current treatment parameters

Answer 17

treatment time: 10
dose (mA.mins): 40

Question 18

cathode skin reaction

Answer 18

• sodium hydroxide can form under the cathode
• caustic

Question 19

anode skin reaction

Answer 19

hydrochloric acid can form under the anode

Question 20

is the anode or cathode known as the “alkaline reaction”?

Answer 20

cathode

Question 21

is the anode or cathode known as the “acidic reaction”?

Answer 21

anode

Question 22

is the alkaline reaction or acidic reaction more comfortable

Answer 22

acidic reaction is less uncomfortable

Question 23

current density for the cathode (-)

Answer 23

should not exceed 0.5 mA/cm2

Question 24

current density for the anode (+)

Answer 24

should not exceed 1.0 mA/cm2

Question 25

is iontophoresis a bipolar or monopolar set up?

Answer 25

monopolar

Question 26

active electrode placement

Answer 26

- (+) or (-) based on medication type - electrode size is smaller - place directly over treatment area

Question 27

dispersive electrode placement

Answer 27

- opposite of active - electrode size is larger - place at a distance from active (usually proximal)

Question 28

acetic acid (acetate) polarity and purpose

Answer 28

- polarity: (-) - purpose: calcium deposits

Question 29

dexamethasone polarity and purpose

Answer 29

- polarity: (-) - purpose: inflammation

Question 30

iodine polarity and purpose

Answer 30

- polarity: (-) - purpose: scars

Question 31

lidocane polarity and purpose

Answer 31

- polarity: (+) - purpose: anesthetic

Question 32

iontophoresis precautions and contraindications

Answer 32

stimulation across chest, pacemakers, over carotid sinuses in neck, uncontrolled hypertension, PVD, thrombophlebitis, pregnancy, impaired sensation, confused patients, uncontrolled seizures, obesity, cancer

Question 33

iontophoresis treatment procedure

Answer 33

- select appropriate medication for condition - inspect skin for cuts, abrasion, scars, etc - check sensation - check for other contraindications/precautions - instruct patient about treatment (why, how it works, what to expect)

Question 34

iontophoresis treatment procedure set-up

Answer 34

- position pt for comfort - clean and prep skin - prepare active electrode by placing medication on pad with syringe - place active electrode over treatment area - place dispersive electrode at a distance from active

Question 35

iontophoresis treatment procedure cont.

Answer 35

- connect lead wires - turn on device - set dosage (mA.min) - allow ramp of intensity if indicated by unit - turn up intensity based on pt tolerance - terminate treatment and remove electrodes

Question 36

whats the most important thing to do once you're finished with the treatment?

Answer 36

INSPECT THE SKIN