Iontophoresis

Question 1

What is iontophoresis?

Answer 1

facilitate transdermal delivery of drugs

Question 2

What current is used with iontophroesis?

Answer 2

low amplitude direct current

Question 3

What is local delivery of drugs?

Answer 3

delivery into tissue directly below electrode

Question 4

What is systemic delivery of drugs?

Answer 4

delivery of drugs throughout the body

Question 5

What medication is most frequently used in iontophoresis?

Answer 5

dexamethasone

Question 6

What is the depth of penetration for iontophoresis?

Answer 6

3-20mm

Question 7

What is the depth of penetration of passive delivery of medication?

Answer 7

2-4mm

Question 8

What must the current amplitude by in iontophoresis?

Answer 8

current must be high enough to overcome combined resistance of electrode and skin

Question 9

What is the current amplitude of iontophoresis?

Answer 9

1 mA-4mA

Question 10

How is dosing of iontophoresis determined?

Answer 10

dose described as charge in mA per min (milliamps of current per total time of current)

Question 11

What are the most common doses of iontophoresis?

Answer 11

40 mA/per and 80 mA per min

Question 12

What are some adverse effects of direct current?

Answer 12

electrothermal burn

electrochemical burn

Question 13

How can an electrothermal burn occur?

Answer 13

high amounts of DC pass thru insulator of skin and can heat skin up
strong DC heat skin and create thermal burn

Question 14

What kind of burn is more likely?

Answer 14

electrochemical burn

Question 15

What can form inside the body?

Answer 15

acid and base reaction

Question 16

What can build under the positive electrode?

Answer 16

acid

Question 17

What can build under the negative electrode?

Answer 17

base- more damaging of the two

Question 18

How are adverse effects minimized in iontophoresis?

Answer 18

1. increase size of negative electrode
2. decrease current amplitude or current density
3. buffer electrodes

Question 19

What are battery operated patch electrodes?

Answer 19

very low voltage
very long time (.1mA for 12 hours)
may not overcome skin resistance

Question 20

What kind of drugs are acceptable to use in iontophoresis?

Answer 20

ionic
stable in solution
ions not altered by electric current
ions are small or moderate in size

Question 21

Why should ions by small or moderate in size for iontophoresis to work?

Answer 21

because it has to be small enough to be pushed through pores into subcutaneous tissue

Question 22

Where is the electrode placed in iontophoresis?

Answer 22

drug delivery electrode placed over pathology

Question 23

What is the max current density at the cathode?

Answer 23

0.5mA/cm2

Question 24

What is the max current density at the anode?

Answer 24

1.0mA/cm2

Question 25

What is twice the size rule?

Answer 25

the negative electrode is twice the size of the positive

Question 26

What should the polarity be?

Answer 26

Polarity of drug delivery electrode should be same as polarity of ionic drug

Question 27

What should the current amplitude be for iontophoresis?

Answer 27

Highest that is comfortable to patient

Should not exceed 4 mA

Question 28

What should the treatment time be for iontophoresis?

Answer 28

Calculated after treatment amplitude is determined

Determined by desired dose (generally 40 mA*min)

Question 29

What is combo?

Answer 29

current and ultrasound
Many high volt pulsed current stimulators offer the possibility of combining electric stimulation with ultrasound during a single treatment

Question 30

What is the underlying idea of combo?

Answer 30

idea is that you can possibly get an additive or combined therapeutic effect by using the two simultaneously