EEI 10/24b Iontophoresis

Question 1

neutral atom

Answer 1

protons = electrons

Question 2

positive ion

Answer 2

protons > electrons

Question 3

negative ion

Answer 3

protons < electrons

Question 4

solvent

Answer 4

breaks down solute

-saliva is a solvent and breaks down our food

Question 5

electrophoresis

Answer 5

ionic movement according to the electrically charged current acting on it

Question 6

positive ions

Answer 6

cations

Question 7

negative ions

Answer 7

anions

Question 8

cathode

Answer 8

negative electrode

lots of cations want to stick to it

Question 9

anode

Answer 9

positive electrode

attracts negative

Question 10

three main pathways for ionto

Answer 10

1. Paracellular (between cells)
2. Transcellular (through cells)
3. Appendageal (along pores: hair follicles, sweat glands, etc)

Question 11

positives for ionto rather than injection

Answer 11

1. non-invasive
2. less risk of infection
3. more local/less systemic

Question 12

define iontophoresis

Answer 12

use of low amplitude direct current to administed ionized medications across the skin

Question 13

typical substances that travel on ionto

Answer 13

anti-inflammatories

local anesthetics

Question 14

what is the typical current range of ionto device?

Answer 14

1-4 mA

Question 15

drug delivery mechanisms

Answer 15

electrophoresis (main technique clinically)
electro-osmosis
electroporation

Question 16

define electroporation

Answer 16

process by which a large transmembrane voltage temporarily disturbs the phospholipid bilayer membranes, creating a “pore” through which molecules can pass

-within stratum corneum

Question 17

electroosmosis

Answer 17

movement of a solvent, carrying with it other dissolved substances, through the skin under the influence of direct current

-same direction as the flow of counter ions
> at physiologic skin pH (~7); skin carries a negative charge, counter ions are positive

Question 18

electro-osmosis electrodes

Answer 18

anode (+) medication = enhanced

cathode (-) medication = hindered

Question 19

advantages of iontophoresis

Answer 19

non-invasive
get local reaction, decreased systemic
painless (itching or slight tingling)
avoids tissue damage
decreases side effects - maybe

Question 20

disadvantages of iontophoresis

Answer 20

the amount that gets to the target tissue (biggest factor) is less known
can get burns from DC current

Question 21

for pain, which drug do you take and what charge is it

Answer 21

lidocaine

(+) charged

Question 22

for calcium deposits, which drug do you take and what charge is it

Answer 22

acetic acid 
(-) charged

Question 23

for inflammation, which drug do you take and what charge is it

Answer 23

dexamethasone

(-) charged

Question 24

for pain, overuse, and arthritis which drug do you take and what charge is it

Answer 24

sodium salicylates
(-) charged

Question 25

what is dexamethasone best for?

Answer 25

itises | -plantar fasciitis, lateral epicondyle, rotator cuff tendons, infrapatellar tendon, tib. post. tendon, etc

Question 26

electrochemical effects of DC current

Answer 26

AABC - acid anode, basic cathode

Question 27

what effects do DC anodes have on the body

Answer 27

Acidic caustic HCl hardens tissue accelerates tissue growth decreases nerve excitability (HYPERPOLARIZATION) increases capillary coagulation (restricts BF)

Question 28

what effects do DC cathodes have on the body

Answer 28

Basic caustic NaOH softens tissue bacteriostatic effect (keeps area clear of bacteria) increases nerve excitability (DEPOLARIZATION) promotes vasodilation

Question 29

what are the current, duration, and pH targets with cathode DC current

Answer 29

current 2-4mA duration 30 min pH change from 7 to 10.1

Question 30

medication of ionto is driven due to

Answer 30

- amplitude of current (1-4 mA) - duration of treatment (20-40 min) - total current dosage (mAxmin = 40-80mA*min) - polarity (medication dependent)

Question 31

if current density has to be less than 0.5mA/cm2, for a 2x2 electrode what is the maximum amplitude you should provide?

Answer 31

current density = current/area current = current densityxarea =2.0mA as the peak amplitude

Question 32

what happens if the maximum calculated amplitude is 6mA?

Answer 32

devices normally don't go over 4mA, so we wont utilize that current

Question 33

how do you know which dosage is best?

Answer 33

research is not there to justify one vs the other, but it depends on the patient's needs, schedule, and sensitivity

Question 34

what is the best factor to utilize with penetration of the drug into the skin?

Answer 34

TIME ELAPSED - current intensity does not matter - after 20minute treatment, leave on patch for another 5-6 hrs to continue flow

Question 35

penetration of the ions is the ___ in the region of the ___, it is in proportion to the ____ magnitude, and it is most likely deposited below the _____. Onward migration to the ___ tissues is achieved by ____ rather than being ___ ___ by the current

Answer 35

``` greatest pores current stratum corneum deeper diffusion over time driven/ionto'd deeper ```

Question 36

how to set up electrodes

Answer 36

1. active - delivery electrode, medicated 2. return - dispersive electrode (to finish circuit) 3. polarity - cathode (- lead) to deliver (-) medicine; anode (+ lead) to deliver (+) medicine

Question 37

what lead does dexamethasone go under when delivering ionto

Answer 37

cathode (-)

Question 38

what don't you want to do when delivering ionto?

Answer 38

1. ultrasound (Increases blood flow - so would be contra to the ionto) 2. heat/ice (During heat, BF increases and with Ice vessels constrict but when you take it off it triggeres BF back to tissue so it's not good!) 3. short wave diathermy (waves and heat) 4. massage 5. exercise

Question 39

what do you want to consider for the patient when delivery ionto

Answer 39

Keep the medication in the location that we want! Want to avoid increased blood flow to the area Do ionto at the end of the treatment

Question 40

clinical considerations for ionto?

Answer 40

1. drug allergies (to NSAIDs and others - contact physician) 2. size of affected area (targetted, small, and superficial; thumb>hamstring) 3. depth of penetration (increase duration) 4. contraindications and precautions (same as stim) - broken, damaged skin - reduced sensation - pacemaker, bladder stimulators, phrenic nerve stilumators

Question 41

do you directly start with 4 mA of current on a new patient?

Answer 41

No, begin with 1 or 2 then progressively crank up to 4

Question 42

possible skin reactions from ionto

Answer 42

1. mild skin reaction - not a burn; some erythema 2. small blister-like vessicles may appear and resolve in minutes to hours (if doesn't resolve, don't do treatment again) 3. abnormal response: bright white spots

Question 43

inflammation and ionto

Answer 43

use dexamethasone -> deliver with cathode for lateral epicondylitis, carpal tunnel syndrome, de Quervain synovitis, planta fascitis Side effects: - break down of collagenous tissue (muscle, tendon, bone) - don't do every day - if not effective in 3-4 treatments STOP

Question 44

what is the big risk with anesthetizing the skin with lidocaine?

Answer 44

delivered with anode, skin becomes numb, increased risk of electrical or chemical burns