Iontophoresis Notes Flashcards
What is iontophoresis?
a therapeutic technique that involves the introduction of ions into the body tissues by means of a DC
What is the difference between iontophoresis and phonophoresis?
Phono = involves the use of acoustic energy in the form of US to drive whole molecules across the skin into the tissues Ionto = uses an electrical current to transport ions into the tissues
How does transdermal iontophoresis compare to a passive skin application?
- Decreases absorption lag time
- Increases delivery rate
- Can deliver spiked and sustained release
What is the benefit of delivering spiked and sustained release?
Reduces the possibility of developing a tolerance to the drug
How does iontophoresis ensure that the plasma concentration is within the therapeutic window?
Delivers medication at a constant rate
What determines the rate at which an ion is delivered?
concentration of the ion pH of the solution molecular size of solute current density duration of treatment
What are the advantages of ionto to oral medications?
Concentrated in a specific area
Does not have to be absorbed in the GI tract
What is the cathode?
The electrode that has the greatest concentration of electrons, negatively charged
Which type of movement creates an acidic reaction? Alkaline?
Acidic = negative to positive Alkaline = positive to negative
What is the anode?
Electrode with a lower concentration of electrons
Which reaction is more likely to produce tissue damage?
Akaline
The force that acts to move ions through the tissues is determined by…
strength of the electrical field (current density)
electrical impendence of tissues to current flow
What determines ion migration?
the difference in current density between the active and inactive electrode
How can current density be altered?
- changing the size of the electrode
- increasing current density
- decreasing current intensity
Which electrode is recommended to be larger?
The negative electrode
What do sweat glands do in terms of conduction?
Decrease impedance,
How far does medication penetrate?
no more than 1.5 cm over a 12-24 hour period, only 1-3 mm during average 15 minute treatment
The quantity of ions transferred into tissues is determined by….
Intensity of current
Current density at active electrode
Duration of current flow
Concentration of ions in solution
How can ion transfer be increased?
Increasing intensity
Increasing duration of treatment
What is the hazard of increasing treatment duration?
skin impedance decreases, increasing likelihood for burns
What type of current does ionto use?
Continuous direct current, ensures unidirectional flow
What type other type of current is being research for ionto?
AC, may help avoid burns and increase drug delivery
What is the range for the current density used?
0.1 mA/cm2 - 0.5 mA/cm2 of the active electrode used
What is the treatment duration?
10-20 minutes, 15 minute average
What is current amplitude measured in?
milliampere minutes (mA minutes)
What is the most effective current amplitude dosage?
40 mA-minutes
can range from 40-80
How is mA-min calculated?
2 mA current x 15 minute treatment = 30 mA-min dose
Describe the setup for the active electrode
Receives the medication, lead wire attached has same polarity as the ion solution
How far should electrodes be placed?
at least the diameter of the active electrode
Source, polarity, indications, concentration for:
Acetate
Source: acetic acid
Polarity: negative
Indications: Calcium deposits, inflammation
Concentration: 2.5-5%
Source, polarity, indications, concentration for:
Dexamethasone
Source: DexNa2PO3
Polarity: negative
Indications: inflammation
Concentration: 0.4%
Source, polarity, indications, concentration for:
Lidocaine
Source: lidocaine
Polarity: positive
Indications: local anesthetic
Concentration: 5%
Source, polarity, indications, concentration for:
Tap water
Source: n/a
Polarity: neg/pos
Indications: hyperhidrosis
Concentration: n/a
Source, polarity, indications, concentration for:
Salicylate
Source: NaSal
Polarity: negative
Indications: Inflammation, plantar warts
Concentration: 2%
What are the indications for ionto?
inflammation analgesia ischemia edema calcium deposits scar tissue hyperhidrosis fungi open skin lesions herpes allergic rhinitis gout burns RSD
What are the contraindications for ionto?
Skin sensitivity reactions
Sensitive to aspirin (salicylates) or ions used
Gastritis or active stomach ulcer (hydrocortisone)
Asthma (mecholyl)
Sensitive to metals (zinc, copper, magnesium)
Sensitivity to seafood (iodine)
Precautions
Unknown patient allergies Cardiac disease Impaired mentation/dementia Malignant tumor Open wounds Skin irritation After using other physical agents
Side effects
Erythema
Itching, tingling, burning
Minimal blistering
What are some conditions that ionto can be used for?
Inflammation Lateral epicondylitis Hyperhidrosis Anesthetic Plantar fasciitis Patellar tendonitis
What is hyperhidrosis? How much of the population does it effect?
Increased sweat production
.6-1% of population
What causes hyperhidrosis?
Over excitability of sympathetic, cholinergic fibers that innervate eccrine glands
What are treatment options for hyperhidrosis?
Ionto - tap water or anti-cholinergics
Botulinum toxin A
Surgery
What are the benefits of using ionto as an anesthetic?
- negates pain (inconvenience of injections)
- prevents variation in absorption seen with orals
- reduces chance of over/under dose
- can deliver drugs with short half lives
- simple to use and terminate
What ion is associated with a sensitivity to aspirin?
Salicylate
What ion is associated with a sensitivity to metal?
Zinc, Copper, Magnesium
What ion is associated with a sensitivity to seafood?
Iodine
What ion is associated with asthma?
Mecholyl
What ion is associated with gastritis or stomach ulcers?
Hydrocortisone
