24: Dermatology Therapeutics - Frush Flashcards
percutaneous absorption variables
- concentration more important than volume
- lipophilicity
- molecular size (most effective topical meds have molecular weight of less than 1000)
strongest percutaneous absorption vehicle
ointment
- solution is typically the weakest
will inflamed skin increase or decrease absorption?
increase
indications for open wet dressings
acute inflammatory conditions, erosions and ulcers
- causes vasoconstriction and decreased inflammation
- closed wet dressings can cause maceration
- used to reduce moisture, maceration, and friction
- suspension of powder in water
- semisolid emulsion of oil in water
- semisolid emulsion that liquefies on contact, leaving thin film
- water deroplets suspended in oil or petroleum
- powders
- lotions
- cream
- gel
- ointment
clinical comparisons of various vehicles
FTU
fingetip unit
- ointment expressed from tube from index finger MPJ to tip of finger
- approx 0.5 g
- 1 ftu should cover plantar aspects of 1 or both feet
- need 2 ftu to cover one foot
antibiotic solutions used for soaking
dakin’s
- sodium hypochlorite aka bleach
acetic acid
- drying, good for wet tinea pedis, effective against sueprficial pseudomonas infections
burrow’s
- aluminum acetate solutions, dry out wounds
epsom salt
- magnesium sulfate, drying effect
Bacitracin
▪Good Gram (+) coverage
▪Minimal to no gram (-) coverage
▪Can cause sensitivity reaction, particularly with stasis dermatitis
Polysporin
- Contains 2 abx – bacitracin and polymyxin B
- PolymyXin B effective against gram (–)
- Including pseudomonas
- Contact allergy rare
Neosporin
Contains 3 abx – bacitracin, polymyxin B, and neomycin
Neomycin – covers gram (+) and (-)
▪Good S. aureus coverage
▪Does not cover Pseudomonas, or Bacteroides
▪Weak Strep activity
▪1% of population has contact allergic sensitivity, rate can increase to almost 10% in patients with prolonged use
▪Bacitracin causes coreaction with neomycin
Can be used in nasal passages for MRSA carriers
mupirocin (bactroban)
gentamicin
good gram - coverage, notably pseudomonas
silvadene
- Effective against Gram (+) and (-)
- Shouldn’t use in patients allergic to sulfonamides
- If using in large area over long time period, can get significant absorption of silver
- Can occasionally cause brown/gray hyperpigmentation of skin with use
- Commonly used with burn patients
used for presurgical scrub for surgeon and/or patient
topical antiseptics
- chlorhexidine
- povidone-iodine