Pharm For Skin 1

Question 1

Principles for topical therapy

Answer 1

Drug is applied directly to site of action to exert effect
Common locations are skin, ear, joint/local areas

Question 2

Principles of systemic admin

Answer 2

Drugs are administered externally to be absorbed and have affect at site of action - dermis, subQ etc
Therapeutic concentrations in plasma are important/required

Question 3

Systemic drugs and skin

Answer 3

Site of action is extracellular fluid or interstitial fluid
Protein binding limits movement
Hydrophilic & lipophilic can reach site of action

Question 4

Transdermal drugs

Answer 4

Drugs applied locally at site
Absorbed systemically to have effect at site of action
Help improve patient compliance, decreases dosing freq/cost, good for hard to pill animals

Question 5

Transdermal drug delivery

Answer 5

Improved efficacy for time dependent drugs
Reduced tox with lower peaks (CRI)
Prolonged Tmax
Bypass first pass metabolism
Avoids GI side effects

Question 6

Pros and cons fo transdermal drug delivery

Answer 6

Pros:
Low dose required
Low molecular weight
Moderately lipophilic
Cons:
Hair
Skin thickness variations - site of application

Question 7

Names of transdermal drugs

Answer 7

Mirtazapine
Flunixin
Flea/tick products
Methimazole (compounded)
Fentanyl patch

Question 8

Mirtazapine

Answer 8

Can cause weight loss in acts
Clean ear w dry cloth, wear gloves, DO NOT pet or allow near animals for 2 hours
Alternate ears - to prevent irritation

Question 9

Flunixin

Answer 9

Common in beef cattle
Analgesia
RED - ID treated animals

Question 10

Compounded formulations for transdermal drugs

Answer 10

Maintain healthy skepticism
NOT appropriate for treating systemic infection
Research backed

Question 11

Topical antimicrobials

Answer 11

Good for superficial or generalized conditions
Require frequent admin - ^^ contact time
Can delay healing

Question 12

Types of high concentration topical Antimicrobials

Answer 12

High concentrations @site directly
C/S can underestimate activity
Includes shampoos, ointment, otic preparations

Question 13

Common formulations for topical antimicrobials

Answer 13

Chlorhexidine
Benzoyl peroxide
Nitrofurans
Mupirocin
Silver sulfadiazine
Otic
- antibiotic + antifungal + anti inflammatory
- otitis externa

Question 14

Chlorhexidine

Answer 14

Broad spectrum - good against bacteria, fungi, Protozoa
Cell wall destabilizer = cidal
Ointment, intrauterine suspension, bolus (LA)
Shampoos, sprays, wipes

Question 15

Benzoyl peroxide

Answer 15

Broad spectrum - bacteria, fungi
Reduces skin oil/open pores
- anti inflammatory & degreaser
Release free oxygen radical - bacterial CIDAL
Reduces follicular HK
Comes in shampoos

Question 16

Nitrofurans

Answer 16

Block oxidative reactions in formations of bacteria acetyl coenzyme A
CIDAL @ high concentrations
- topical
-systemic - UTI

Question 17

Spectrum of action of Nitrofurans

Answer 17

UTI
Gram positive & negative - staph, E. Coli

Question 18

Tox of Nitrofurans

Answer 18

Hypersensitivity in people
Possible mutagen and carcinogen in people
PROHIBITED in Food animals - both systemic & topical

Question 19

Mupirocin

Answer 19

Protein synthesis inhibitors
Prevents incorporation of isoleucine into proteins
^ unique mechanisms of other antibacterials

Question 20

Active spectrum of mupirocin

Answer 20

Active against aerobic Gram-positive organisms, some Gram negative
ANTI staph (MRSA, MRSP) action
FDA approved for topical use in dogs

Question 21

Silver sulfadiazine

Answer 21

Silver component interferes with cell wall
- antifungal properties
Sulfadiazine - folic acid pathway
Used to treat burns in humans

Question 22

Enrofloxacin + silver sulfadiazine

Answer 22

Synergistic combo therapy
- gram positive
- gram negative
- fungus
FDA approved for dogs - baytril otic

Question 23

Topical Antimicrobials against otic

Answer 23

Enrofloxacin + silver sulfadiazine
Gentamicin + mometasone + clotrimazole
Florfenicol + Terbinafine + mometasone
Amphenicol
Orbifloxicin + mometasone + posaconazole

Question 24

Gentamicin + mometasone + clotrimazole

Answer 24

Aminoglycosides - gram neg aerobes, staph
Steroids
Azole antifungal - action against malassezia
Increases risk for ototoxicity - esp if ear drums ruptured

Question 25

Florfenicol + Terbinafine + mometasone

Answer 25

Amphenicol - similar to chloramphenicol but no aplastic anemia
Broad spectrum action - staph but not pseudomonas
Allylamine antifungal
Steroid

Question 26

Orbifloxicin + mometasone + posaconasole

Question 27

Systemic antimicrobials

Answer 27

Good for deep conditions
Widespread conditions - deep pyoderma, otitis externa
Can use w combo therapy

Question 28

Drugs of systemic antimicrobials

Answer 28

Beta lactams
- cephalexin, cefadroxil
- amoxicillin - clavulanate
Lincosamides
Potentiated sulfonamides

Question 29

Beta lactam antibiotics

Answer 29

Cephalexin, ceradroxil
- first generation cephalosporins
Amoxicillian-clavulanate: beta lactam/lactamase inhibitor

Question 30

Lincosamides

Answer 30

Clindamycin

Question 31

Potentiated sulfonamides

Answer 31

Tirmethoprim-sulfa
Concerns over toxicity

Question 32

Using systemic antimicrobials

Answer 32

1st or 2nd tier treatment
Case-by-case basis
3rd gen cephalosporins - cefpodoxime
2nd/3rd tier - culture based

Question 33

Fungal therapies

Answer 33

Combo of topical and systemic
Fungus commonly accumulates in hair /skin
- griseofulvin - ring worm
- Terbinafine
- itraconazole

Question 34

Terbinafine

Answer 34

Admin 30-40mg/kg PO q24 for 14 days
Results will be detectable in hair for additional 8 weeks

Question 35

Itraconazole

Answer 35

Concentrations settle in the sebaceous glands, 5-10x plasma concentrations
Detected in surface skin 3-4 weeks after XX therapy

Question 36

Unique PK of systemic antimicrobials

Question 37

Drugs class - imidazole

Answer 37

Drugs:
Miconazole - conofite cream
Clotrimazole - lotrimin topical, mometamax or otomax

Question 38

Drug class- polyene

Answer 38

Drugs:
Nystatin: mycostatin

Question 39

Drug class - allylamine

Answer 39

Drugs :
Terbinafine - osurina & Claro (et al)