Topical Therapeutics in Derm (complete)

Question 1

What are common types of vehicles for topical medications?

Answer 1

A mixture of powder, liquid, and/or grease

1) Ointments
2) Creams
3) Gels
4) Lotions/Solutions
5) Foams
6) Pastes
7) Shake lotions/suspension

Question 2

What are factors you should consider when selecting an appropriate vehicle?

Answer 2

1) Anatomic location
2) Contact allergy/intimacy
3) Irritancy

Question 3

What is the definition of an FTU? Describe it.

Answer 3

Finger Tip Units = 0.5g

Amount of ointment that’s dispensed from a 5mm diameter nozzle and applied to distal third of index finger

BUT I HAVE TINY FINGERS!

Question 4

Estimate the amount of topical medication necessary to treat different body areas

Answer 4

Face/neck: 2.5FTU

Trunk, front, back: 7 FTU

One arm: 3 FTU

One hand (front/back): 1 FTU

One leg: 6 FTU

One foot: 2 FTU

Question 5

What is the classification system for topical corticosteroids?

Answer 5

7 classes:

• Class 1 = most potent
• Class 7 = weakest

Developed based on vasoconstrictor assays

Question 6

What are prototypical topical corticosteroids?

Answer 6

1) The Gentle Touch: Hydrocortisone 2.5%
2) The Almost All-Purpose Weapon: Triamcinolone 0.1%
3) Hercules: Clobetasol Propionate 0.05%

Question 7

What are common adverse effects associated with topical corticosteroid usage?

Answer 7

• Most potent => greater adverse effects
• Skin atrophy

Extensive/long-term use => Systemic side effects

• Adrenal suppression
• Cushing’s syndrome
• growth retardation in kids

Question 8

What are drug factors that affect absorption?

Answer 8

1) Active drug concentration
2) Molecular size of drug/prodrug
3) Lipophilicity of the drug
4) Composition of the vehicle

Question 9

What are patient factors that affect absorption?

Answer 9

1) Presence of barrier disruption
2) Anatomical location
3) Skin hydration
4) Occlusion

Question 10

Describe an ideal vehicle

Answer 10

Easy to apply/remove

Non-toxic

Question 11

What is the composition of ointments?

Answer 11

Water in oil emulsion

Question 12

What is the composition of creams?

Answer 12

Oil in water emulsion

Question 13

What is the composition of gels?

Answer 13

Semisolid emulsion in alcohol base

Question 14

What is the composition of lotions/solutions?

Answer 14

Powder in water (some oil in water)

Question 15

What is the composition of foams?

Answer 15

Special vehicle!!

Pressurized collections of gaseous bubbles in a matrix of liquid film

Question 16

What type of vehicle is least likely to cause contact allergy?

Answer 16

Ointments!

Question 17

What type of vehicle would you use for the scalp?

Answer 17

Gel
Foam
Spray/solution

Question 18

Describe hydrocortisone 2.5%

Answer 18

The Gentle Touch!!

• Cream/ointment
• Class 7
• Efficacious mild eczema in kids/adults
• Tx of inflammatory dermatoses involving face, intertriginous areas, groin

Question 19

Describe Triamcinolone Acetonide 0.1%

Answer 19

The Almost All-Purpose Weapon

• Class 4
• Effective against most moderate spongiotic dermatoses (eczematic, atopic, and allergic dermatitis and arthropod bite)
• Use on trunk and extremities
• Long term use not recommended for facial, intertriginous, groin

Question 20

Describe clobetasol propionate 0.05%

Answer 20

Hercules!!

• Cream/ointment
• CLASS 1
• Tx for acute eruptions that need rapid tx including contact dermatitis or acute drug eruptions
• Avoid use on face, intertriginous areas, groin
• Long term use requires monitoring for adverse rxns