Retinoids

Question 1

Acitretin

Answer 1

Synthetic retinoid - 2nd gen
10–50 mg/day, depending upon disorder
-Erythrodermic and Pustular PsO, Acne, Good maintenance therapy PsO
Metabolite of etretinate; half-life 2 days
o avoid pregnancy for at least 3 years after d/c
o Side effects: teratogenicity, hyperlipidemia, alopecia, arthralgias, abnormal LFTs, reduced night
vision, bone and joint pain, pseudotumor cerebri, xerosis of mucous membranes
-Check CBC, CMP, Lipids, Preg test, Blood sugar, regular bone screens, optho

Question 2

Isotretinoin

Answer 2

Acne
0.5–2 mg/kg/day (16-20 wks) , reaching a cumulative dose of 120–150 mg/kg (goall 200 mg/kg reduced relapse rates)
increased absorption with fatty meal;
half-life 18-20 hours;
o Results in atrophy of sebaceous glands, reduction in sebum (up to 90% by week 1) so P. acnes unable to thrive, normalization of follicular keratinization
oavoid pregnancy for at least 1 month after d/c
o Side effects: cheilitis, xerosis, alopecia, skin fragility, eczematous dermatitis, photophobia, keratitis, myalgias, headache, pseudotumor cerebri (with concomitant TCN use), skeletal hyperostosis, teratogenicity, elevated triglycerides (25-45%, most common lab abnormality), elevated LFTs, reduced night vision, pyogenic granulomas, staph colonization
o Retinoid teratogenicity: craniofacial, cardiac, thymic and CNS malformations
- 2 forms of birth control in females child bearing age
-Baseline labs: lipid panel, LFT, preg test(2 neg tests 30 days apart before starting), recheck 2 months after starting

Question 3

Retinoids

Answer 3

What: Vitamin A analog
MOA: Normalizes keratinization (↓ follicular occlusion): inhibits collagenase, downregulates proliferative keratins (K6 and K16), increases filaggrin production/keratin filaments, antagonizes IL-6, downregulates TLR2

Question 4

Generation of Retinoid

Answer 4

1st (Tretinoin, Isotretinoin)
2nd (etretinate, acitretin)
3rd gen(tazarotene, Adapalene, Bexarotene)