Oral isotretinoin in different dose regimens for acne vulgaris: A randomized comparative trial

Abstract

We conclude that for severe acne either conventional high doses of isotretinoin may be used or we can give conventional high dose for initial eight weeks and later maintain on low doses. Use of isotretinoin should be considered in mild to moderate acne also, in low doses; 20 mg, alternate day seems to be an effective and safe treatment option in such cases.

Blue light therapy versus low dose isotretinon in mild to moderate acne

“…To decrease the incidence of side-effects and to make the therapy protocol simpler, the lower dose regimen has been tried by various authors. Most of these studies have found that low-dose and intermittent regimens of isotretinoin are effective in moderate to severe acne with a low incidence and severity of side-effects [12].…”

Bioequivalence Study of Two Formulations That Contain Isotretinoin 20 mg Capsules in Healthy Colombian Volunteers

“…After the 40 mg oral administration of Isotretinoin to fasting healthy volunteers, the maximum plasma concentrations reported ranged from 167-459 ng/ mL, reached in 3.2 h [2]; same dose in acne patients caused maximum plasma concentrations ranging from 98-535 ng/mL (average 262 ng/ mL) in 2-9 h average [3]. Isotretinoin bioavailability increases from 1½ to 2 times more, when ingested with food.…”

“…One of the main metabolites, 4-oxo-isotritenoine, is present in maximum plasma concentrations after 6 h of a single dose, remaining constant after 7 days Isotretionion's elimination half-life is 7-37 h. The medicine binds to plasma proteins, almost exclusively to albumin (99.9%). Another characteristic of this drug is that it crosses the placental barrier [2,3]. The elimination halflife on healthy subjects after a 40 mg dose ranges from 10-20 h, being up to 90 h on patients who reach stationary states.…”

“…Epidermic concentration is very low, and has not been found a progressive accumulation in serum, epidermic or subcutaneous cell tissue. Once treatment is discontinued, Isotretinoin disappears from serum and skin in 2-4 weeks [2,3]. According to FDA and EMA, two products that contain the same active principle are bioequivalent if they meet the conditions above [4,5].…”

A randomized, open-label, comparative study of efficacy of low-dose continuous versus low-dose intermittent oral isotretinoin therapy in moderate-to-severe acne vulgaris

“…[5] Hence, considerable doubt exists in deciding which protocol would give the maximum benefits, so this study has been undertaken to determine and compare the efficacy of the oral isotretinoin in low-dose continuous with low-dose intermittent in the treatment of moderate-to-severe acne vulgaris. Sample size calculation: [6] Sample size (n) = Z 2 P (1-P)/d 2 = 1.96 2 × 96.03 (1-96.03)/ (19.18) 2 = ~95 (Z is 1.96 for 95% confidence interval, P = maximum response score, and d = the difference between maximum and minimum score).…”