Effect of low dose cyproterone acetate on the response of acne to isotretinoin

Acnecutan in the treatment of severe forms of acne

A new technology of production of oral isotretinoin, LIDOSE®, made it possible to increase its bioavailability by 20%, preserve high efficiency of the drug while reducing the quantity of isotretinoin to be taken orally by 20%, and, therefore, reduce both daily and course dose of the drug. The authors present the results of a study of clinical efficiency of Acnecutan in treatment of patients suffering from medium to severe acne taking into account side effects. They also give data on the administration of Acnecutan, which demonstrates the highest efficiency in treatment of this disease.

Effects of isotretinoin on the metabolism of triglyceride-rich lipoproteins and on the lipid profile in patients with acne

Isotretinoin treatment alters the plasma lipid levels but the mechanisms and the effects on the metabolism of triglyceride-rich lipoproteins such as chylomicrons and very-low-density lipoproteins remain unclear. We investigated the effect of isotretinoin on the plasma kinetics of emulsion models of triglyceride-rich lipoproteins and the lipid profile. Ten patients with acne were treated with 0.8 mg/kg of isotretinoin over 4 weeks for comparison with non-treated acne patients. In both groups the plasma kinetic study of a triglyceride-rich emulsion double-labeled with 14C-cholesterol oleate and 3H-triolein was performed after intravenous injection of the emulsion and radioactive counting in plasma samples collected over 60 min. Patients using isotretinoin showed decreased removal from the plasma of the 3H-triglyceride (median 0.019 min-1 TG) compared with controls (median 0.044 min-1, P=0.007), and the removal of the emulsion 14C-cholesterol oleate also tended to be decreased (treatment: 0.011 min-1; controls: 0.024 min-1, P=0.06). The values of total and LDL cholesterol and triglycerides were increased post-treatment (P<0.03). In conclusion, while increasing the fasting plasma concentration of VLDL and LDL, which are traditional risk factors for atherosclerosis, isotretinoin treatment also slows down the metabolism of triglyceride-rich lipoproteins such as chylomicrons, as tested by the emulsion model, an effect that is also increasingly recognized as atherogenic.

Synergistic antiandrogenic effects of topical combinations of 5 alpha-reductase and androgen receptor inhibitors in the hamster sebaceous glands

The androgenic action of dihydrotestosterone (DHT) is antagonized by agents that compete with testosterone for the 5 alpha-reductase enzyme and by agents that block the binding of DHT to its receptor. The topical synergistic effect of 5 alpha-reductase (5 alpha RI) and androgen receptor inhibitors (ARI) was determined by measurement of the sebaceous gland size (SGS) of the ventral ear skin of the intact, sexually mature male Syrian hamsters. Progesterone (P), a 5 alpha RI, and spironolactone (SL), an ARI, produced a dose responsive decrease in SGS at topical concentrations of 0.01% to 5.0%. At concentrations of 1, 3, and 5%, P and SL combinations produced neither an additive nor synergistic inhibition of SGS. At very low concentrations of up to 0.10%, neither P nor SL alone produced any effect on SGS. When combinations of these two steroids were applied at low concentrations, SGS decreased unilaterally to approximately 50%. This synergy occurred best at a P:SL ratio of 1:2. The lower effective concentrations of P may be explained by its greater percutaneous absorption. Synergy was also demonstrated at low concentrations with other antiandrogens: cyproterone acetate, canrenone, hydroxyflutamide, and N-N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane- 17 beta-carboxamide. The use of anti-androgen combinations at low concentrations is of value because of the decreased risk of systemic side effects while maintaining potent topical efficacy.

Evaluation of the atherogenic risk of isotretinoin-induced and etretinate-induced alterations of lipoprotein cholesterol metabolism

Inverse alterations in plasma levels of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol are recognized side effects of systemic treatment with the synthetic retinoids isotretinoin and etretinate. The mass quotients of total plasma cholesterol and high-density lipoprotein cholesterol as well as low-density lipoprotein cholesterol and high-density lipoprotein cholesterol are well-established predictive risk factors of cardiovascular disease. We evaluated and compared these lipoprotein cholesterol ratios of 80 patients treated systemically with isotretinoin (13-cis-retinoic acid) and 81 patients treated with etretinate (aromatic retinoid). Lipoprotein cholesterol data were derived from 5 lipid studies on isotretinoin, including our own results, and 4 published lipid studies on etretinate. For all isotretinoin and etretinate lipid studies, significant increases in the mean plasma levels of total cholesterol and low-density lipoprotein cholesterol and significant decreases in the mean concentration of high-density lipoprotein cholesterol were demonstrated. In comparison with etretinate, oral isotretinoin gave rise to a nearly twofold percent increase of both lipoprotein cholesterol ratios from pretreatment levels. Furthermore, for isotretinoin, an approximately linear dose-related increase of the ratio of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol could be observed. If sustained over long periods, the mean differential rise of the ratio of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol of 0.92 +/- 0.51 for isotretinoin and 0.56 +/- 0.10 for etretinate indicates an increased risk of cardiovascular disease for both retinoids. Etretinate could be identified as the less harmful retinoid for prolonged oral therapy.

Effects of isotretinoin on serum lipids and lipoproteins, liver and thyroid function

Seven patients with severe rosacea were treated with 1 mg/kg per day isotretinoin for 12 wk. There were significant increases in serum triglyceride (p less than 0.001) and cholesterol (p less than 0.001). Triglyceride associated with very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) increased (p less than 0.01), cholesterol in VLDL and LDL increased (p less than 0.01), and levels of HDL cholesterol decreased (p less than 0.01). There were changes in indices of liver function, with increased levels of gamma-glutamyltransferase (GGT) (p less than 0.01), alkaline phosphatase (ALP) (p less than 0.01) and aspartate aminotransferase (AST) (p less than 0.01), and decreased bilirubin levels (p less than 0.05). Although levels of thyroxine and triiodothyronine were lower after treatment (p less than 0.05), there were no changes in basal levels of thyroid-stimulating hormone (TSH), luteinizing hormone (LH) or follicle-stimulating hormone (FSH), and responses to thyrotrophin releasing hormone (TRH) and luteinizing hormone releasing hormone (LHRH) were unchanged. These changes may partially be explained by induction of hepatic microsomal enzymes by isotretinoin.