Minidoz Mechanism of Action

Pharmacology: Pharmacodynamics: Minidoz is used to prevent pregnancy. The contraceptive effect is based on the interaction of various factors. The most important of these factors are the inhibition of ovulation and changes in the endometrium. Oral contraceptives have been shown to be effective in reducing inflammatory and non-inflammatory lesions in women with acne who require contraception, probably by a multifactorial action on circulating androgens.
Pharmacokinetics: Gestodene is well absorbed with a high bioavailability when given orally. It is extensively bound to plasma proteins; 75 to 87% to sex hormone binding globulin, and 13 to 24% to albumin. Gestodene is metabolised in the liver, less than 1% of a dose being excreted in the urine unchanged. After multiple doses with ethinylestradiol, gestodene has an elimination half-life of about 20 hours.
Ethinylestradiol is rapidly and well absorbed from the gastrointestinal tract, systemic bioavailability is about 40%. Ethinylestradiol is highly protein bound, but unlike naturally occurring oestrogens, which are mainly bound to sex-hormone binding globulin, it is principally bound to albumin. It is metabolised in the liver, initially by aromatic hydroxylation catalysed by the cytochrome P450 isoenzyme CYP3A4, to form 2-hydroxyethinylestradiol and various conjugated metabolites. These are excreted in urine and faeces. Metabolites undergo enterohepatic recycling.
Toxicology: Pre-clinical Safety Data: Ethinylestradiol and gestodene are not genotoxic. Carcinogenicity studies with ethinylestradiol alone or in combination with various progestogens do not indicate any particular carcinogenic hazard to women when used as indicated for contraception. However it should be noted that sex hormones can advance the growth of certain hormone-dependent tissues and tumours.
Reproductive toxicity studies on fertility, development of the fetus or reproductive ability with ethinylestradiol alone or in combination with progestogens revealed no undesirable effects for humans when used as recommended.