Introduction :
Puregest contains progesterone identical to that secreted by human ovary. Puregest is for vaginal/ rectal/oral administration.

Composition :
Each soft gelatin capsule contains progesterone 100mg, 200mg or 400mg.

Clinical Pharmacology :
Mechanism of Action
Progesteron is lypophilic in nature and diffuse freely into cells, where they bind to the progesterone receptors and exert their progestational activity. The steroid-receptor complex binds to DNA in the nucleus, thereby inducing the synthesis of specific proteins. Progesterone receptor concentrations are low in absence of estrogens, and increase following estrogen administration.

Pharmacokinetics :
Absorption :
Vaginal route :
It is well absorbed when administered bucally, rectally or vaginally. Rectal or vaginal administration of 100-400mg produces concentrations in the luteal range, which are maximal within 1-8h and then decline over 24h.

Oral route :
The micronised progesterone is absorbed through digestive tract. The rise in progesterone starts from the first hour and the highest plasma levels are observed 1 to 3 hours after intake.

Distribution :
Progesterone has a distribution phase half-life of between 3-6 minutes, followed by an elimination phase half-life of 19-95 minutes. The apparent volume of distribution is 17-29 liter. Progesterone is taken up by fat, from which it is slowly released. Circulating progesterone is extensively bound to plasma proteins, especially albumin and corticosteroid-binding globulin. Only small amounts are associated with erythrocytes or platelets. Concentrations in cerebrospinal fluid are about 10% of those in plasma.
Inca specialities.

Metabolism :
Progesterone is metabolised, mainly in the liver, by reduction of the A-ring, hydroxylation and conjugation. The principal metabolite is pregnanediol, other metabolites, notably 20-dihy droprogesterone, which is present in small concentrations in plasma, and 5-pregnane-3, 20-dione, have weak progestational activity.

Excretion :
Progesterone undergoes extensive biotransformation, mainly in the liver (approximately 66%) And in tissues such as kidneys, brains, uterus and skin. The metabolites of progesterone are conjugated in the liver with glucuronic acid and excreted primarily in the urine; between 19 and 40% of a dose of labeled.
Progesterone appears in the urine within 24h. A smaller quantity (8-17%) is excreted in the feces and there is extensive enterohepatic circulation of metabolites. Metabolites of progesterone are mainly excreted in the urine as glucuronide conjugates.

Drug Interactions :
No potentially hazardous interactions have been reported.

Side Effects :
The menstrul cycle may be shortened or there may be inter-menstural bleeding.
Menstruation may occur earlier than expected , or , more rarely, menstruation may be delayed.

Oral Route :
Drowsiness or giddiness arising 1 to 3 hours after ingestion of the product.

Vaginal/Rectal route :
Soreness, diarrhoea and flatulence may occur with rectal administration. As with other vaginal and rectal. Preparations, some leakage of the capsule base may occur.

Overdosage :
There is wide margin of safety with progesterone, but overdosage may produce euphoria or dysmenorrhoea.

Dosage and Administration

VAGINAL/RECTAL ADMINISTRATION :
Each capsule should be deeply inserted into the vagina.

Supplementation of the luteal phase in case of sterility due to luteal deficiency. The dosage recommended is 400 to 600 mg per day starting with the day of injection of hCG up to the 12 week of pregnancy.

To help pregnancy and for treatment of threatened abortion. The dosage recommended is 200 to 400 mg per day in divided doses. For pre-menstrual syndrome commence treatment on day 14 of menstrual cycle and continue treatment until onset of menstruation. If symptoms are present at ovulation commence treatment on day 12.

Presentation :
Puregest 100mg, 200mg, and 400mg is available in blister pack of 10 capsules.