The drug of choice for controlling postpartum haemorrhage is:

Correct Answer: A

Rationale: Oxytocin is the drug of choice for controlling postpartum hemorrhage. Oxytocin is a hormone that stimulates uterine contractions, helping to prevent and control excessive bleeding after childbirth. It is given via an intravenous infusion or intramuscular injection to help the uterus contract and reduce bleeding by causing the smooth muscle of the uterus to contract. Oxytocin is preferred due to its effectiveness, safety profile, and established role in managing postpartum hemorrhage. Other medications like Methylergometrine, Dihydroergotamine, and Prostaglandin E2 may also be used in certain situations, but oxytocin is the first-line drug for this purpose.

Correct Answer: B

Rationale: The primary mechanism of action of the combined estrogen-progestin oral contraceptive pill is the suppression of FSH and LH release. Estrogen and progestin in the pill work together to inhibit the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland. By suppressing the release of FSH, the pill can prevent the development of a dominant follicle in the ovary. Without a dominant follicle, ovulation is less likely to occur. Additionally, the suppression of LH prevents the release of the mature egg from the ovary. Ultimately, by preventing ovulation, the combined pill effectively reduces the chances of fertilization and pregnancy.

Correct Answer: C

Rationale: The form of oral contraception in which pills are taken continuously without interruption is known as the minipill. Unlike the combined pill, which contains both estrogen and progesterone, the minipill contains only progestin. It is taken daily without any breaks, making it a suitable option for individuals who prefer not to have a menstrual period or have certain medical conditions that may benefit from continuous hormonal contraception.

Correct Answer: B

Rationale: Mifepristone, also known as RU-486, is a medication that can act as a single-dose postcoital contraceptive. It is an anti-progestational steroid that can disrupt implantation and early pregnancy by blocking the action of progesterone, an essential hormone for maintaining a pregnancy. Mifepristone is commonly used in combination with misoprostol for medical abortion but can also be used in a lower dose as a postcoital contraceptive option when taken within 72 hours of unprotected intercourse. In contrast, medications like Clomiphene citrate, Danazol, and Medroxyprogesterone acetate are not typically used as emergency contraceptives.

Correct Answer: A

Rationale: Mifepristone, also known as RU-486, is a synthetic steroid that acts as a potent antiprogestin, meaning it blocks the activity of the hormone progesterone. Its antiprogestin activity is the basis for its use in medical abortion and as an emergency contraceptive. Additionally, mifepristone has weak androgenic activity, meaning it may have some effects similar to male sex hormones, such as testosterone. This combination of potent antiprogestin and weak androgenic activities is what distinguishes mifepristone's pharmacological profile.