In which of the following forms of oral contraception, pills are taken continuously without interruption:

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: 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.

Correct Answer: A

Rationale: The 19-Norprogestins, compared to progesterone derivatives, have potent antiovulatory activity. This means they are highly effective in inhibiting ovulation, making them useful for contraception purposes. They work by suppressing the body's natural hormone production, thereby preventing egg release from the ovary. This fundamental difference sets them apart from progesterone derivatives, which do not exhibit such strong antiovulatory effects.

Correct Answer: D

Rationale: Clomiphene citrate is a selective estrogen receptor modulator that is commonly used to induce ovulation in women experiencing infertility due to anovulation. It works by blocking estrogen receptors in the hypothalamus, leading to an increase in production of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This results in the development and release of mature eggs from the ovaries, thereby promoting ovulation. Clomiphene citrate is an orally active medication, making it convenient and widely utilized in clinical practice for inducing ovulation.

Correct Answer: B

Rationale: Acting insulins are rapid-acting or short-acting insulins that typically start working within 15 minutes after injection, peak around 1-2 hours, and last for about 6-8 hours. These insulins are commonly used to cover meals and correct high blood sugar levels. Options C, D, and E do not pertain to the duration of acting insulins and are unrelated to the scenario described.