Endocrine Pharmacology Practice Questions

Q: Which of the following is a selective progesterone receptor modulator?

Ulipristal. ***Ulipristal*** - **Ulipristal acetate** is a **selective progesterone receptor modulator (SPRM)** that acts as a progesterone receptor agonist/antagonist. - It is primarily used for **emergency contraception** and for the pre-operative treatment of **uterine fibroids**. *Onapristone* - **Onapristone** is an **antiprogestin** and a **progesterone receptor antagonist**, not a selective modulator. - It has been primarily investigated for its potential role in **breast cancer** treatment but is not approved for general clinical use. *Nomegestrol* - **Nomegestrol** is a **synthetic progestin** used in hormonal contraception. - It functions as a **progesterone receptor agonist** and does not exhibit selective modulation properties. *Toremifene* - **Toremifene** is a **selective estrogen receptor modulator (SERM)**, not a progesterone receptor modulator. - It is used in the treatment of **estrogen receptor-positive metastatic breast cancer** in postmenopausal women.

Q: Long-term steroid ingestion leads to all of the following except:

Hypoglycemia. ***Hypoglycemia*** - Chronic steroid use primarily leads to **hyperglycemia** due to increased **gluconeogenesis** and **insulin resistance**, not hypoglycemia. - Steroids raise blood glucose levels, potentially inducing or worsening **diabetes mellitus**. *Avascular necrosis of head of femur* - Long-term steroid use is a well-established risk factor for **avascular necrosis**, particularly affecting the **femoral head**. - This occurs due to impaired blood supply to the bone, leading to its death. *Cataract* - **Posterior subcapsular cataracts** are a known ocular complication of prolonged systemic corticosteroid therapy. - The mechanism involves direct effects of steroids on lens metabolism and protein aggregation. *Growth retardation* - In children, chronic corticosteroid therapy can suppress growth, leading to **growth retardation**. - This is due to interference with **growth hormone secretion** and direct effects on bone formation.

Q: Finasteride is classified as a:

5-alpha reductase inhibitor. ### ***5-alpha reductase inhibitor*** - **Finasteride** specifically inhibits the enzyme **5-alpha reductase**, preventing the conversion of **testosterone** to **dihydrotestosterone (DHT)** [2], [4]. - This reduction in DHT is clinically useful for treating conditions like **benign prostatic hyperplasia (BPH)** and **androgenetic alopecia** [4]. ### *Phosphodiesterase inhibitor* - **Phosphodiesterase inhibitors** (e.g., sildenafil) typically work by increasing levels of **cyclic GMP**, leading to **vasodilation** and are used for **erectile dysfunction** [3]. - Their mechanism of action is distinct from finasteride's effect on **hormone metabolism**. ### *Alpha-1 blocker* - **Alpha-1 blockers** (e.g., tamsulosin) primarily relax **smooth muscle** in the prostate and bladder neck, improving **urine flow** in BPH [3], [5]. - They act on **adrenergic receptors** and do not affect **hormone synthesis** or **metabolism** [3]. ### *Androgen receptor antagonist* - **Androgen receptor antagonists** (e.g., flutamide) directly block the binding of **androgens** (like testosterone and DHT) to their receptors [1], [4]. - While they also affect androgen action, their mechanism is different from finasteride's **enzyme inhibition** [4].

Q: Which of the following is a synthetic estrogen?

Diethylstilbestrol. ***Diethylstilbestrol*** - **Diethylstilbestrol (DES)** is a **synthetic non-steroidal estrogen** that was historically used as a medication, particularly to prevent miscarriage. - Its use was discontinued after being linked to various adverse effects, including **vaginal clear cell adenocarcinoma** in female offspring whose mothers took DES during pregnancy. *Estrone* - **Estrone** is one of the three major **naturally occurring endogenous estrogens** in humans. - It is the primary estrogen during **menopause** and is derived from androstenedione. *Estriol* - **Estriol** is another of the three major **naturally occurring estrogens**, predominantly produced during **pregnancy** by the placenta. - It is often used as a marker for fetal well-being. *Estradiol* - **Estradiol** is the **most potent and abundant naturally occurring estrogen** in women during their reproductive years. - It plays a crucial role in the development and maintenance of female reproductive tissues and secondary sexual characteristics.

Q: Which of the following has the least glucocorticoid activity?

Cortisone. ***Cortisone*** - **Cortisone has the LEAST glucocorticoid activity** among the options listed. - It is a **prodrug** that must be converted to **hydrocortisone (cortisol)** by 11β-hydroxysteroid dehydrogenase in the liver to become active. - Its glucocorticoid potency is approximately **0.8** relative to hydrocortisone (when hydrocortisone = 1). - Due to variable hepatic conversion, it has **lower and less predictable glucocorticoid effects** compared to other agents. *Fludrocortisone* - Primarily used for its **potent mineralocorticoid activity** (125× that of hydrocortisone). - However, it retains **significant glucocorticoid activity** approximately **10-15 times** that of hydrocortisone. - Despite being marketed as a mineralocorticoid, its glucocorticoid potency is **considerably higher than cortisone**. *Dexamethasone* - **Highly potent synthetic glucocorticoid** with negligible mineralocorticoid activity. - Glucocorticoid potency is approximately **25-30 times** that of hydrocortisone. - Long duration of action (36-72 hours) and excellent CNS penetration. *Betamethasone* - **Highly potent synthetic glucocorticoid**, structurally similar to dexamethasone (differs only in stereochemistry at C-16). - Glucocorticoid potency is approximately **25-30 times** that of hydrocortisone. - Minimal mineralocorticoid activity, with similar clinical applications to dexamethasone.

Q: Which of the following drugs acts directly to induce an erection without the need for sexual stimulation?

Alprostadil. ***Alprostadil***- **Alprostadil** is a **prostaglandin E1** analog that can directly induce vasodilation in the penile arteries, leading to an erection without sexual stimulation [1].- It is typically administered via **intracavernosal injection** or as a **urethral suppository**.*Sildenafil*- **Sildenafil** is a **PDE5 inhibitor** that works by enhancing the effects of **nitric oxide**, which is released in response to sexual stimulation [2, 3].- It requires **sexual arousal** to be effective, as it doesn't directly initiate the erectile process [2, 3].*Tadalafil*- Similar to sildenafil, **tadalafil** is also a **PDE5 inhibitor** that works by increasing cGMP levels and promoting smooth muscle relaxation [2, 3].- Its action is dependent on the release of **nitric oxide** triggered by sexual stimulation [2, 3].*Testosterone*- **Testosterone** is a hormone involved in sex drive and overall erectile function over time, but it does not directly or acutely induce an erection.- Its primary role in erectile dysfunction is in cases of **hypogonadism**, and it requires sexual stimulation for its effects on erection.

Q: Which of the following is an intermediate-acting insulin?

NPH insulin. ***NPH insulin*** - **NPH (Neutral Protamine Hagedorn) insulin** is characterized by its intermediate duration of action, typically peaking in 4-12 hours and lasting up to 24 hours [1]. - This intermediate profile is achieved by combining insulin with **protamine**, which slows its absorption from the subcutaneous injection site [1]. *Insulin lispro* - **Insulin lispro** is a **rapid-acting insulin** analog, designed to act very quickly after injection, typically within 15-30 minutes [1, 2]. - Its quick onset and short duration make it suitable for dosing **immediately before meals** to control post-prandial glucose levels [1]. *Regular insulin* - **Regular insulin** is a **short-acting insulin**, with an onset of action around 30-60 minutes and a peak effect typically within 2-4 hours. - It is often administered **30 minutes before meals** and can also be used intravenously in acute situations like diabetic ketoacidosis. *Insulin glargine* - **Insulin glargine** is a **long-acting insulin** analog, providing a prolonged and relatively peakless effect over 24 hours [1, 2]. - Its primary role is to provide **basal insulin coverage**, mimicking the body's continuous background insulin production [1, 2].

Q: Which steroid has the maximum mineralocorticoid activity?

Fludrocortisone. ***Fludrocortisone*** - **Fludrocortisone** is a synthetic corticosteroid specifically designed to have potent **mineralocorticoid activity**, with significant sodium-retaining properties. - Its high affinity for **mineralocorticoid receptors** distinguishes it from other steroids and makes it effective in treating conditions like **Addison's disease** and **postural orthostatic tachycardia syndrome (POTS)** due to its ability to retain sodium and water. *DOCA (Deoxycorticosterone acetate)* - While **DOCA** does possess significant **mineralocorticoid activity** and was historically used for this purpose, **fludrocortisone** is generally considered to have a stronger and more sustained effect in clinical practice. - **DOCA's** mineralocorticoid potency is substantial but slightly less than that of **fludrocortisone** when compared on a weight basis for equivalent sodium retention. *Prednisolone* - **Prednisolone** is primarily a **glucocorticoid** with potent anti-inflammatory and immunosuppressive effects. - It has minimal to negligible **mineralocorticoid activity** and is not used for salt retention purposes. *Triamcinolone* - **Triamcinolone** is a potent **glucocorticoid** with a long duration of action and is known for its strong anti-inflammatory properties. - It has virtually no **mineralocorticoid activity**, making it unsuitable for conditions requiring sodium retention.

Q: Which of the following compounds has been studied as a potential male contraceptive?

Gossypol. ***Gossypol*** - **Gossypol** is a natural compound derived from cotton plants that has been extensively studied for its **male contraceptive** properties due to its effect on sperm production. - Research has shown that gossypol inhibits **spermatogenesis** by affecting various enzymes and processes within the testes, leading to reduced sperm count and motility. However, its use has been limited due to concerns about potential side effects, including **hypokalemia** and irreversible infertility in some individuals. *Quinesterol* - **Quinesterol** is a **synthetic estrogen** primarily used as a component of oral contraceptives for women. - Its mechanism of action involves suppressing ovulation and altering the endometrial lining, making it unsuitable as a male contraceptive. *Saheli* - **Saheli**, also known as Centchroman or Ormeloxifene, is a **non-steroidal oral contraceptive** developed in India and is used for women. - It acts as a **selective estrogen receptor modulator (SERM)** in the uterus, preventing implantation, and is not designed or effective for male contraception. *MALA-N* - **MALA-N** (Norethisterone enanthate or NET-EN) is a **long-acting injectable progestogen contraceptive** used for women in India. - It works by suppressing ovulation, thickening cervical mucus, and altering the endometrium, making it unsuitable for male contraception.

Q: Which tocolytic drug is most characteristically associated with pulmonary edema as an adverse effect?

Ritodrine. ***Ritodrine*** * **Ritodrine** is a **beta-2 adrenergic agonist** that relaxes the uterus, but its non-selective nature can lead to adverse effects like **pulmonary edema** due to fluid retention and myocardial depression. * Other side effects include maternal tachycardia, palpitations, tremors, and hyperglycemia due to its systemic adrenergic activation. *Indomethacin (NSAID)* * **Indomethacin** is a **prostaglandin synthetase inhibitor** that can cause premature closure of the **ductus arteriosus** in the fetus if used for prolonged periods or late in gestation. * Maternal side effects typically include gastrointestinal upset, nausea, and heartburn, with pulmonary edema being extremely rare. *Atosiban (oxytocin receptor antagonist)* * **Atosiban** blocks oxytocin's action, a physiological mechanism for inhibiting uterine contractions, and is considered to have a generally favorable safety profile. * Common side effects are nausea, headache, and dizziness, and it is not associated with pulmonary edema. *Magnesium Sulfate* * **Magnesium sulfate** is a central nervous system depressant and calcium antagonist that can cause **respiratory depression** and **hypotension** in the mother, and rarely maternal pulmonary edema, especially with renal impairment or rapid infusion. * While it can cause pulmonary edema, it is less common than with beta-agonists like ritodrine and usually associated with specific risk factors or overdose.

Question 1

Which of the following is a selective progesterone receptor modulator?

Accepted Answer

Ulipristal

Answer

Onapristone

Answer

Nomegestrol

Answer

Toremifene

Question 2

Long-term steroid ingestion leads to all of the following except:

Accepted Answer

Hypoglycemia

Answer

Avascular necrosis of head of femur

Answer

Growth retardation

Answer

Cataract

Question 3

Finasteride is classified as a:

Accepted Answer

5-alpha reductase inhibitor

Answer

Phosphodiesterase inhibitor

Answer

Alpha-1 blocker

Answer

Androgen receptor antagonist

Question 4

Which of the following is a synthetic estrogen?

Accepted Answer

Diethylstilbestrol

Answer

Estrone

Answer

Estriol

Answer

Estradiol

Question 5

Which of the following has the least glucocorticoid activity?

Accepted Answer

Cortisone

Answer

Fludrocortisone

Answer

Dexamethasone

Answer

Betamethasone

Question 6

Which of the following drugs acts directly to induce an erection without the need for sexual stimulation?

Accepted Answer

Alprostadil

Answer

Sildenafil

Answer

Tadalafil

Answer

Testosterone

Question 7

Which of the following is an intermediate-acting insulin?

Accepted Answer

NPH insulin

Answer

Insulin lispro

Answer

Insulin glargine

Answer

Regular insulin

Question 8

Which steroid has the maximum mineralocorticoid activity?

Accepted Answer

Fludrocortisone

Answer

DOCA

Answer

Prednisolone

Answer

Triamcinolone

Question 9

Which of the following compounds has been studied as a potential male contraceptive?

Accepted Answer

Gossypol

Answer

Quinesterol

Answer

Saheli

Answer

MALA - N

Question 10

Which tocolytic drug is most characteristically associated with pulmonary edema as an adverse effect?

Accepted Answer

Ritodrine

Answer

Indomethacin

Answer

Atosiban

Answer

Magnesium Sulfate

Endocrine Pharmacology — MCQs

Endocrine Pharmacology — MCQs

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