Chapter 24 — Quiz

DataField.Dev

Chapter 24 — Quiz

Twenty-two items. Answer without looking at the chapter; the answer key follows.

1. The research program that eventually produced bremelanotide was originally aimed at:

A. treating erectile dysfunction
B. producing skin tanning without ultraviolet exposure
C. suppressing appetite in genetic obesity
D. triggering ovulation in assisted reproduction

2. Alpha-melanocyte-stimulating hormone (α-MSH) is cleaved from a precursor protein that also gives rise to:

A. insulin and glucagon
B. GnRH and kisspeptin
C. ACTH and β-endorphin
D. oxytocin and vasopressin

3. Which melanocortin receptor sits on melanocytes and governs pigmentation?

A. MC1R
B. MC2R
C. MC4R
D. MC5R

4. Bremelanotide is best described structurally as:

A. a linear 15-residue peptide
B. a cyclic 7-amino-acid peptide
C. a 30-residue analog of a gut hormone
D. a monoclonal antibody fragment

5. Setmelanotide, an MC4R agonist approved for certain rare genetic obesity syndromes, causes skin hyperpigmentation. The best explanation is:

A. an unexplained idiosyncratic reaction
B. contamination of the product
C. residual activity at MC1R, which sits on melanocytes
D. a downstream consequence of weight loss

6. PDE5 inhibitors such as sildenafil act:

A. centrally, on hypothalamic desire circuits
B. peripherally, on genital vascular smooth muscle
C. on the pituitary, to alter LH release
D. on melanocortin receptors in the spinal cord

7. Bremelanotide acts:

A. peripherally, on blood flow
B. centrally, on circuits associated with sexual motivation
C. on the adrenal cortex
D. locally, at the site of injection only

8. A person with normal genital vascular response and no sexual interest whatsoever is most accurately described as having:

A. a desire problem, not a blood-flow problem
B. a blood-flow problem
C. both, by definition
D. no medical problem, since the physiology is intact

9. Bremelanotide's approved indication covers:

A. sexual dysfunction in adults of any sex
B. hypoactive sexual desire disorder in premenopausal women
C. hypoactive sexual desire disorder in postmenopausal women
D. erectile dysfunction unresponsive to PDE5 inhibitors

10. The pivotal bremelanotide trials measured their co-primary endpoints using:

A. serum hormone concentrations
B. partner-reported satisfaction
C. validated desire and desire-related distress instruments
D. genital blood flow measurement

11. In those trials, the number of satisfying sexual events:

A. increased substantially versus placebo
B. did not separate from placebo
C. was not examined
D. decreased versus placebo

12. The most common adverse effect reported in the bremelanotide trials was:

A. headache
B. nausea
C. hypotension
D. injection-site infection

13. Why is that adverse effect a particularly meaningful practical limitation for this drug?

A. because it is life-threatening
B. because the drug is taken as needed, in anticipation of sexual activity
C. because it prevents the drug from being absorbed
D. because it worsens with continued use in all patients

14. The distress criterion in the HSDD diagnosis means that:

A. any person with low desire meets criteria
B. low desire that does not trouble the person is not a disorder
C. the diagnosis requires a partner's report
D. distress alone is sufficient for the diagnosis

15. The chapter's ✅ rating for bremelanotide in premenopausal women with HSDD asserts that:

A. the drug produces a large, obvious effect
B. the evidence supports the claim in that population
C. the drug is superior to all alternatives
D. no significant adverse effects occur

16. Afamelanotide (melanotan I) is approved for:

A. cosmetic tanning
B. hypoactive sexual desire disorder
C. increasing pain-free light exposure in erythropoietic protoporphyria
D. rare genetic obesity syndromes

17. In erythropoietic protoporphyria, pain on light exposure is caused by:

A. an autoimmune reaction to ultraviolet-damaged keratinocytes
B. accumulated protoporphyrin IX absorbing visible light and generating reactive species
C. absence of melanocytes in the skin
D. hypersensitivity of peripheral nerve endings to heat

18. Melanotan II's regulatory status is best stated as:

A. approved in Europe but not the United States
B. approved for restricted specialist use
C. not approved as a medicine in any major jurisdiction
D. approved for cosmetic use only

19. The published case reports on melanotan II establish:

A. a quantified increase in melanoma risk
B. a signal warranting concern, but not a quantified risk
C. that the compound is safe at low exposure
D. nothing at all, since case reports carry no evidentiary weight

20. The chapter describes the melanotan II ❌ as unusual because:

A. it is based on a failed randomized trial
B. it is reinforced by a safety signal rather than resting only on absent efficacy evidence
C. it was assigned on the basis of the compound's cosmetic purpose
D. it applies to the molecule rather than to a claim

21. Kisspeptin's position in the reproductive axis is:

A. downstream of the gonads, mediating feedback only
B. upstream of GnRH, essential for activation of the axis
C. within the pituitary, releasing LH directly
D. a peripheral hormone acting on the testis and ovary

22. Kisspeptin for reproductive or sexual indications is rated 🔬 primarily because:

A. the underlying physiology is doubtful
B. animal data contradict the human data
C. the physiology is established but clinical work is early-phase, with no approved indication
D. the peptide cannot be administered to humans

Answer key

**1 — B.** The program sought tanning without ultraviolet exposure; effects on sexual arousal were an unexpected observation during that work, and a separate development program followed. (§24.1) **2 — C.** Proopiomelanocortin yields α-MSH, ACTH, and β-endorphin depending on where and how it is processed — one precursor, several unrelated hormones. (§24.1) **3 — A.** MC1R on melanocytes governs pigmentation. MC2R responds to ACTH in the adrenal cortex; MC3R and MC4R are central; MC5R is largely exocrine. (§24.2) **4 — B.** A cyclic heptapeptide of roughly 1,025 Da, closed by a lactam bridge, containing a D-phenylalanine and a non-standard residue. (§24.1) **5 — C.** The receptor map predicts it. A peptide-like melanocortin agonist with MC4R activity generally carries some MC1R activity, and MC1R is the pigmentation receptor. Whether "side effect" is the right word is a fair discussion — it is a direct on-target consequence at a different receptor subtype. (§24.2) **6 — B.** PDE5 inhibitors act peripherally, preventing the breakdown of cyclic GMP in genital vascular smooth muscle, which sustains a response that arousal has already initiated. (§24.3) **7 — B.** Centrally, at melanocortin receptors in hypothalamic circuits associated with sexual motivation. (§24.3) **8 — A.** Desire and arousal are partly independent components. Intact vascular physiology with absent interest is a desire complaint, and D is wrong — the presence of intact physiology says nothing about whether the person is distressed. (§24.3) **9 — B.** Premenopausal women with acquired, generalized HSDD. Postmenopausal women and men are not covered. (§24.4) **10 — C.** Co-primary endpoints were a validated desire domain score and a validated measure of desire-related distress. (§24.4) **11 — B.** The endpoint was examined and did not separate from placebo. This is one of the honest limitations the chapter insists on stating. (§24.4) **12 — B.** Nausea, reported by a large minority of participants — on the order of four in ten — most often with first exposure. (§24.4) **13 — B.** For an as-needed drug taken in anticipation of a specific event, each administration is a fresh decision, the adverse effect lands in exactly the window the drug was taken to improve, and there is no adaptation curve to wait out. (§24.4) **14 — B.** The distress criterion is what separates a disorder from ordinary variation. It is routinely dropped in popular coverage, and dropping it is what makes the diagnosis look like an attempt to pathologize the low end of a normal distribution. (§24.4) **15 — B.** ✅ is a statement about evidential support for a claim in a population, not about effect magnitude. Bremelanotide is the book's clearest example of a claim that scores high on the first axis and low on the second. (§24.4) **16 — C.** Increasing pain-free light exposure in adults with erythropoietic protoporphyria — a narrow, approved, randomized-trial-supported indication. (§24.5) **17 — B.** Reduced ferrochelatase activity leads to protoporphyrin IX accumulation; the molecule absorbs visible light and generates reactive species in the surrounding tissue. This is why ultraviolet-targeted sunscreen helps little. (§24.5) **18 — C.** Not approved as a medicine in any major jurisdiction, while being widely sold and used for cosmetic tanning. (§24.6) **19 — B.** They establish a signal warranting concern; they do not establish a quantified risk. D is the overcorrection the chapter specifically warns against — case reports are near-useless for efficacy and genuinely valuable for rare, distinctive harms. (§24.6, Chapter 5 §5.2) **20 — B.** A standard ❌ is a statement about absence of supporting evidence. This one is additionally reinforced by published harm reports, which changes the practical posture from "wait for data" to "there is a specific documented concern that would need to be affirmatively resolved." It does not violate rule 2: ❌ still describes the evidence, and here the evidence includes harm reports. (§24.6) **21 — B.** Kisspeptin neurons act upstream of GnRH neurons and are central to generating the pulsatile signal the axis requires. Loss-of-function mutations in the receptor cause failure of puberty. (§24.7) **22 — C.** The physiology is established and essential, but the clinical work is early-phase and small, with mechanistic and imaging endpoints rather than outcomes, and there is no approved indication. Rule 3 — never upgrade with mechanism — is what keeps excellent physiology from producing an inflated rating. (§24.7)