Dermatological Pharmacology 1 Flashcards
A 23-year-old woman suffering with a dermatological condition is prescribed a topical drug. Which of the following would contribute to the greatest amount of the drug being successfully delivered to its molecular targets present within the skin?
A) Occlusion
B) Metabolism of the drug in the epidermis
C) Drug application to intact stratum corneum
D) Drug application to body areas with a thick stratum corneum layer
A is correct. Occlusion increases the temperature and hydration of the stratum corneum which increases drug penetration.
(B) Drug metabolism in the skin does not increase drug penetration.
(C) Compared to intact stratum corneum drug penetration is greater in broken/compromised stratum corneum. (D)There is an inverse relationship between the thickness of the stratum corneum and drug penetration.
A 13-year-old boy presents to a dermatologist with numerous comedones, inflammatory papules, and pustules on his face, back, and upper chest. The physician diagnosed him with moderate acne vulgaris and prescribed a gel- based topical agent that is to be applied once a day to affected skin. Which of the following drugs did the physician most likely prescribe? A) Minoxidil B) Permethrin C) Tretinoin D) Cetirizine E) Oxybenzone
C is correct. Topical tretinoin is a retinoid used to treat mild to moderate acne. None of the other drugs listed are used to treat acne.
A 15-year-old girl reports to a dermatologist complaining of uncontrollable facial acne breakouts that have proven unresponsive to over-the-counter acne medications. Physical examination reveals erythema of the face, comedones, papules, pustules, and nodules and cysts that are painful to the touch. The physician orders a urine pregnancy test that displays a negative result. The patient is started on combined oral contraceptive therapy. A month later at the beginning of her next menstrual cycle, the patient returns and once again takes a urine pregnancy test that comes up negative. After telling the patient to remain on combined oral contraceptive therapy and receiving informed consent, the dermatologist prescribes an oral medication to treat her acne. Which of the following drugs is she taking to treat her dermatological condition? A) Tazarotene B) Finasteride C) Diphenhydramine D) Isotretinoin E) Adapalene
D is correct. Isotretinoin is a systemic retinoid (the girl was prescribed an oral drug) used to treat moderate to severe acne. Patients and physicians must register with the iPLEDGE follow-up program to ensure women with child bearing potential do not become pregnant because of the high risk of birth defects. (A) and (E) Tazarotene and adapalene are topical retinoids used to treat acne. None of the other drugs are used to treat acne.
A 49-year-old man complains to his dermatologist of a receding hairline and thinning hair at the crown of his head. His physician prescribes a drug that inhibits the conversion of testosterone to dihydrotestosterone by 5α-reductase. Which of the following drugs was described? A) Adapalene B) Finasteride C) Minoxidil D) Fexofenadine E) Malathion
B is correct. Finasteride is used to treat androgenetic alopecia, and its mechanism of action is the one described. (C) Minoxidil is also used to treat androgenetic alopecia however it is not a 5α-reductase inhibitor. The other drugs listed are not used to treat baldness.
A 22-year-old woman presents to her physician with a complaint of persistent itching in the pubic area. A skin exam shows infestation (Figure 1) and microscopic examination of the hair shaft is shown in (Figure 2). Which of the following drugs is an appropriate treatment? A) Para-aminobenzoic acid B) Minoxidil C) Adapalene D) Avobenzone E) Permethrin
E is correct. The woman is infested with Pthirus pubis (crab/pubic louse). **Students are expected to make the diagnosis from the information given - review ectoparasite clinical presentation and diagnosis in Dr. Reid’s lecture. Permethrin is a pediculicide and scabicide. None of the other agents are used to treat lice infestation.
