A 31-year-old woman with HIV disease complains of vulvar itching, burning, and vaginal discharge with rancid odor for 2 months. She presents to the ambulatory care clinic for evaluation. She has had unprotected sexual intercourse with multiple male partners during the past several weeks. The vaginal discharge is yellow-green in color, frothy, and has a pH of 7.0. Vulvovaginal examination reveals vulvar edema and erythema and petechia on the cervix. Wet smear reveals large numbers of mature epithelial cells, white blood cells, and a fusiform protozoan organism. What is the most appropriate treatment for this patient?

Correct Answer: C

Rationale: The most appropriate treatment for this patient is option C: Metronidazole. The patient's presentation with vulvar itching, burning, vaginal discharge with a rancid odor, yellow-green frothy discharge, a pH of 7.0, vulvar edema, erythema, and petechiae on the cervix, along with the presence of a fusiform protozoan organism on wet smear are indicative of trichomoniasis, a sexually transmitted infection. Metronidazole is the drug of choice for treating trichomoniasis due to its effectiveness against protozoa. Option A, Amoxicillin, is an antibiotic mainly used for bacterial infections and would not be effective against a protozoan infection like trichomoniasis. Option B, Ciprofloxacin, is also an antibiotic primarily used for bacterial infections and is not the appropriate treatment for trichomoniasis. Option D, Ofloxacin, is another antibiotic and not the correct choice for treating trichomoniasis. In an educational context, it is important for healthcare providers to be able to recognize the symptoms and signs of different sexually transmitted infections and to understand the appropriate treatments for each. This case highlights the importance of thorough history-taking, physical examination, and laboratory investigations in diagnosing and managing such infections. It also emphasizes the need for accurate prescribing practices to ensure optimal patient outcomes.

Correct Answer: D

Rationale: In this scenario, the correct answer is D) Phenytoin. Cimetidine is a cytochrome P450 inhibitor, specifically CYP1A2 and CYP2C9. Phenytoin is primarily metabolized by CYP2C9, so the use of cimetidine can lead to increased levels of phenytoin in the body. This interaction can potentially result in phenytoin toxicity, leading to adverse effects. Option A) Dronabinol is primarily metabolized by CYP2C9 and CYP3A4, not significantly affected by cimetidine. Option B) Erythromycin is a substrate of CYP3A4 and is not significantly impacted by cimetidine's inhibition of CYP1A2 and CYP2C9. Option C) Ketoconazole is a strong inhibitor of CYP3A4 but not directly related to the enzymes affected by cimetidine. Educationally, understanding drug interactions is crucial in clinical practice to prevent adverse effects and ensure optimal patient outcomes. Healthcare providers must be aware of potential interactions between medications to make informed decisions when managing patients with multiple comorbidities and complex medication regimens.

Correct Answer: C

Rationale: The correct answer to this question is C) 5-HT3 receptors. Chemotherapy-induced nausea and vomiting (CINV) is a common side effect of many chemotherapeutic agents. 5-HT3 receptors are specifically targeted to alleviate this symptom because they are located both centrally in the chemoreceptor trigger zone and peripherally on vagal afferents in the gastrointestinal tract. By blocking these receptors, the pharmacologic agent can effectively reduce nausea and vomiting in the patient. Option A) 5-HT1 receptors are not primarily involved in the pathophysiology of CINV. These receptors are more associated with vasoconstriction, modulation of neurotransmitter release, and other functions. Option B) 5-HT2 receptors are also not the main target for treating CINV. They are involved in various physiological processes such as smooth muscle contraction and mood regulation. Option D) Dopamine receptors are more closely related to the stimulation of the chemoreceptor trigger zone and are targeted in other types of antiemetic treatments, such as those used for postoperative nausea and vomiting. In an educational context, understanding the mechanisms of action of different pharmacologic agents used in managing chemotherapy side effects is crucial for healthcare professionals involved in oncology care. By grasping the specific receptor targets and pathways involved in CINV, healthcare providers can tailor treatment plans to optimize patient comfort and quality of life during cancer therapy.

Correct Answer: D

Rationale: In this scenario, the correct answer is D) Ketoconazole. Ketoconazole is an antifungal medication known to cause gynecomastia as a side effect due to its antiandrogenic properties. Gynecomastia is the abnormal enlargement of male breast tissue. Ketoconazole inhibits the synthesis of testosterone, leading to hormonal imbalances that can result in this side effect. Regarding the other options: A) Amphotericin B is an antifungal medication commonly used for systemic fungal infections. It is not associated with causing gynecomastia. B) Caspofungin is a different class of antifungal medication known as an echinocandin. It does not typically cause gynecomastia. C) Flucytosine is an antifungal agent used in combination therapy. It does not have a known association with gynecomastia. Educationally, understanding the side effects of medications is crucial for healthcare professionals to make informed decisions when prescribing and managing patient care. Recognizing the potential side effects of medications can help prevent and manage adverse reactions, ensuring patient safety and well-being.

Correct Answer: D

Rationale: In this scenario, the correct medication to stimulate bone marrow production of platelets for the 68-year-old man with prostate cancer undergoing chemotherapy is option D) Oprelvekin. Oprelvekin is a thrombopoietic growth factor that stimulates the production of platelets from the bone marrow. Option A) Aldesleukin is a cytokine used to treat certain types of cancer but does not specifically target platelet production. Option B) Erythropoietin stimulates red blood cell production, not platelets. Option C) Filgrastim is a granulocyte colony-stimulating factor that primarily stimulates white blood cell production and is not indicated for platelet production. Educationally, it is important to understand the specific mechanisms of action of different medications to appropriately treat patients. In this case, knowing that Oprelvekin is a thrombopoietic growth factor helps in selecting the right medication to address the low platelet count caused by chemotherapy-induced bone marrow suppression. Understanding these concepts is crucial for healthcare providers to make informed decisions in patient care.