Indication for calcium administration is:

Correct Answer: B

Rationale: Step-by-step rationale: 1. Calcium administration is indicated in malabsorption of vitamin D because vitamin D is necessary for calcium absorption in the intestine. 2. Malabsorption of vitamin D leads to decreased calcium absorption, which can result in calcium deficiency. 3. Administering calcium can help compensate for the decreased absorption of calcium due to vitamin D malabsorption. Summary: - Option A is incorrect as the formation of vitamin D in the skin is not directly related to calcium administration. - Option C is incorrect as hypercalcemia of malignancy indicates excess calcium, not a need for calcium administration. - Option D is incorrect as it mentions the deficiency of vitamin D, not the malabsorption of vitamin D, which is the indication for calcium administration.

Correct Answer: D

Rationale: Step-by-step rationale for why answer D is correct: 1. Vancomycin is a glycopeptide antibiotic known to inhibit cell wall synthesis. 2. It is effective against Gram-positive bacteria such as Staphylococcus and Streptococcus. 3. Vancomycin is not active against Gram-negative bacteria due to differences in cell wall structure. 4. Options A, B, and C are incorrect as they provide inaccurate information about vancomycin's characteristics.

Correct Answer: A

Rationale: Certainly! Chloroquine is the correct answer for malaria chemoprophylaxis and treatment because it is effective against Plasmodium species. It acts by accumulating in the parasite's food vacuole, interfering with heme polymerization. This prevents the parasite from utilizing hemoglobin and ultimately leads to its death. Quinidine and quinine are primarily used for severe malaria treatment. Sulfonamides are not commonly used for malaria treatment due to resistance issues and their limited efficacy against Plasmodium species.

Correct Answer: B

Rationale: The correct answer is B: Zalcitabine. Zalcitabine is a nucleoside reverse transcriptase inhibitor commonly associated with peripheral neuropathy and oral ulceration as side effects. These adverse effects are well-documented in clinical studies and are known to be dose-dependent. Zalcitabine can cause damage to peripheral nerves leading to neuropathy and can also irritate the mucous membranes in the mouth causing oral ulceration. Incorrect Choices: A: Acyclovir - Acyclovir is an antiviral medication used to treat herpes infections and does not typically cause peripheral neuropathy or oral ulceration. C: Zidovudine - Zidovudine is also a nucleoside reverse transcriptase inhibitor used in the treatment of HIV, but it is not associated with peripheral neuropathy or oral ulceration. D: Saquinavir - Saquinavir is a protease inhibitor used to treat HIV and does not commonly induce peripheral neurop

Correct Answer: D

Rationale: Correct Answer: D Rationale: 1. Hypermagnesemia can exacerbate heart failure. 2. Vomiting may further worsen magnesium levels. 3. Digoxin toxicity is a concern in hypermagnesemia. 4. Discontinuing digoxin is crucial to avoid adverse effects. 5. Starting losartan can help manage heart failure without worsening hypermagnesemia. Summary: A: Adding potassium may worsen hypermagnesemia. B: Atropine is not indicated for hypermagnesemia or heart failure. C: Increasing furosemide may lead to electrolyte imbalances. D: Discontinuing digoxin and starting losartan is the appropriate therapeutic adjustment.