A 20 year old patient presented to the ER with headache, stiff neck and fever * for 3 days and is diagnosed with bacterial meningitis. Which one of the following antibiotics is the best choice to treat meningitis?

Correct Answer: C

Rationale: The correct answer is C: Cefotaxime. This third-generation cephalosporin is a preferred choice for treating bacterial meningitis due to its broad-spectrum coverage against common pathogens causing meningitis, including Streptococcus pneumoniae and Neisseria meningitidis. Cefuroxime (A) and Cephalexin (B) are not optimal choices as they have less activity against these pathogens. Cefdinir (D) is not a recommended treatment for bacterial meningitis and is not as effective as Cefotaxime in this scenario.

Correct Answer: C

Rationale: The correct answer is C: Primaquine. Primaquine is an 8-aminoquinoline antimalarial drug primarily used for the radical cure of Plasmodium vivax and Plasmodium ovale malaria, not for prophylaxis. Rationale: 1. Primaquine is not recommended for prophylactic use due to its potential for causing hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. 2. Pyrimethamine + sulfadoxine (Choice A) is a combination drug used for both treatment and prophylaxis of malaria. 3. Proguanil (Choice B) is used for prophylaxis of malaria in combination with other antimalarial drugs. 4. Mefloquine (Choice D) is used for both treatment and prophylaxis of malaria, especially in areas with chloroquine-resistant strains.

Correct Answer: B

Rationale: The correct answer is B: Ciprofloxacin. Ciprofloxacin is a fluoroquinolone antibiotic that inhibits bacterial DNA gyrase, an enzyme crucial for bacterial DNA replication and repair. By interfering with DNA function, it disrupts bacterial growth and can effectively treat most cases of uncomplicated gonorrhea. Rationale: A: Chloramphenicol inhibits protein synthesis, not DNA function. C: Streptomycin inhibits protein synthesis by binding to the bacterial ribosome. D: Erythromycin also inhibits bacterial protein synthesis and is not primarily targeted at DNA function.

Correct Answer: C

Rationale: The correct answer is C: Suramin. Suramin is the drug of choice for treating Chaga's disease caused by Trypanosoma cruzi. It is a specific drug that targets the parasite responsible for the disease. Nifurtimox is used for acute Chaga's disease, not chronic cases like in this patient. Metronidazole is not effective against Trypanosoma cruzi. Chloroquine is used for treating malaria, not Chaga's disease. Therefore, the most appropriate drug for this patient is Suramin.

Correct Answer: B

Rationale: The main reason for using combination therapy in tuberculosis treatment is to delay or prevent the emergence of resistance. By using multiple drugs that target different aspects of the bacteria's life cycle, it becomes harder for the bacteria to develop resistance to all drugs simultaneously. This helps to ensure that the treatment remains effective in the long term. Explanation for other choices: A: While combination therapy can sometimes help reduce side effects by using lower doses of each drug, the primary reason for using it in tuberculosis treatment is to prevent resistance, not side effects. C: While combination therapy can increase antimycobacterial activity, the main goal is to prevent resistance, not to enhance the drugs' effects. D: Providing prophylaxis against other bacterial infections is not the main reason for using combination therapy in tuberculosis treatment; the focus is on preventing resistance.