What route can ondansetron be given? (select all that apply)

Correct Answer: A

Rationale: Ondansetron, which is commonly used to prevent nausea and vomiting, can be administered via three routes: Orally (PO), Intravenously (IV), and Rectally (Rectal). These routes allow for flexible administration based on the patient's condition and needs. Intramuscular (IM) administration is not a recognized route for ondansetron administration.

Correct Answer: A

Rationale: Ciclosporin is extensively metabolized by CYP3A enzymes, making it susceptible to drug interactions with inhibitors or inducers of this pathway.

Correct Answer: C

Rationale: Lithium, used for bipolar disorder, stabilizes mood via inositol depletion and other mechanisms. It can cause hypothyroidism, not hyperthyroidism, by inhibiting thyroid hormone release. High sodium intake increases lithium excretion, lowering plasma levels, not raising them. Common adverse effects include acne (sebaceous gland stimulation), polydipsia, and polyuria (due to nephrogenic diabetes insipidus from ADH antagonism), affecting many patients and requiring monitoring. Teratogenicity concerns focus on Ebstein's anomaly (cardiac defect), not spina bifida, though risks are low with modern management. Sedation isn't rapid; therapeutic effects take days to weeks. The constellation of acne, polydipsia, and polyuria reflects lithium's broad physiological impact, making it the most accurate description of its side effect profile.

Correct Answer: B

Rationale: Erythromycin is a suitable alternative for patients allergic to penicillin. Erythromycin belongs to the macrolide class of antibiotics and is effective against a wide range of bacterial infections. It is generally well-tolerated and can be used as an alternative in cases of penicillin allergy.cephalosporins, tetracyclines, sulfonamides, and aminoglycosides like gentamicin should not be prescribed to a patient with a known penicillin allergy as they can potentially cross-react and cause allergic reactions.

Correct Answer: C

Rationale: Methotrexate is a drug commonly used in cancer chemotherapy due to its ability to inhibit the synthesis of DNA, RNA, and proteins necessary for cell reproduction. Unfortunately, methotrexate does not penetrate the blood-brain barrier well, which means it cannot effectively reach or treat central nervous system (CNS) diseases when administered through traditional routes like oral ingestion or intravenous injection.