This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Pharmacology), Subject name: Pharmacology
Drug monitoring is required for the following 
Select and explain. 
A. Lithium, B. Paracetamol, C. Ampicillin, D. Olanzapine
A: Lithium
Answer: A: Lithium 
Explanation: (A) Lithium# Lithium is generally taken with food, although its absorption is not markedly affected by the presence of food.> Doses vary widely and are adjusted based on measurements of the levels of lithium in the blood.> Early in therapy, dose adjustments are made as often as every 5 to 7 days to establish the correct dose.> Patients with kidney diseases excrete less lithium from the body and, therefore, require lower doses.