Understanding of the biochemical and physiological effects of drugs in patients with renal disease is of vital importance. With progression of renal disease, alterations in drug pharmacokinetics occur, resulting in changes in bioavailability, distribution, metabolism and handling of drugs. To optimize therapy and reduce the risk of toxicity, it is important to understand the changes in pharmacokinetics brought on by loss of renal function in children. Pharmacotherapy is an integral part of management of renal disease. 2 It may be either given to treat the primary underlying condition precipitating the renal disease or it may be given to preserve renal function and protect from incident complications. Drugs can be administered either orally or by the parenteral route. They gain access to the systemic circulation where they bind to plasma proteins. In the disease state, drug bioavailability and absorption may be decreased due to the altered milieu in the gastrointestinal tract. Nausea and vomiting secondary to worsening disease may impair contact time between the drug and the lining mucosa.