Aminoglycoside prescription, therapeutic monitoring and nephrotoxicity at a university hospital in Saudi Arabia.

We studied the use of aminoglycosides at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia, including prescriptions, dosage, serum levels, toxic factors and treatment outcome. Two hundred and fifty-six patients on aminoglycosides were involved in the study period November-December 1994: 24 (9.4%) patients were on amikacin and 232 (90.6%) patients were on gentamicin. The serum concentration was below the therapeutic range in 75% of the patients on amikacin and 50% on gentamicin. Serum concentrations within the therapeutic range (> 20 micrograms/ml; < 35 micrograms/ml for amikacin, and > 6 micrograms/ml and < 10 micrograms/ml for gentamicin) were achieved in 4% and 44% of patients respectively. The dosage was adjusted during therapy for 57% of the patients because of low levels, and for 43% of the patients because of toxic levels. More than 30% of the patients had their serum monitored for the first time 3 days after starting aminoglycoside therapy. Aminoglycosides were discontinued before the end of the course in 157 (62%) patients because 24% of them had developed toxic levels and 24% had not responded to the treatment. Successful outcome was achieved in 170 (66%) of the patients, however, 50% of them had inappropriate serum levels. The risk factors that are significantly associated with aminoglycoside nephrotoxicity were duration of therapy (P = 0.008), renal, liver diseases and ampicillin given concurrently with the aminoglycosides (P = < 0.05).