Professor Department of Pharmacy Practice, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Mysore-570 015. India Mysuru, India
Background: Narrow therapeutic index drugs (NTIDs) have small margin for dosing adjustment; irrational prescribing of NTIDs may lead to unwanted or life-threatening adverse drug reactions (ADRs).
Objectives: To determine utilization pattern of narrow therapeutic index drugs in a tertiary care teaching hospital
Methods: A prospective review of the treatment charts of patients admitted to the department of general medicine, cardiology, neurology, and paediatrics and receiving at least one NTID was carried for a period of six months in a tertiary care teaching hospital. The list of NTIDs was prepared through literature review. Defined daily dose (DDD) was calculated and all other necessary information was collected from the patients’ case sheet. Drug utilization evaluation (DUE) principles were adapted to study the use of NTIDs and WHO prescribing indicators were adapted to assess the quality of prescribing. The data obtained were assessed categorically and represented as [n (%)].
Results: A total of 120 patients receiving at least one NTIDs were identified during the study period. The total number of drugs prescribed during the study period were 1192 drugs, out of which 210 were NTIDs. The study found that Rifampin was the most frequently prescribed NTID, with a DDD of 18,000/1000 patient days, followed by insulin at 6065.49/1000 patient days and levothyroxine at 5372.55/1000 patient days. The average number of co-morbidities per patient was 1.62, and the average hospital stay was 7.44 days. The average number of drugs per encounter was 1.75; percentage of encounter with an antibiotic prescribed was 11.67. Percentage of encounters with an injection was 76.67. Only 12.85% of the drugs were prescribed by generic names, while 91.90% of the prescriptions were from the essential drug list.
Conclusions: NTIDs demand low margin of error and clinical pharmacist assists in rational prescribing of NTIDs which helps in reduction of NTIDs induced morbidities and mortalities. Comprehensive study on determining utilization pattern of NTIDs not only helps in ensuring rational drug use but also promotes patient safety.
