Prescribing patterns of non-steroidal anti-inflammatory drugs in patients with chronic kidney disease

Abstract

The main aim of this study was to characterise the prescribing patterns of non-steroidal anti-inflammatory drugs (NSAIDs) in chronic kidney disease (CKD) patients in the private health sector of South Africa. This was done after determining the prevalence of the disease (CKD) in the private health sector. A quantitative, descriptive drug-utilisation review (DUR) was performed during the empirical investigation by using retrospective medicine claims data obtained from a pharmaceutical benefit management company (PBM). The study population consisted of all patients registered on the database with an ICD-10 code for CKD (N18) during the study period of 1 January 2009 to 31 December 2013. The number of CKD patients identified over the study period ranged from 1 017 to 1 158 and represented 0.10 to 0.14% of the total number of registered beneficiaries included in the database. The patients were predominantly male (male-to-female ratio 1:0.8) (p=0.668; Cramer’s V=0.021), whereas the 35–64-year age group indicated the highest CKD prevalence rates (p=0.014; Cramer’s V=0.039) with a mean age ranging from 59.7 ± 16.8 (95% CI 58.7;60.7) years in 2009 to 57.8 ± 16.1 (95% CI 56.9;58.8) years in 2013. There were several chronic conditions that co-occurred with CKD, with hypertension being the most prevalent, occurring in more than half the CKD patients. Other prevalent chronic conditions co-occurring with CKD included hyperlipidaemia (36 to 43%) and diabetes mellitus type 2 (19 to 25%). No practically significant associations were found between CKD prevalence and the patient’s age or gender. Non-steroidal anti-inflammatory drugs were prescribed in 26% (n=309) to 40% (n=492) of the CKD patients from 2009 to 2013. The mean number of NSAID items per CKD patient ranged from 2.4 ± 2.67 (95% CI 2.1;2.6) in 2009 to 1.9 ± 1.2 (95% CI 1.7;1.9) in 2013. No association was found between gender and CKD patients who received NSAIDs vs. those who did not (p<0.05; Cramer’s V<0.01). A weak association was found between CKD patients who used NSAIDs vs. those who did not and age groups (p<0.05; Cramer’s V≥0.1). The NSAID that was prescribed the most was diclofenac (34.3%), followed by the COX-2 inhibitors celecoxib (18.8%), meloxicam (19.5%) and etoricoxib (9.5%). The NSAIDs were mostly prescribed in dosages similar to and even exceeding the recommended daily dosage for these NSAIDs in patients with normal kidney function. Non-steroidal anti-inflammatory drugs that were regularly prescribed in dosages greater than the recommended daily dosage were ibuprofen (44.9%), indomethacin (39.1%) and diclofenac (12.8%). The general medical practitioners were responsible for prescribing NSAIDs most frequently, with 61.6% of the NSAID items prescribed. In conclusion this study determined that CKD has several chronic conditions co-occurring with it, which should be accounted for when treatment and management of disease is being considered. Secondly, nephrotoxic drugs (NSAIDs) are frequently prescribed to patients who have a reduced renal function. There is no difference between the dosages at which these drugs are prescribed to CKD patients and the recommended daily dosages of these drugs in patients with healthy kidneys. Further research should be conducted to improve pain management in CKD patients.