Adjustments of medication dosages in patients with renal impairment in Botswana; findings and implications to improve patient care

Abstract

Background and aims: Medication dosage adjustments for renally impaired patients have not been studied in Botswana. This study was conducted to determine prescribing practices among patients with renal impairment in medical wards to improve future patient care. Methods: We conducted a retrospective study involving medical charts of patients admitted at a tertiary level hospital in Gaborone Botswana. Study participants included all patients admitted between August and October 2016 who were hospitalized for ≥24 hours. "Drug prescribing in renal failure: dosing guidelines for adults and children." was used to determine extent of dosage adjustments. A logistic regression model was used to assess which patient factors were associated with inappropriate dosage adjustment. Results: Twenty nine percent (233/804) of patients had renal impairment. Of these, 184 patients with renal impairment were included in the final analysis. There were 1143 prescription entries, of which 20.5% (n=234) required dosage adjustment for renal function but only 45.7% (n=107) were adjusted correctly. Of note, 112 patients were prescribed at least one drug that required dosage adjustment and only 30.4% (n=34) patients had all of their medications appropriately adjusted. Patient factors associated with inappropriate dosage adjustment included a higher number of medicines being prescribed. Mortality among patients with renal impairment was independently associated with higher scores of Charlson comorbidity index and hospital stay duration of 1-7 days. Conclusion: The renal function status of patients was not sufficiently taken into account when prescribing medicines especially in patients with severely impaired kidney function in Botswana. Continuous medical education needs to be encouraged to address this, which is being implemented. We will be following this up in future studies.

Medicine Dose Adjustment Practice and Associated Factors among Renally Impaired Patients in Amhara Regional State, Ethiopia

“…Although an eGFR of <59 mL/min/1.73 m 2 was used in their study to define renal impairment compared to eGFR ≤60 mL/min/1.73 m 2 used in our study, the prevalence of renal impairment was less. The definition of renal impairment varies among different information sources [ 10 ]. However, medicine dosing guidelines are typically derived from studies performed in patients with stable, chronic renal insufficiency and the recommendations are extrapolated to seriously ill patients with acutely decreased renal function [ 25 ].…”

“…For the purpose of this study to evaluate the appropriateness of medicine dosing adjustment, renal impairment was defined as estimated GFR ≤60 ml/min/1.73 m 2 [ 24 ]. The possible explanation for this discrepancy may be due to the current increasing number of patients visiting hospitals and the prevalence of renal impairment increases in an alarming rate [ 31 ], which is less prevalent than recent study done in Botswana that showed 29% [ 10 ]. This may be attributed to the fact that we used estimated GFR, rather than a SrCrto-defined renal impairment.…”

“…The total number of prescriptions that required dose adjustment and the percentage of inappropriate dosing varied in different studies [ 1 , 2 , 10 , 12 , 26 , 27 , 32 ]. The current study showed that 51.2% of the medicines that required adjustment were not adjusted appropriately; only 48.8% had correctly recommended doses, in line with a study conducted in Addis Ababa, Ethiopia, which reported that from 372 prescriptions, 51% prescription entries requiring dose adjustment were found to be in appropriate [ 12 ], and in Mekelle, Ethiopia, among 360 orders that need adjustment 51% were inappropriate [ 32 ].…”

“…Data were collected by a pretested interviewer-administered structured questionnaire. The questionnaire was prepared by the investigators after reviewing different literatures [ 10 , 12 , 26 – 28 ]. Five trained BSc: nurses participated in the data collection process where three of them were data collectors and two of them were supervisors.…”

“…Many side effects of medicines are poorly tolerated by patients with renal impairment and some medicines ceasing to be effective when renal function is reduced [ 9 ]. Therefore, when prescribing medicines for patients with kidney disease, multiple factors must be taken into account [ 10 ]. Among these, dose adjustment of medicines is an accepted standard of practice [ 11 ].…”