Pharmacist treatment support tool for oral sodium bicarbonate therapy in management of metabolic acidosis among chronic kidney disease patients

Abstract

Metabolic acidosis, a complication of chronic kidney disease (CKD), has garnered increasing attention due to emerging evidence supporting its treatment. Oral sodium bicarbonate (SB) is a potential treatment but discussion for its optimal use is still ongoing. In Malaysia, the availability of tablet and powdered forms adds complexity to treatment decisions for clinicians. The study aimed to develop a treatment support tool for pharmacists to enhance counselling on oral sodium bicarbonate therapy for CKD patients with metabolic acidosis. This study consisted of four studies. The first study was conducted retrospectively in three government hospitals to determine the prevalence and current management of metabolic acidosis among Malaysian CKD patients. Only 40.3% (265 out of 657) of patients had available bicarbonate levels, indicating inadequate monitoring of metabolic acidosis. The prevalence of metabolic acidosis in 259 CKD patients was high (n=223, 86.1%) with 43.0% (n=96) treated but only 19.8% (n=19) achieved targeted bicarbonate levels of ≥ 22mmol/L. The most common formulation was SB solution (n=91, 94.8%). The second study utilised a questionnaire to determine oral SB therapy acceptance and adherence among 203 patients from five government hospitals at one time point. Tablet users were more adherent compared to solution users (88.9% versus 70.9%, p=0.014) and had better acceptance scores exceeding 70% for five domains investigated (convenience, taste, appearance, efficacy and tolerability) compared to only three domains (convenience, taste and tolerability) above the same threshold for solution users. The third study, a quasi-experimental, conducted over 18 months, compared SB solution and tablets in terms of patient adherence, acceptance, safety (adverse events), and effectiveness (estimated glomerular filtration rate - eGFR decline), using standard care (SC) as the control. There was no significant difference for adherence and taste acceptance score between both SB formulations. Gastrointestinal related adverse events were significantly higher in SB group versus SC group (49.0% versus 4.0%, p<0.001). There was no significant difference in the mean (standard deviation, SD) eGFR decline for SB group compared to SC group (3.63 (6.14) ml/min/1.73m2 versus 3.77 (6.08) ml/min/1.73m2, p=0.932). The final study developed a treatment support tool based on findings from the three studies, validated with high content validity scores (average scale-level content validity index, S-CVI/Ave: 0.99 for monitoring, 1.00 for counselling) and strong face validity score (scale-level face validity index, S-FVI ≥ 0.83). In conclusion, this tool provides recommendations for pharmacists regarding patient monitoring and education, supporting effective counselling and appropriate therapy monitoring among CKD patients receiving oral sodium bicarbonate for metabolic acidosis treatment