OBJECTIVES : Polypharmacy, the concomitant use of 5 or more medications, is highly prevalent among older adults and individuals with multimorbid conditions and has been linked to suboptimal clinical outcomes in various diseases. However, little is known about the impact of polypharmacy on clinical outcomes among COVID-19 patients. This systematic review summarizes available literature on the association between polypharmacy and specific drug classes, and clinical outcomes among COVID-19 patients.

METHODS : We conducted an electronic database search on Embase, Medline, Cochrane, Scopus, Google Scholar, clinicaltrials.gov, LITCOVID, PubMed, PubMed Central (PMC), and China national Knowledge infrastructure (CNKI) for studies on Polypharmacy among COVID-19 patients using relevant combinations of the keywords. Only studies published between November 2019 to September 2020 were included. We adopted the PRISMA guideline in conducting and reporting this systematic review.

RESULTS : Only seven articles out of 1,502 were eligible for inclusion. Across all studies, the total sample size was 474,342, out of which 10,519 (2.22%) patients tested positive for SARs-CoV-2 and a total of 4,818 (45.8%) COVID-19 positive patients experienced polypharmacy. Five out of the seven studies included found associations between polypharmacy and negative clinical outcomes among COVID-19 patients. Polypharmacy significantly (p<0.01) increased relative risk of a positive COVID-19 test result and was associated with death among male COVID-19 patients (p<0.001), while severe COVID-19 significantly increased the rate of acute kidney injury (p=0.003) and adverse drug reaction (ADRs) (p<0.001). Antipsychotic drug class was associated with severe COVID-19 (OR=2.79 95%CI=2.23-3.49) and increased risk of death among COVID-19 infected men (OR=1.71; 95% CI: 1.18–2.48) and women (OR=1.96; 95% CI=1.41–2.73).

CONCLUSIONS : Polypharmacy and selected drug classes are associated with increased risk of adverse clinical outcomes among COVID-19 patients. Understanding these relationships would enhance risk stratification and evidence-based decision making that would help improve care and clinical outcomes of vulnerable to severe COVID-19 patients.