A Comparative Study Assessing the Incidence and Degree of Hyperkalemia in Patients on Unfractionated Heparin versus Low-Molecular Weight Heparin.

BACKGROUND

Heparin and its derivates, including unfractionated heparin (UFH) and low molecular weight heparin (LMWH), are among the most commonly used anticoagulants. Nonetheless, their use has been associated with hyperkalemia.

OBJECTIVE

To determine and compare the incidence, magnitude, and potential risk factors of hyperkalemia in patients receiving UFH versus LMWH in a real-world clinical setting.

METHODS

A retrospective observational study was conducted involving all adult hospitalized patients who received UFH, dalteparin or enoxaparin. Electronic medical records were reviewed over a 12-month period, collecting data on demographic, laboratory, comorbidity, and medication-related variables. Data were analyzed using multivariate logistic regression.

RESULTS

A total of 929 patients met the eligibility criteria, with a mean age of over 40 years across all groups. Of these, 56.3%, 17.2%, and 15.7% experienced hyperkalemia with UFH, dalteparin and enoxaparin, respectively. The incidence of hyperkalemia was significantly higher with UFH compared to enoxaparin and dalteparin (p<0.001). Diabetes mellitus was associated with a higher incidence of hyperkalemia (OR 1.79, 95% CI 1.241-2.581, p=0.002), as was the concomitant use of co-trimoxazole (OR 2.244, 95% CI 1.137-4.426, p=0.02). Whilst chronic kidney disease and the use of two or more hyperkalemia-inducing agents were not statistically significant, they were retained in the model as they were associated with more than a 10% increase in the odds of hyperkalemia.

CONCLUSION

Heparin (UFH, LMWH) administration was associated with a risk of hyperkalemia particularly in patients with diabetes mellitus and those concurrently receiving co-trimoxazole.