Hyperkalaemia with cyclooxygenase-2 inhibition and hypoaldosteronism

The association between nonsteroidal anti-inflammatory drugs and potassium concentrations: A pharmacoepidemiological study in Saudi Arabia

OBJECTIVE

Several nonsteroidal anti-inflammatory drugs (NSAIDs) have been linked to cardiac death. The mechanism that is responsible for this adverse effect appears to be ischemic insult; however, another possible mechanism involves hyperkalemia. The objective of the present study was to determine the feasibility of conducting pharmacoepidemiological studies in Saudi Arabia using refill prescription data to investigate the association between NSAIDs and increased serum potassium concentrations.

METHODS

This retrospective cohort study included patients from an academic medical center in Riyadh, Saudi Arabia. The patients who were recently prescribed NSAIDs were compared to a control group of paracetamol users, with respect to the drugs' effects on serum potassium concentrations. The covariates that affected the potassium concentration or the use of NSAIDs were controlled for in the analysis. The studied outcome was the first serum potassium concentration of more than 5 mEq/L.

RESULTS

A total of 184 patients were prescribed NSAIDs (n = 101) or paracetamol (n = 83) and met the inclusion criteria. Compared to the control group, the patients who received NSAIDs were more likely to be women, were less likely to use angiotensin-converting enzyme inhibitors, and were more likely to have lower baseline serum creatinine concentrations. The other baseline characteristics were similar between the patients in the NSAID group and the patients who received paracetamol. Compared to the patients who were prescribed paracetamol, those who were prescribed NSAIDs did not have an increased risk of hyperkalemia (odds ratio, 1.1, 95% confidence interval, 0.17-6.7, P = 0.95).

CONCLUSION

In the present, small feasibility study, no increase in the risk of hyperkalemia was associated with NSAIDs compared to paracetamol. The present study was exploratory and included only a small number of patients; therefore, this study may not be sufficiently powered to detect small differences between the groups. Future studies with larger sample sizes are needed to investigate the association between NSAIDs and hyperkalemia.

Risk of hyperkalemia associated with selective COX-2 inhibitors

BACKGROUND

Selective cyclooxygenase-2 (COX-2) inhibitors have been linked to cardiac death. The mechanism for this adverse effect appears to be by ischemic insult; however another mechanism could involve hyperkalemia. The objective of this study was to determine the effects of selective COX-2 inhibitors and non-selective nonsteroidal anti-inflammatory drugs (NSAIDs) on serum potassium concentration and the electrocardiogram.

METHODS

A retrospective cohort study was conducted using propensity score matching of patients from an inner-city academic medical center at Indianapolis, Indiana. Two hundred and two patients prescribed selective COX-2 inhibitors were matched to 202 patients prescribed non-selective NSAIDs using propensity scores methods. Outcomes included change in serum potassium concentration from baseline and the risk of an abnormal electrocardiogram.

RESULTS

Compared to patients prescribed non-selective NSAIDs, those prescribed a selective COX-2 inhibitor had a higher risk of serum potassium increase greater than 5 mEq/L (OR, 2.56; 95%CI, 1.03-6.36). However, patients prescribed selective COX-2 inhibitors had no greater risk of electrocardiogram abnormality (OR, 1.16; 95%CI, 0.74-1.82).

CONCLUSIONS

Selective COX-2 inhibitors may have a greater risk of hyperkalemia than non-selective NSAIDs. This study was exploratory with small numbers of patients. Further studies are needed to confirm these results and any association with cardiovascular events.

Etoricoxib-induced life-threatening hyperkalemia and acute kidney dysfunction against the background of telmisartan and a low sodium diet

Drug-induced hyperkalemia is not uncommon and may be life-threatening when presenting acutely in the emergency department. We present a case of severe hyperkalemia precipitated acutely by etoricoxib in a patient who was on telmisartan and a low sodium (potassium chloride-rich) diet. A 75-year-old male with a past medical history of well-controlled diabetes and hypertension was prescribed etoricoxib (90 mg daily) for 3 days for musculoskeletal backache. He had been taking his routine medications including telmisartan and a potassium-rich salt substitute for many years, without any recent change in dosage or quantity. There was evidence of microalbuminurea; however, the renal functions and electrolytes prior to starting etoricoxib were normal. He presented to the emergency department with signs and symptoms of life-threatening hyperkalemia (serum potassium 7.7 mEq/dl), accelerated hypertension, congestive heart failure, pulmonary edema and acute renal failure. Acute medical management and withholding all drugs that could cause hyperkalemia improved his serum potassium levels over 24 h and renal parameters within 5 days. All the other drugs except etoricoxib were restarted under observation over 8 weeks with no recurrence of the acute episode. Non-steroidal analgesics and other COX-2 inhibitors (rofecoxib and celecoxib) have been known to precipitate renal failure and hyperkalemia specially in patients at risk for the same; although not unexpected, this may be the first reported case of life-threatening hyperkalemia precipitated by etoricoxib in a previously stable patient having increased risk of renal failure and hyperkalemia.