Ibuprofen-induced distal (type 1) renal tubular acidosis and hypokalaemia: the dangers of ibuprofen-codeine combination over-the-counter preparations

Ibuprofen-Induced Renal Tubular Acidosis: Case Report on a Not-So-Basic Clinical Conundrum

Rationale

Renal tubular acidosis (RTA) is a cause of non-anion gap metabolic acidosis (NAGMA) that is infrequently diagnosed and is due to various underlying etiologies that impair the kidney's ability to retain bicarbonate or excrete acid. Ibuprofen is an over-the-counter non-steroidal anti-inflammatory medication that is used by patients widely for a variety of reasons. Although it is well known that ibuprofen and other non-steroidal anti-inflammatory drugs may have nephrotoxic effects, the role of ibuprofen as a cause of RTA and hypokalemia is not well recognized.

Presenting Concerns

A 66-year-old man with chemotherapy-treated lymphoma in remission and ongoing heavy ibuprofen use for chronic pain presented to hospital with a 1-week history of increasing lethargy and otherwise unremarkable review of systems. Investigations showed acute kidney injury, hypokalemia, hyperchloremia, and NAGMA with elevated urinary pH and positive urine anion gap.

Diagnoses

The final diagnosis of distal RTA secondary to ibuprofen was made after ruling out gastrointestinal bicarbonate loss and additional secondary causes of RTA, including other medications, autoimmune conditions, and obstructive uropathy.

Interventions

The patient was admitted and treated with intravenous sodium bicarbonate for 24 hours with correction of hypokalemia via oral supplementation. His ibuprofen-containing medication was discontinued.

Outcomes

His acute kidney injury and electrolyte abnormalities resolved within 48 hours of initiating treatment with concurrent resolution of his lethargy. He was discharged home and advised to stop taking ibuprofen.

Lessons Learned

We report a case of patient with hypokalemia and NAGMA secondary to ibuprofen and highlight the importance of monitoring for this side effect in patients taking ibuprofen.

Ibuprofen-Associated Hypokalemia and Metabolic Acidosis: Systematic Literature Review

OBJECTIVE

Ibuprofen is a widely used nonsteroidal anti-inflammatory drug, which has been occasionally associated with hypokalemia and metabolic acidosis. The objective of this report is to analyze the literature on this issue and to address the underlying pathophysiology.

DATA SOURCES

Excerpta Medica, the National Library of Medicine, and Web of Science were searched from inception to July 16, 2021.

STUDY SELECTION AND DATA EXTRACTION

Papers reporting individually documented humans on ibuprofen with hypokalemia, acidosis, or both were retained. Data were extracted using a checklist.

DATA SYNTHESIS

For the final analysis, we evaluated 41 reports describing 50 cases (26 males and 24 females; 36 adults and 14 children) with often profound hypokalemia, acidosis, or both after ingestion of ibuprofen. Twenty-six cases were acute and 24 long term. Hypokalemia and acidosis occurred not only after ingestion of very high doses but also after ingestion of moderately high or even normal doses of ibuprofen. Laboratory values consistent with an excessive urinary potassium excretion or an altered urinary acidification were often disclosed in most cases. Discontinuation of ibuprofen resulted in a resolution of hypokalemia and acidosis within days in 47 cases. The course was lethal in 3 cases.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review highlights potentially fatal side effects of ibuprofen and can help doctors who are confronted with such a situation.

CONCLUSIONS

These data highlight the potential of ibuprofen to occasionally induce hypokalemia and acidosis of renal origin. Discontinuation of ibuprofen results in a resolution within days.

Renal Tubular Acidosis and Management Strategies: A Narrative Review

Renal tubular acidosis (RTA) occurs when the kidneys are unable to maintain normal acid−base homeostasis because of tubular defects in acid excretion or bicarbonate ion reabsorption. Using illustrative clinical cases, this review describes the main types of RTA observed in clinical practice and provides an overview of their diagnosis and treatment. The three major forms of RTA are distal RTA (type 1; characterized by impaired acid excretion), proximal RTA (type 2; caused by defects in reabsorption of filtered bicarbonate), and hyperkalemic RTA (type 4; caused by abnormal excretion of acid and potassium in the collecting duct). Type 3 RTA is a rare form of the disease with features of both distal and proximal RTA. Accurate diagnosis of RTA plays an important role in optimal patient management. The diagnosis of distal versus proximal RTA involves assessment of urinary acid and bicarbonate secretion, while in hyperkalemic RTA, selective aldosterone deficiency or resistance to its effects is confirmed after exclusion of other causes of hyperkalemia. Treatment options include alkali therapy in patients with distal or proximal RTA and lowering of serum potassium concentrations through dietary modification and potential new pharmacotherapies in patients with hyperkalemic RTA including newer potassium binders.

Ibuprofen Overuse Leading to Life-threatening Hypokalemia Associated with Renal Tubular Acidosis in Two Patients

Ibuprofen is a commonly used medication in the United States and is used both by prescription and over the counter, while hypokalemia is a life-threatening condition caused by various etiologies, one of which is the side effect of medications. Ibuprofen is well-known for its various nephrotoxic side effects, including hyperkalemia as a common electrolyte abnormality, however, renal tubular acidosis leading to hypokalemia with the use of ibuprofen has been reported rarely. We present here two cases of life-threatening hypokalemia due to over-the-counter use of large doses of ibuprofen and describe its management.

Impaired consciousness, hypokalaemia and renal tubular acidosis in sustained Nurofen Plus abuse

Ibuprofen-induced renal tubular acidosis is a rare but important diagnosis which should be considered in patients presenting with hypokalaemia and metabolic acidosis. This case report details the case of a 33-year-old woman presenting with reduced conscious state, metabolic acidosis and profound hypokalaemia without an obvious cause. With correction of the patient’s electrolyte and acid-base disturbance, her conscious state improved allowing disclosure of her use of Nurofen Plus for its euphoric opiate effects. The diagnosis of renal tubular acidosis had been considered and subsequent disclosure of excessive chronic ingestion of ibuprofen suggested this to be the underlying cause. The striking feature of our patient was the insidious development of the problem and delayed accurate drug history. An important safety message arising from our case is the composite risk of dependence on the opiate component of over the counter analgesics, such as Nurofen Plus, and adverse events related to the ibuprofen component.