Rhabdomyolysis-induced acute kidney injury in a patient with non-compliance to levothyroxine therapy

SUMMARY: Hypothyroidism is a common medical condition and is often easily managed with excellent outcomes, when treated adequately. Compliance with levothyroxine (LT4) therapy is often compromised because of the need for a daily and lasting schedule. Overt rhabdomyolysis due to under-treatment or non-compliance is a rare occurrence. We report a case of rhabdomyolysis leading to acute kidney injury (AKI) on chronic kidney disease (CKD) requiring hemodialysis (HD) in a 68-year-old Caucasian male due to non-compliance with levothyroxine (LT4) therapy. Our patient 'ran out of levothyroxine' for approximately 4 weeks and developed gradually progressive muscle pain. The diagnosis of severe AKI due to rhabdomyolysis was made based on oliguria, elevated creatinine kinase (CK), and renal failure. Resuming the home dose of LT4 failed to correct CK levels, and there was a progressive decline in renal function. Although increasing doses of LT4 and three cycles of HD improved CK levels, they remained above baseline at the time of discharge. The patient recovered gradually and required HD for 4 weeks. CK levels normalized at 6 weeks. Through this case report, we highlight that non-compliance with LT4 therapy can lead to life-threatening complications such as renal failure and hence the need to educate patients on the significance of compliance with LT4 therapy should be addressed. LEARNING POINTS: Non-compliance to levothyroxine therapy is common and can lead to serious complications, including rhabdomyolysis. Rhabdomyolysis is an uncommon presentation of hypothyroidism and severe rhabdomyolysis can result in renal failure requiring hemodialysis. Rhabdomyolysis associated with hypothyroidism can be further exacerbated by concomitant use of statins.