RHABDOMYOLYSIS AFTER SUCCINYLCHOLINE USE IN AN ADULT FILIPINO: A RARE ADVERSE DRUG REACTION

Rhabdomyolysis is a potentially life-threatening condition characterized by skeletal muscle breakdown and release of intracellular contents such as creatine kinase (CK), myoglobin, and electrolytes into the circulation. While trauma and exertion are common causes, certain drugs, including neuromuscular blockers and statins, may precipitate the condition. Succinylcholine, a depolarizing neuromuscular blocker used for rapid sequence intubation, has been associated with hyperkalemia, arrhythmias, and malignant hyperthermia, but rhabdomyolysis remains a rare adverse effect in adults without neuromuscular disease. This study aims to describe a case of succinylcholine-induced rhabdomyolysis in an adult Filipino male and highlight its clinical presentation, diagnostic course, and management outcomes to increase awareness of this uncommon complication.

A 52-year-old Filipino male with hypertension, diabetes mellitus, dyslipidemia, and bronchial asthma underwent elective direct laryngoscopy under general anesthesia. Intravenous succinylcholine was administered during induction. The patient’s clinical course, laboratory results, and management were reviewed. Laboratory evaluation included serum creatine kinase, liver transaminases, and urinalysis for evidence of myoglobinuria. Imaging and other diagnostic tests were performed to exclude alternative causes. Treatment included withdrawal of potential myotoxic drugs, aggressive hydration, urine alkalinization, and electrolyte monitoring.

Within hours after surgery, the patient developed diffuse muscle pain and dark-colored urine. Laboratory studies showed markedly elevated CK, CK-MB, and liver enzymes, along with urinalysis findings of 3+ blood and protein, consistent with rhabdomyolysis. Renal function was initially normal, and imaging showed only benign prostatic hypertrophy. Statin therapy (rosuvastatin and ezetimibe) was discontinued due to potential contribution to muscle injury. Management involved aggressive intravenous hydration, sodium bicarbonate for urine alkalinization, and calcium carbonate supplementation. Over six days, the patient’s urine color normalized, CK levels decreased steadily, and no acute kidney injury developed. Other possible causes including trauma, exertion, malignant hyperthermia, inflammatory myopathies, and viral infections were ruled out based on clinical and laboratory findings. The temporal association with succinylcholine administration and absence of other triggers strongly supported the diagnosis of succinylcholine-induced rhabdomyolysis, possibly potentiated by concurrent statin use.

This case demonstrates that succinylcholine, although widely used and generally safe, can cause rhabdomyolysis even in adults without underlying neuromuscular disorders. The purpose of reporting this case is to raise awareness of this rare but serious complication and emphasize the importance of individualized anesthetic planning, especially for patients on chronic statin therapy or other myotoxic drugs. Early recognition through monitoring for postoperative muscle pain, weakness, or dark urine, followed by prompt laboratory assessment and supportive management, can prevent renal failure and other life threatening sequelae. Further studies are warranted to elucidate the mechanisms, risk factors, and preventive strategies for succinylcholine-associated rhabdomyolysis in adults.