Neuromuscular Effects of Rocuronium Bromide in Patients in Statin Therapy for at least Three Months

Statins cause skeletal muscle myopathy. However, the neuromuscular effects of non-depolarizing neuromuscular-blocking agent in patients in long-term statin therapy remain unclear. Hence, we investigated the neuromuscular effects of rocuronium and muscle injury in patients in long-term statin therapy. Eighteen statin users using statins for at least 3 months were included in the statin group and 18 non-statin users were included in the non-statin group. General anaesthesia was induced with intravenous midazolam, etomidate, sufentanil and rocuronium 0.9 mg/kg (3ED₉₅ ) for intubation. Anaesthesia was maintained with 1% propofol and remifentanil. The onset time and duration 10% T₁ and 25% T₁ of rocuronium were recorded. Blood samples were obtained before induction and 5 min., 1 hr, 2 hr, 4 hr, 12 hr and 24 hr after rocuronium administration to measure creatine kinase (CK), myoglobin and potassium. Myalgia was determined at 2 and 24 hr after surgery. There were no significant differences in the basic clinical characteristics between the two groups. The onset time of the statin group was significantly shorter than that of the non-statin group (p = 0.02), while the duration 10% T₁ and duration 25% T₁ of the statin group were significantly longer than those of the non-statin group (p = 0.006; p = 0.045). The myoglobin and CK concentrations increased after rocuronium administration as compared to baseline in both groups. CK concentration in the statin group was significantly higher than in the non-statin group just at 24 hr (p = 0.000003). However, myoglobin showed no significant difference between the two groups. The onset time of rocuronium decreases and its duration time increases in patients in long-term statin therapy.