Clinical Experience of Use of Kampo Medicine Shakuyakukanzoto for Muscle Spasms Caused by Tetanus

Background Tetanus is an infectious disease caused by Clostridium tetani, which produces tetanospasmin. Intensive care using sedatives and muscle relaxants is required for the management of severe tetanus, however, long-term use of those medicines is associated with the occurrence of post-intensive care syndrome (PICS). Shakuyakukanzoto (SKT), which is clinically used for the treatment of pain associated with sudden myospasm widely, is one of Kampo medicines, and some studies showed that they are effective in treating muscle spasms caused by tetanus. The purpose of this study is to evaluate the usefulness of SKT in the management of tetanus patients from the viewpoint of the reduction of sedatives. Methods Patients who were diagnosed with tetanus and were treated in our hospital between January 2006 and December 2022 were included. Patients were divided into two groups, patients treated with SKT and those without SKT, and the background information and clinical courses, especially the reduction of sedatives, were compared between the two groups. Results There were five tetanus patients who were treated with SKT (SKT(+) group) and two tetanus patients without SKT (SKT(-) group), respectively. Intubation and mechanical ventilation were required for the management of generalized seizures in all seven patients, who were admitted to the intensive care unit (ICU). The administration of propofol could be discontinued after an average of 8.6 days (range: 3-22 days) from the initiation of SKT administration. The dosage of propofol was lower in patients who received SKT versus those who did not; midazolam and fentanyl exhibited a similar tendency. The mean durations of ICU and hospital stays for patients treated with or without SKT were almost equal (the mean durations of ICU stay in SKT(+) and SKT(-) groups were 22.6 and 24.0 days, and those of hospital stay in SKT(+) and SKT(-) groups were 35.2 and 36.0 days, respectively). All seven patients were discharged and transferred to another hospital for rehabilitation. Conclusions SKT may be useful in the management of myospasms in patients with tetanus. It may also prevent the occurrence of PICU in patients with tetanus who require intensive care by reducing the use of sedatives and analgesics.