Two cases of muscle cramp successfully treated with shichimotsukokato

To the editor: A muscle cramp is a sudden, spastic, and painful contraction of skeletal muscle, and patients with muscle cramp are frequently seen in clinics. Shakuyakukanzoto (SKT) is a representative Kampo medicine that effectively treats muscle cramps, but it contains a large amount of glycyrrhizin because one of its components is Glycyrrhizae radix. The high incidence of pseudoaldosteronism is therefore a major concern when SKT is used. Recently, we experienced two cases of muscle cramps successfully treated with the Kampo medicine shichimotsukokato (SCMKT), which does not contain Glycyrrhizae radix. Case 1 was a 61-year-old female whose complaint was a 3 month history of muscle cramp in both calves. She suffered from strong muscle cramps approximately three times per week, mainly at nighttime. She also experienced occasional cramping in her fingers or the soles of her feet. Her medical history included breast cancer and lymphedema of the left arm due to surgery. She noted that her skin had become dry, particularly on her hands. Her tongue was light red, with slight white fur. Her pulse was deep and weak. Her abdomen showed moderate abdominal strength accompanied by a slight tympanic sound. After she started taking twice daily doses of SCMKT extract granules (2.5 g per dose), her muscle cramps completely disappeared, with the exception of a single instance the morning after she started SCMKT. One month after the initiation of SCMKT, and at the patient’s request, we prescribed another Kampo medicine, shimotsuto, which has previously been reported to be effective for muscle cramps. This replaced the SCMKT and allowed us to compare its effectiveness with that of SCMKT. After taking shimotsuto for 1 month, the patient reported that she had experienced strong muscle cramps with stiffness in her calves four times during the month. Case 2 was a 68-year-old female with a 10 year history of vertigo and dyspepsia. Kampo treatment, primarily with hangebyakujutsutemmato, had improved these symptoms, but a muscle cramp in her right calf had newly occurred while she was walking and then lasted for 3 months. She thus requested another Kampo medicine to treat the muscle cramp. Her medical history included hypertension, sleep apnea syndrome, and lumbar disc herniation. Her tongue was purple, with thin white fur. Her pulse was deep, and abdominal examination found moderate abdominal strength. After she started taking 4 g of SCMKT extract granules each morning, her muscle cramp disappeared almost entirely. She also reported that her walking speed had become much faster. A muscle cramp is a bothersome symptom, and there are few effective medical treatments for it in modern medicine; however, in Kampo medicine, SKT is widely prescribed in Japan to treat muscle cramps. It is effective for short periods, but an incidence of pseudoaldosteronism as high as 11.1% [1] has been observed in patients administered the full dose. Pseudoaldosteronism occurs due to the glycyrrhizin present in the Glycyrrhizae radix component of SKT. The amount of Glycyrrhizae radix in SKT is approximately three to six times higher than that in other Kampo medicines, and safer options that do not include Glycyrrhizae radix are thus necessary for the treatment of muscle cramps. SCMKT is composed of seven herbs: Angelicae radix, Paeoniae radix, Cnidii rhizoma, Rehmanniae radix, Phellodendri cortex, Astragali radix, and Uncariae uncis cum ramulus. It is usually prescribed for hypertension and related symptoms such as headache or shoulder stiffness [2]. SCMKT does not include Glycyrrhizae radix, and there is therefore no risk of pseudoaldosteronism with its use. Two Kampo medicines were recently reported to be effective for the treatment of muscle cramps: shimotsuto and sokeikakketsuto. Shimotsuto is prescribed mainly for anemia and does not include Glycyrrhizae radix. Ito et al. report that treatment with shimotsuto extract granules improved muscle cramps in 18 of 26 (69%) patients [3]. Sokeikakketsuto is effective for neuralgia or joint pain; it includes Glycyrrhizae radix but has only one-sixth of the amount in SKT. Dokura et al. report that a 4 week treatment with sokeikakketsuto extract granules improved muscle cramps in 32 of 33 (97%) patients [4]. SCMKT was apparently effective for the muscle cramps of both of the two presented patients. SCMKT is composed of Phellodendri cortex, Astragali radix, and Uncariae uncis cum ramulus, in addition to four herbs Received: 2 March 2023 Revised: 26 June 2023 Accepted: 29 June 2023