We report a case of a 74-year-old male with hyponatremia complicated with small cell lung cancer. His hyponatremia worsened even with water restriction. Oral administration of sodium was difficult because of nausea and vomiting. We recognized this patient as having illness caused by excessive water accumulation within the body, and so prescribed goreisan 7.5 g/day to treat his hyponatremia. His hyponatremia improved after the administration of goreisan. Later his hyponatremia deteriorated while being administered of meloxicam, a cyclooxygenase-2 inhibitor. This case suggests that goreisan might inhibit water reabsorption by antidiuretic hormone at the collecting duct of the kidneys via stimulation of prostaglandin synthesis.

We report five cases of acute hyperventilation attack, with bilateral fullness of the chest and hypochondrium, and bilateral rectus abdominis muscle strain, that were successfully treated with shigyakusan. Case 1 was a 47-year-old female ; case 2 was an 18-year-old female ; case 3 was a 23-year-old female ; case 4 was a 39-year-old male ; and case 5 was a 40-year-old male. All five patients visited the emergency department with complaints of severe dyspnea and tetany. Their abdominal signs were characteristic, with remarkable bilateral fullness of the chest and hypochondrium and bilateral rectus abdominis muscle strain. In cases 1 to 4, the patients were given 2.5 g of shigyakusan extract, and their symptoms promptly improved. In case 5, as the patient could not swallow the prescribed medication at presentation, intramuscular diazepam was given. Thereafter, he complained of continuous severe numbness ; we subsequently gave him shigyakusan, and his numbness promptly improved. In conclusion, shigyakusan seems to be a useful Kampo drug for the treatment of acute hyperventilation attack.