[Effectiveness of mirtazapine for digestive symptoms in palliative care - retrospective study of 50 cases].

Background: Previous research has reported that mirtazapine, a 5-HT3 antagonist, is effective for alleviation of digestive symptoms.

Purpose: To elucidate the effect of low-dose mirtazapine on digestive symptoms.

Patients And Methods: Mirtazapine was administered to 50 cancer patients with digestive symptoms in palliative care, and the data were retrospectively examined. The initial doses ranged from 1.875 to 7.5 mg, and were increased to a maintenance dose according to its effects and the degree of somnolence.

Results: The cases were divided into 2 groups based on the cause of the digestive symptoms, including unknown causes(27 cases)and chemotherapy and/or opioid treatment(23 cases). At the initial dose, the efficacy rate was 74.4%, and the effectiveness was significantly higher in patients whose symptoms were due to chemotherapy and/ or opioid use than in those with symptoms of unknown cause(p=0.008). The rate of somnolence was 29.5%. Discontinuation of treatment within 1 week occurred in 10 cases. In 40 cases that continued administration of the maintenance dose, the efficacy rate was 82.5%, and the increased doses provided relief in the patient group with digestive symptoms of unknown cause.

Conclusions: Low-dose mirtazapine showed different effects depending on the cause of digestive symptoms; therefore, the dose should be increased in patients whose symptoms are of unknown cause. Somnolence often appeared even at a low-dose, and this should be taken into consideration in the palliative care setting.