Mirtazapine for Severe Nausea and Vomiting During Pregnancy: Case Presentations and Recommendations

Severe nausea and vomiting in pregnancy (sNVP) causes numerous detrimental short-term and long-term impacts on the physical and mental health of mothers and newborns, yet treatments are limited. When first-line drugs are ineffective, minimal data on efficacy, safety, and tolerability are available for other agents. Mirtazapine is a compelling potential therapy for sNVP because it is effective in reducing nausea and vomiting in other medically ill populations, and its safety and dosing have been established because it is prescribed to pregnant women for psychiatric disorders.

We present 2 patients with sNVP. Both had not responded to standard antiemetics recommended by the American College of Obstetricians and Gynecologists (ACOG), including third-line and fourth-line agents. They were admitted to the antepartum unit and treated with mirtazapine 15 mg orally disintegrating tablets in addition to their antiemetic regimen.

The symptoms of both patients rapidly improved and were sustained over a 3-week acute treatment phase without requiring dose escalation. They were tapered off other antiemetics with continued symptom control and reported minimal distress from side effects. One patient continued mirtazapine into the maintenance phase and remained symptom-free after taper.

The outcomes from 2 carefully evaluated and tracked cases of sNVP requiring hospitalization with successful symptom resolution on mirtazapine are presented. To our knowledge, this series is the first to recommend treatment guidelines for the use of mirtazapine in the obstetric setting. We discuss how to taper and manage side effects as well as considerations for psychiatric referral. Finally, we discuss suggestions for future studies.