Reviewing the evidence for using continuous subcutaneous metoclopramide and ondansetron to treat nausea & vomiting during pregnancy.

To examine the medical evidence regarding the clinical efficacy and cost-effectiveness of the application of continuous subcutaneous metoclopramide and ondansetron to treat nausea and vomiting during pregnancy. All of the published peer-reviewed articles on the subject were assembled and assigned a level of evidence based on research design. The search uncovered one level II matched, controlled trial and three level III uncontrolled, retrospective case series published in peer review journals, as well as a book chapter. The book chapter, although not subjected to the peer-review process, is included in this review due to the paucity of other evidence. The matched cohort trial showed that continuous subcutaneous metoclopramide is significantly less-tolerated than continuous subcutaneous ondansetron (31.8% vs. 4.4%; P < 0.001). The four case series reported complete symptom resolution for 63.9% to 75% of the patients. Complications arose in 24.9% to 30.5% of the selected cases that were severe enough to require discontinuation of therapy. Complications included side effects of a worsening of symptoms. All of the trials are retrospective and observational in nature and, therefore, subject to the limitations inherent in the research design. Absent the benefit of meaningful cohort controls, comparative statements effectiveness cannot be substantiated with the available data. Randomized, controlled trials of sufficient power are necessary before long-term continuous subcutaneous metoclopramide or ondansetron can be used on a widespread basis to treat nausea and vomiting during pregnancy. Cost approximations in the case series are reported and, when compared to the cost of other methods of treatment previously published in the medical literature, the therapy appears to be cost-prohibitive. However, definitive statements cannot be made regarding cost-effectiveness until clinical efficacy is demonstrated through a sufficiently powered, well-designed, randomized control trial (RCT). Until such time, the therapy should remain experimental and coverage be restricted to intractable hyperemesis gravidarum (HG) that is unresponsive to more-conventional treatment options.