Clinical Epidemiology (Feb 2021)
Antiemetic Prescription Fills in Pregnancy: A Drug Utilization Study Among 762,437 Pregnancies in Norway
Abstract
Marleen MHJ van Gelder,1,2 Hedvig Nordeng3,4 1Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, the Netherlands; 2Radboud REshape Innovation Center, Radboud University Medical Center, Nijmegen, the Netherlands; 3PharmacoEpidemiology and Drug Safety Research Group, Department of Pharmacy, and PharmaTox Strategic Research Initiative, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway; 4Department of Child Health and Development, Norwegian Institute of Public Health, Oslo, NorwayCorrespondence: Marleen MHJ van GelderDepartment for Health Evidence (HP133), Radboudumc, P.O. Box 9101, Nijmegen, 6500 HB, the NetherlandsTel +31 24 3666126Fax +31 24 3613505Email [email protected]: To determine antiemetic prescription fill patterns during pregnancy in Norway, with special focus on the use of ondansetron and recurrent use in subsequent pregnancies.Methods: We conducted a population-based registry study based on data from the Medical Birth Registry of Norway linked to the Norwegian Prescription Database for 762,437 pregnancies > 12 gestational weeks ending in live or non-live births between 2005 and 2017. Prescription fills of medications used for nausea and vomiting of pregnancy were summarized in treatment pathways to determine drug utilization patterns. Logistic regression analyses were used to estimate associations between maternal and pregnancy characteristics and antiemetic prescription fills.Results: The prescription fill rate for antiemetic medication during pregnancy was 7.6%. However, prescription fill rates were 35.5% in the second pregnancy after filling an antiemetic prescription in the first pregnancy and 53.5% for women who filled antiemetic prescriptions in the previous 2 pregnancies. Among pregnancies with antiemetic prescription fills, 62.2% were dispensed metoclopramide, 28.2% meclizine, and 17.2% promethazine. First-line treatment started with monotherapy in 97.4% of these pregnancies, which was the only treatment received in 78.7%. Prescriptions for ondansetron were filled in 0.3% of pregnancies, with 76.9% being initially filled in the first trimester. Ondansetron as first-line prescription medication and/or use in the first trimester was associated with proxies for more severe nausea and vomiting of pregnancy, including a diagnosis of hyperemesis gravidarum, multiple gestations, a higher obstetric comorbidity index, and concomitant use of medication for gastroesophageal reflux disease and nervous system medications. Women who filled an antiemetic prescription in their first pregnancy were less likely to have subsequent pregnancies than women who did not fill an antiemetic prescription in their first pregnancy (OR 0.93, 95% CI 0.90– 0.96).Conclusion: Complex patterns of antiemetic prescription fills in pregnancy may mirror the challenge of optimal management of nausea and vomiting of pregnancy in clinical practice, especially for women with severe symptoms.Keywords: hyperemesis gravidarum, MBRN, metoclopramide, nausea and vomiting of pregnancy, NorPD, ondansetron
