Comparison of Pregnancy Outcomes of Patients Treated With Ondansetron vs Alternative Antiemetic Medications in a Multinational, Population-Based Cohort

Signal mining of adverse reactions in the antiemetic drug ondansetron during pregnancy:A Real-World analysis of the FDA adverse Event Reporting System (FAERS)

BACKGROUND

The aim of this study is to assess the risks associated with the use of ondansetron in pregnant women in real-world based on the Food and Drug Administration adverse Event Reporting System (FAERS).

METHODS

The FAERS data from the 2017Q1 to the 2023Q1, which was used by the ratio-of-reporting (ROR) and Bayesian confidence interval progressive neural network (BCPNN) to assess the safety of ondansetron in pregnancy.

RESULTS

A total of 15,727 pregnancy population reports were reported, with a total of 1,064 reports of adverse reactions with ondansetron as the primary suspected drug. Ondansetron was involved in a total of 10 system organ classifications (SOCs) of signal generation, and the top three signal intensities were Congenital, familial and genetic disorders (ROR=19.1, ROR025=17.03; IC=1.23, IC025=1.16), Ear and labyrinth disorders (ROR=17.11, ROR025=12.46; IC=1.22, IC025=1.03), and Cardiac disorders (ROR=9.48, ROR025=8.38; IC=1.12, IC025=1.03); signals of adverse reactions obtained of 216, of which the main ones were Anhedonia (IC=1.34, IC025=1.08), Injury (IC=1.34, IC025=1.19), Left-to-right cardiac shunt (IC=1.33, IC025=1.05).

CONCLUSION

The adverse reactions of Ondansetron involve multiple systems and organs, which should cause clinical vigilance. However, due to the limitations of the data, the causal relationship and risk level of adverse reactions cannot be accurately inferred.

The Management of Nausea and Vomiting in Pregnancy and Hyperemesis Gravidarum (Green-top Guideline No. 69)

An objective and validated index of nausea and vomiting such as the Pregnancy-Unique Quantification of Emesis (PUQE) and HyperEmesis Level Prediction (HELP) tools can be used to classify the severity of NVP and HG. [Grade C] Ketonuria is not an indicator of dehydration and should not be used to assess severity. [Grade A] There are safety and efficacy data for first line antiemetics such as anti (H1) histamines, phenothiazines and doxylamine/pyridoxine (Xonvea®) and they should be prescribed initially when required for NVP and HG (Appendix III). [Grade A] There is evidence that ondansetron is safe and effective. Its use as a second line antiemetic should not be discouraged if first line antiemetics are ineffective. Women can be reassured regarding a very small increase in the absolute risk of orofacial clefting with ondansetron use in the first trimester, which should be balanced with the risks of poorly managed HG. [Grade B] Metoclopramide is safe and effective and can be used alone or in combination with other antiemetics. [Grade B] Because of the risk of extrapyramidal effects metoclopramide should be used as second-line therapy. Intravenous doses should be administered by slow bolus injection over at least 3 minutes to help minimise these. [Grade C] Women should be asked about previous adverse reactions to antiemetic therapies. If adverse reactions occur, there should be prompt cessation of the medications. [GPP] Normal saline (0.9% NaCl) with additional potassium chloride in each bag, with administration guided by daily monitoring of electrolytes, is the most appropriate intravenous hydration. [Grade C] Combinations of different drugs should be used in women who do not respond to a single antiemetic. Suggested antiemetics for UK use are given in Appendix III. [GPP] Thiamine supplementation (either oral 100 mg tds or intravenous as part of vitamin B complex (Pabrinex®)) should be given to all women admitted with vomiting, or severely reduced dietary intake, especially before administration of dextrose or parenteral nutrition. [Grade D] All therapeutic measures should have been tried before considering termination of pregnancy. [Grade C].

Inpatient Management of Hyperemesis Gravidarum

Hyperemesis gravidarum has a reported incidence of approximately 0.3-3% of pregnancies. Without treatment, refractory hyperemesis gravidarum can result in dehydration, electrolyte deficiencies, and severe nutritional deficiencies, resulting in significant maternal morbidity. The overall goals of inpatient management of refractory hyperemesis gravidarum are the resumption of oral intake to an adequate level to maintain hydration and nutrition, including the ability to tolerate oral pharmacotherapy. Patients initially are stabilized with rehydration and electrolyte repletion. There are numerous pharmacotherapeutics available that can be administered intravenously to control symptoms when oral intake is not an option. However, despite maximizing typical antiemetics, there will be cases refractory to these medications, and alternative pharmacotherapeutics and nutrition-support modalities must be considered. Mirtazapine, olanzapine, corticosteroids, and gabapentin are examples of alternative pharmacotherapeutics, and enteral and parenteral nutrition are alternative therapies that can be used when oral intake is not tolerated for prolonged time periods with ongoing weight loss. In refractory cases of hyperemesis gravidarum, the risks and benefits of these alternative forms of management must be considered, along with the risks of undertreated hyperemesis gravidarum and the overall effect of hyperemesis gravidarum on patients' quality of life.

Understanding Australian Pharmacists' Perceptions on the Utilisation of Oral 5-HT3 Antagonists as Pharmacist-Only Anti-Emetics in Comparison to Oral D2 Antagonists

Objectives: To investigate the perception of community pharmacists on the down-scheduling of 5-HT3 antagonists to pharmacist-only-medicine for treatment of acute nausea and/or vomiting in Australia. Methods: A nationwide anonymous survey targeting Australian community pharmacists was conducted from April to May 2023. Responses were collected and analysed quantitively or qualitatively, where appropriate. Key findings: Participants reported that 5-HT3 antagonists were effective at treating nausea and/or vomiting and would likely recommend their use. Training is required to manage supply due to concerns related to their side effects. Conclusion: Participants supported down-scheduling of 5-HT3 antagonists for the treatment of nausea and/or vomiting in Australia. A pilot study on the provision of 5-HT3 antagonists by pharmacists is recommended as is the development of guidelines for pharmacist-only supply before down-scheduling is considered.

Embryo-fetal safety evaluation of ondansetron in rats

BACKGROUND

Ondansetron is a 5HT3 receptor antagonist, used to mitigate the effects of nausea and vomiting after chemotherapy or surgery. Since nausea and vomiting are common experiences during the first trimester of pregnancy, this antiemetic has been the main drug used during this period.

METHODS

To evaluate the effects of ondansetron on the embryo-fetal development, which are still very contradictory, pregnant rats were exposed to therapeutic doses of ondansetron (1.7 or 2.5 mg/kg) daily, from gestational day (GD) 6 to 15.

RESULTS

No clinical signs of toxicity were observed in dams during the treatment. Although the hemato-biochemical parameters were similar among the groups, histological changes, as well as a reduction in the weight of kidney were found in the treated dams. After fetal examination, no visceral and skeletal abnormalities were observed in treated fetuses.

CONCLUSION

In conclusion, therapeutic doses of ondansetron have low teratogenic potential in rats. These data provide important information about the drug safety during pregnancy.

Clinical advances: pregnancy in gastroenterologic and hepatic conditions

The fields of gastroenterology and hepatology, along with endoscopic practice, have seen significant changes and innovations to practice in just the past few years. These practice changes are not limited to gastroenterology, but maternal fetal medicine and the care of the pregnant person have become increasingly more sophisticated as well. Gastroenterologists are frequently called on to provide consultative input and/or perform endoscopy during pregnancy. To be able to provide the best possible care to these patients, gastroenterologists need to be aware of (and familiar with) the various nuances and caveats related to the care of pregnant patients who either have underlying gastrointestinal (GI) conditions or present with GI and liver disorders. Here, we offer a clinical update with references more recent than 2018, along with a few words about SARS-CoV-2 infection and its relevance to pregnancy.

Patterns of antiemetic medication use during pregnancy: A multi-country retrospective cohort study

OBJECTIVE

To compare patterns in use of different antiemetics during pregnancy in Canada, the United Kingdom, and the United States, between 2002 and 2014.

METHODS

We constructed population-based cohorts of pregnant women using administrative healthcare data from five Canadian provinces (Alberta, British Columbia, Manitoba, Ontario, and Saskatchewan), the Clinical Practice Research Datalink from the United Kingdom, and the IBM MarketScan Research Databases from the United States. We included pregnancies ending in live births, stillbirth, spontaneous abortion, or induced abortion. We determined maternal use of antiemetics from pharmacy claims in Canada and the United States and from prescriptions in the United Kingdom.

RESULTS

The most common outcome of 3 848 734 included pregnancies (started 2002-2014) was live birth (66.7% of all pregnancies) followed by spontaneous abortion (20.2%). Use of antiemetics during pregnancy increased over time in all three countries. Canada had the highest prevalence of use of prescription antiemetics during pregnancy (17.7% of pregnancies overall, 13.2% of pregnancies in 2002, and 18.9% in 2014), followed by the United States (14.0% overall, 8.9% in 2007, and 18.1% in 2014), and the United Kingdom (5.0% overall, 4.2% in 2002, and 6.5% in 2014). Besides use of antiemetic drugs being considerably lower in the United Kingdom, the increase in its use over time was more modest. The most commonly used antiemetic was combination doxylamine/pyridoxine in Canada (95.2% of pregnancies treated with antiemetics), ondansetron in the United States (72.2%), and prochlorperazine in the United Kingdom (63.5%).

CONCLUSIONS

In this large cohort study, we observed an overall increase in antiemetic use during pregnancy, and patterns of use varied across jurisdictions. Continued monitoring of antiemetic use and further research are warranted to better understand the reasons for differences in use of these medications and to assess their benefit-risk profile in this population.

[Expert consensus from the College of French Gynecologists and Obstetricians: Management of nausea and vomiting of pregnancy and hyperemesis gravidarum]

OBJECTIVE

To determine the management of patients with 1st trimester nausea and vomiting and hyperemesis gravidarum.

METHODS

A panel of experts participated in a formal consensus process, including focus groups and two Delphi rounds.

RESULTS

Hyperemesis gravidarum is distinguished from nausea and vomiting during pregnancy by weight loss≥5 % or signs of dehydration or a PUQE score≥7. Hospitalization is proposed when there is, at least, one of the following criteria: weight loss≥10%, one or more clinical signs of dehydration, PUQE (Pregnancy Unique Quantification of Emesis and nausea) score≥13, hypokalemia<3.0mmol/L, hyponatremia<120mmol/L, elevated serum creatinine>100μmol/L or resistance to treatment. Prenatal vitamins and iron supplementation should be stopped without stopping folic acid supplementation. Diet and lifestyle should be adjusted according to symptoms. Aromatherapy is not to be used. If the PUQE score is<6, even in the absence of proof of their benefit, ginger, pyridoxine (B6 vitamin), acupuncture or electrostimulation can be used, even in the absence of proof of benefit. It is proposed that drugs or combinations of drugs associated with the least severe and least frequent side effects should always be chosen for uses in 1st, 2nd or 3rd intention, taking into account the absence of superiority of a class over another to reduce the symptoms of nausea and vomiting of pregnancy and hypermesis gravidarum. To prevent Gayet Wernicke encephalopathy, Vitamin B1 must systematically be administered for hyperemesis gravidarum needing parenteral rehydration. Patients hospitalized for hyperemesis gravidarum should not be placed in isolation (put in the dark, confiscation of the mobile phone or ban on visits, etc.). Psychological support should be offered to all patients with hyperemesis gravidarum as well as information on patient' associations involved in supporting these women and their families. When returning home after hospitalization, care will be organized around a referring doctor.

CONCLUSION

This work should contribute to improving the care of women with hyperemesis gravidarum. However, given the paucity in number and quality of the literature, researchers must invest in the field of nausea and vomiting in pregnancy, and HG to identify strategies to improve the quality of life of women with nausea and vomiting in pregnancy or hyperemesis gravidarum.

Risk of abnormal pregnancy outcomes after using ondansetron during pregnancy: A systematic review and meta-analysis

Background: Hyperemesis gravidarum is a serious pregnancy complication that affects approximately 1% of pregnancies worldwide.

Objective: To determine whether the use of ondansetron during pregnancy is associated with abnormal pregnancy outcomes.

Search strategy: PubMed, Cochrane Library, CINAHL, Embase, CNKI, CBM, WANFANG, and ClinicalTrials.gov were searched for citations published in any language from inception to 15 December 2021.

Selection criteria: Eligible studies included any observational study.

Data collection and analysis: Odds ratio (OR) and 95% confidence interval (CI) were used as indicators to examine the association between ondansetron and abnormal pregnancy outcomes.

Main results: Twenty articles from 1,558 citations were included. Our preliminary analysis showed that compared with the unexposed group, the use of ondansetron during pregnancy may be associated with an increased incidence of cardiac defects (OR = 1.06, 95% CI: 1.01–1.10), neural tube defects (OR = 1.12, 95% CI: 1.05–1.18), and chest cleft (OR = 1.21, 95% CI: 1.07–1.37). Further sensitivity analysis showed no significant association between ondansetron and cardiac defects (OR = 1.15,95% CI: 0.94–1.40) or neural tube defects (OR = 0.87,95% CI: 0.46–1.66). When controversial studies were eliminated, the results for the chest defects disappeared. Simultaneously, we found that the use of ondansetron was associated with a reduced incidence of miscarriage (OR = 0.53, 95% CI: 0.31–0.89). Ondansetron was not associated with orofacial clefts (OR = 1.09,95% CI: 0.95–1.25), spinal limb defects (OR = 1.14,95% CI: 0.89–1.46), urinary tract deformities (OR = 1.06,95% CI: 0.97–1.15), any congenital malformations (OR = 1.03,95% CI: 0.98–1.09), stillbirth (OR = 0.97,95% CI: 0.83–1.15), preterm birth (OR = 1.22,95% CI: 0.80–1.85), neonatal asphyxia (OR = 1.05,95% CI: 0.72–1.54), or neonatal development (OR = 1.18,95% CI: 0.96–1.44) in our primary analysis.

Conclusion: In our analysis, using ondansetron during pregnancy was not associated with abnormal pregnancy outcomes. Although our study did not find sufficient evidence of ondansetron and adverse pregnancy outcomes, future studies including the exposure period and dose of ondansetron, as well as controlling for disease status, may be useful to truly elucidate the potential risks and benefits of ondansetron.

Ondansetron versus metoclopramide for managing hyperemesis gravidarum: A systematic review and meta-analysis of randomized controlled trials

This investigation examined the efficacy of ondansetron (intervention) versus metoclopramide (control) in managing parturient females with hyperemesis gravidarum (HG), by pooling data from randomized controlled trials (RCTs) using a meta-analysis approach. From inception until January 2022, five information sources were screened: Cochrane Central Register of Controlled Trials, Google Scholar, Scopus, PubMed and Web of Science. Quality assessment was done through the Cochrane Risk of Bias (version 2) assessment tool. The mean difference (MD) with 95% confidence interval (CI) was used to summarize the continuous data in a fixed- or random-effects model, depending on the extent of between-study heterogeneity. Five RCTs were included, comprising a total of 695 patients (355 and 340 females were assigned to ondansetron and metoclopramide, respectively). Four RCTs had an overall “low” risk of bias, whereas one RCT had an overall “some concerns” due to lack of sufficient information about randomization. There was no significant difference between both groups regarding the pregnancy-unique quantification of emesis and nausea score [MD=0.23, 95% CI (-0.42, 0.88), p=0.49], length of hospital stay [MD=-0.17 days, 95% CI (-0.35, 0.02), p=0.08], the number of doses of drug received [MD=0.45, 95% CI (-0.08, 0.98), p=0.10], and duration of intravenous fluids [MD=-1.73 hours, 95% CI (-5.79, 2.33), p=0.40]. Among parturient females with HG, there was no substantial difference in efficacy between both agents. Nevertheless, ondansetron is favored over metoclopramide in view of its trending therapeutic efficacy and better safety profile.

Ondansetron use in nausea and vomiting during pregnancy: a descriptive analysis of prescription patterns and patient characteristics in UK general practice

Aims

The objective of this study was to describe ondansetron drug utilization patterns during pregnancy to treat nausea and vomiting in pregnancy (NVP). Moreover, we aimed to describe the maternal factors associated with NVP and antiemetic use.

Methods

The data consist of pregnancies with a live birth(s) within an IMRD‐UK registered GP practice. Descriptive statistics were used to investigate patterns of ondansetron use in pregnancy and to describe maternal characteristics associated with NVP and antiemetic drug utilization. We differentiate first‐ from second‐line use during pregnancy using antiemetic prescription pathways.

Results

The dataset included 733 633 recorded complete pregnancies from 2005 to 2019. NVP diagnosis and ondansetron prescription prevalence increased from 2.7% and 0.1% in 2005 to 4.8% and 2.5% in 2019 respectively. Over the period 2015–2019, the most common oral daily dosages were 4 mg/d (8.5%), 8 mg/d (37.1%), 12 mg/d (37.5%) and between 16 and 24 mg/d (16.9%). Prescription of ondansetron was initiated during the first trimester of pregnancy in 40% of the cases and was moderately used as a first‐line therapy (2.8%), but preferred choice of second‐line therapy. Women with mental health disorders, asthma and/or prescribed folic acid were more likely to experience NVP and use antiemetics in pregnancy than their counterparts.

Conclusion

This study confirms that ondansetron is increasingly used off‐label to treat NVP during pregnancy, also in the first trimester and before other prescription antiemetics have been prescribed. Several maternal comorbidities and folic acid use were more common among women experiencing NVP and using antiemetics, including ondansetron.

Hyperemesis gravidarum in the primary care setting: cross-sectional study of GPs

BACKGROUND

Hyperemesis gravidarum (HG), if untreated, can lead to malnutrition, dehydration, and Wernicke's encephalopathy. Foetal complications include low birth weight and neurodevelopmental delay. Recent evidence supports increased rates of termination of pregnancy and suicidal ideation. Drivers included difficulty in accessing medications, which thus contributed to poor perception of care.

AIM

To identify factors that may influence prescribers' confidence and knowledge regarding pharmacological therapy for HG.

DESIGN & SETTING

Cross-sectional study of qualified GPs and GP trainees in Wales.

METHOD

Distribution of a 22-item online survey. Statistical analysis was carried out using SPSS.

RESULTS

In total, 241 responses were received, with 216 included in the analysis (59% qualified GPs, 41% GP trainees). In total, 93% of responders correctly identified cyclizine as being safe in pregnancy, but no other drug recommended in the Royal College of Obstetrics and Gynaecology guidance was considered safe by more than 58%. Those reporting higher confidence levels in managing HG were more likely to correctly report guideline-recommended drugs as safe in pregnancy (P = 0.04). Additional qualifications related to obstetrics and gynaecology (O&G) and/or prior clinical experience increased confidence levels (P = 0.0001 and P = 0.0002, respectively). Only 19% of participants routinely screened for signs of mental health complications, and prior experience or education did not increase likelihood of this happening. The majority of participants (87%) would like additional education and/or access to evidence-based resources.

CONCLUSION

This study demonstrates a demand for improved dissemination of evidence-based education on HG to support those working in primary care. The extent to which HG is covered in pre-existing educational programmes should also be revisited.

[Nausea and vomiting in pregnancy: A place for ondansetron?]

Although there is no recommendation in France relating to the treatment of nausea and vomiting of pregnancy, there are some in other countries, where ondansetron, widely used, appears to be an effective second-line treatment option behind doxylamine/vitamin B6 association and metoclopramide. However, based on some recent publication suggesting an increased risk of orofacial clefts and congenital heart defects in fetuses exposed in utero to ondansetron in the 1st trimester of pregnancy, the European Medicines Agency now states that this drug should not longer be used during this period. This 2019 decision is controversial and whether ondansetron can be used in pregnant women with severe vomiting during pregnancy is still in question.

Termination of wanted pregnancy and suicidal ideation in hyperemesis gravidarum: A mixed methods study

Background

Difficulty accessing medication and poor patient experience have been implicated as risk factors for termination of pregnancy and suicidal ideation in women with hyperemesis gravidarum. We aimed to gain further insight into these factors in order to further inform and improve patient care.

Methods

We performed a sub-analysis on quantitative data generated through a UK-wide survey of 5071 participants. A qualitative analysis of free text comments was performed using an inductive thematic approach.

Results

41.2% % of women taking prescribed medications had to actively request them. ‘Extremely poor’ or ‘poor’ experiences were described in 39.4% and 30.0% of participants in primary and secondary care respectively. Protective factors for termination of pregnancy and suicidal ideation include holistic support from family, friends and healthcare providers.

Conclusion

Optimal care in hyperemesis gravidarum should incorporate timely access to pharmacotherapy, assessment of mental health, consideration of referral to specialist services and care being delivered in a compassionate manner.