The delayed-release combination of doxylamine and pyridoxine (Diclegis®/Diclectin ®) for the treatment of nausea and vomiting of pregnancy

[Hyperemesis Gravidarum - an Interprofessional and Interdisciplinary Challenge - Evidence-Based Review]

Hyperemesis gravidarum (HG) is a multifactorial disease characterized by severe and persisting nausea and vomiting, impairment of oral intake, weight loss of at least 5%, electrolyte abnormalities, and dehydration. The prevalence of HG ranges from 0.3 to 10% worldwide. The diagnosis is made by the patient's prehistory, clinical symptoms, physical examination, and the typical laboratory abnormalities. Therapeutic cornerstones are nutrition advice, consultation of life style, psychological/psychosocial support of the mother as well as the administration of antiemetics in a stepwise approach, depending on the severity of symptoms, and finally admission to hospital in severe cases. Treatment of patients requires close interprofessional and interdisciplinary cooperation.

Prevalence and burden of nausea and vomiting in pregnant women: Interim analysis of the PURITY survey

OBJECTIVES

Nausea and vomiting in pregnancy is a common and invalidating condition in early pregnancy. However, no data are available on its prevalence in Italy. This survey aims to evaluate the prevalence and impact of nausea and vomiting during pregnancy on the quality of life of Italian women.

STUDY DESIGN

The survey was performed in three Italian public University Hospitals in two distinct periods: a first interview took place between the 18th and 22nd week of pregnancy, using the Questionnaire for Pregnancy Period (14 questions regarding demographic data and 30 questions about nausea and vomiting in pregnancy, including Pregnancy-Unique Quantification of Emesis questionnaire), and a follow-up interview, by telephone call, took place immediately after giving birth and in any case within 14 days of delivery, using the Questionnaire for Post-Pregnancy (9 questions). Included women were Caucasian, in physiological pregnancy and between the 18th and 22nd week (time of morphological ultrasound), able to communicate adequately with the interviewer, understand the questionnaires and able to provide valid informed consent. Twin pregnancies and women who recurred to medically assisted procreation were excluded. This is an interim report on data collected from 232 of the planned 600 women.

RESULTS

Mean age of the recruited subjects was 32.6 ± 4.6 years, with approximately 60% primiparous. The prevalence of nausea and vomiting in pregnancy in the sample examined was 65.5% overall (152 out of 232 subjects). Of these 152 women, 63 (41.4%) experienced only nausea, 6 (3.9%) only vomiting, and 83 (54.6%) reported both. Symptoms were reported to begin at 7.2 ± 2.7 weeks, lasted 10.2 ± 5.6 weeks, and persisted at the time of the interview in 32.2% of cases. Overall, over 50% of the women interviewed experienced a negative impact of nausea and vomiting in pregnancy on social relationships and work activity.

CONCLUSIONS

A high prevalence of nausea and vomiting in pregnancy, 65.5% overall, was found in this interim analysis. These symptoms appeared capable of negatively influencing women quality of life. Screening procedures should be offered during pregnancy and measures that address nausea and vomiting in pregnancy impact warranted.

The effects of pyridoxine (vitamin B6) supplementation in nausea and vomiting during pregnancy: a systematic review and meta-analysis

PURPOSE

Nausea and vomiting during pregnancy (NVP) are common symptoms in pregnancy. Although no definitive treatment option for NVP, pyridoxine (Vitamin B6) supplementation has been used widely. The present study aims to systematically evaluate the current evidence regarding pyridoxine for the treatment of NVP.

METHODS

Data were obtained using a stepwise search process using keywords in the following online medical databases; PubMed®, Web of Science®, and Scopus® for studies published before 1st May 2021. Studies reporting intervention with pyridoxine supplementation alone and/or with other active substances were included. A meta-analysis was performed on the PUQE score and Rhode's score for nausea and vomiting.

FINDINGS

Initial database searching indicated 548 potentially eligible articles, of which 18 studies satisfying the inclusion criteria were selected. Eight studies showed beneficial effects with pyridoxine alone as the supplementation, while six others found that the supplementation of pyridoxine in combination with another active substance had favourable effects. Supplementation of pyridoxine alone as well as combined treatment of pyridoxine with an active ingredient as the intervention significantly improved the symptoms of nausea according to Rhode's score [0.78 [95% CI: 0.26, 1.31; p = 0.003; I2 = 57%, p = 0.10)] and PUQE score [0.75 (95% CI: 0.28, 1.22; p = 0.002; I2 = 0%, p = 0.51)], respectively.

CONCLUSION

Supplementation of pyridoxine alone as well as with an active ingredient demonstrated beneficial effects for women suffering from NVP.

Bioavailability of Cariban® Capsules: A Modified-Release Fixed-Dose Combination of Doxylamine and Pyridoxine to Relieve Nausea and Vomiting During Pregnancy

BACKGROUND

Nausea and vomiting is a very prevalent condition during pregnancy. Combination of doxylamine and pyridoxine is placed as first-line pharmacological option for its treatment in most clinical guidelines. Among different release forms available, Cariban^® is a fixed-dose combination of doxylamine/pyridoxine 10/10 mg, formulated as modified-release capsules.

OBJECTIVES

In the present study, we aimed to characterize the bioavailability performance of Cariban^® in vitro and in vivo.

METHODS

An in vitro dissolution test was performed to evaluate the release profile of Cariban^®, together with immediate- and delayed-release formulations available on the market. A single-center, single-dose, open-label bioavailability study following Cariban^® administration in 12 healthy adult female patients was carried out to explore the drug behavior in vivo (protocol NBR-002-13; EUDRA-CT 2013-005422-35). These data were additionally used to perform a computational pharmacokinetic simulation of the posology approved for this drug.

RESULTS

Cariban^® capsules demonstrate a prolonged-release performance, with an early, gradual, and progressive release of both actives until reaching a complete dissolution after 4-5 h in solution. The pharmacokinetic features of these capsules show that doxylamine and pyridoxine metabolites are early absorbed, being all detectable in plasma within 1 h following oral administration. Computational pharmacokinetic simulation predicts that different posology provides distinct profiles of metabolites in plasma, with 1-1-2 (morning-midafternoon-night) being the one that concentrates higher plasma levels but lower dose dumping for 24 h.

CONCLUSION

Cariban^® behaves as a prolonged-release formulation, which correlates with rapid absorption and arising of the actives in the plasma, but also long-lasting and sustained bioavailability, especially when administered following the complete posology. These results would underlie its demonstrated efficacy to relieve nausea and vomiting of pregnancy (NVP) under clinical settings.

MOLECULAR MECHANISMS UNDERLYING THERAPEUTIC ACTION OF VITAMIN B6

The aim of the study was to analyze the molecular mechanisms that determine the possibility of using vitamin B6 in clinical practice for the correction of various pathological conditions.

Materials and methods. Information retrieval (Scopus, PubMed) and library (eLibrary) databases were used as research tools. In some cases, the ResearchGate application was used for a semantic search. The analysis and generalization of the scientific literature on the topic of research, covering the period from 1989 to the present, has been carried out in the work.

Results. It has been shown that all chemical forms of vitamin B6 are able to penetrate the membranes of most cells by free diffusion, while forming phosphorylated forms inside. Pyridoxal phosphate is a biologically important metabolite that is directly involved as a cofactor in a variety of intracellular reactions. Requirements for this cofactor depend on the age, sex and condition of the patient. Pregnancy and lactation play a special role in the consumption of vitamin B6. In most cases, a balanced diet will provide an acceptable level of this vitamin. At the same time, its deficiency leads to the development of a number of pathological conditions, including neurodegenerative diseases, inflammations and diabetes. Negative manifestations from the central nervous system are also possible with an excessive consumption of B6.

Conclusion. Replenishment of the vitamin B6 level in case of its identified deficiency is a necessary condition for the successful treatment of the central nervous system diseases, diabetes and correction of patients’ immune status. At the same time, it is necessary to observe a balanced intake of this cofactor in order to avoid negative effects on metabolism in case of its excess.

Gastroparesis in pregnancy

Gastroparesis is a functional gastrointestinal disorder that more commonly affects women, with most cases being diagnosed during childbearing age. However, there is a paucity of data and guidelines to specifically highlight the epidemiology, disease course, maternal and fetal impact, and the management of existing gastroparesis during pregnancy. Apart from metoclopramide, there is no approved therapy specifically indicated for gastroparesis. More importantly, pregnant and breastfeeding women are excluded from clinical trials evaluating pharmacologic agents in the management of gastroparesis. This poses a real challenge to healthcare providers in counseling and managing patients with gastroparesis. In this systematic review, we summarize the current available literature and the knowledge gaps in the impact of pregnancy on gastroparesis and vice versa. We also highlight the efficacy and safety profiles of available pharmacologic and nonpharmacologic therapies in the management of patients with gastroparesis, with emphasis on judicious use of dietary approaches that are deemed relatively safe during pregnancy.

A simple and sensitive LC-MS/MS method for determination of doxylamine in human plasma and its application in a bioequivalence study in healthy Chinese volunteers

A simple, rapid, sensitive and specific LC-MS/MS method was developed and validated for the quantitative determination of doxylamine in human plasma, using isotope doxylamine-d5 as internal standard (IS). The detection was conducted on a QTRAP 5500 tandem mass spectrometer coupled with electrospray ionization (ESI) source in positive ion mode. Quantification was achieved by positive electrospray ionization containing multiple reaction monitoring (MRM) transitions of m/z 271.0→182.0 for doxylamine and m/z 276.2→187.3 for IS. The mobile phase A was methanol, and mobile phase B was 20 mM ammonium acetate (0.2 % formic acid) in water, using a gradient elution procedure at a flow rate of 0.6 mL/min. The method was validated with a sensitivity of 0.500 ng/mL and a linear concentration range of 0.500-200 ng/mL. The inter-batch precision (%CV) was less than 5.4 %, and the accuracy deviation (%RE) ranged from - 10.6 % to 3.7 %; the inter-batch precision (%CV) was less than 6.6 %, and the accuracy deviation (%RE) was ranged from - 2.7 % to 0.1 %. The selectivity, sensitivity, extraction recovery, matrix effect, carryover, dilution reliability, stability and other characteristics were within the acceptable range. This validated method was successfully applied to a bioequivalence study that orally administered 25 mg of doxylamine succinate tablets in 60 healthy Chinese volunteers.

[Interest of vitamin b6 for treatment of nausea and/or vomiting during pregnancy]

In France there is no official recommendation for the drug management of nausea and vomiting during pregnancy. In the USA, Canada and Australia, vitamin B6 is officially recommended in the treatment of mild to moderate pregnancy sickness and vomiting. Indeed, some studies have shown some effectiveness of oral vitamin B6, most often in combination with doxylamine, in comparison with a placebo. In addition, the harmlessness of oral vitamin B6 during pregnancy has been established for doses up to 40-60mg/day, mainly in combination with doxylamine (40mg/40mg). Thus, in France, as in other countries, vitamin B6 could be integrated into the therapeutic arsenal of mild to moderate nausea and vomiting during pregnancy according to the following dosage schedule: oral intake of 10mg four times a day of a compounded preparation of vitamin B6, alone or in combination with doxylamine.

The Management of Nausea and Vomiting of Pregnancy: Synthesis of National Guidelines

Importance

Nausea and vomiting of pregnancy (NVP) affects a high proportion of the pregnant population.

Objective

The aim of this study was to compare and synthesize recommendations from national guidelines regarding the management of NVP.

Evidence Acquisition

A descriptive review of 3 recently published national guidelines on NVP was conducted: Royal College of Obstetricians and Gynaecologists on "The Management of Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum," American College of Obstetricians and Gynecologists on "Nausea and Vomiting of Pregnancy," and Society of Obstetricians and Gynaecologists of Canada on "The Management of Nausea and Vomiting of Pregnancy." These guidelines were summarized and compared in terms of the recommended management of pregnant women. The quality of evidence was also reviewed based on the method of reporting.

Results

Several differences were identified on the different guidelines regarding the management of NVP. Frequent small meals and avoidance of iron supplements are recommended for prevention. The consumption of ginger, acustimulations, antihistamines, phenothiazines, dopamine, and serotonin 5-hydroxytryptamine type 3 receptor antagonists is routinely recommended for use in the community as treatment.

Conclusions

Evidence-based medicine may lead to the adoption of an international guideline for the management of NVP, which may lead to a more effective management of that entity.

The safety of early pregnancy exposure to granisetron

OBJECTIVE

Current guidelines suggest that granisetron is an optional treatment for nausea and vomiting in pregnancy (NVP) despite lack of evidence to support fetal safety. We aimed to determine the association between early pregnancy exposure to granisetron and fetal/neonatal outcomes.

DESIGN

Medical records of patients treated for NVP during the first and second trimester between June 2013 to September 2015 were reviewed. Patients were asked to participate in the study by answering a detailed questionnaire regarding newborn's health and complementary data. Pregnancy outcomes of patients exposed to granisetron were compared with those of patients who were not exposed to granisetron.

RESULTS

100 Granisetron exposed pregnancies were compared with 108 granisetron unexposed pregnancies. Exposure to granisetron occurred in the first trimester in 88 patients (94 fetuses). Maternal characteristics, history of anomalies in first degree relatives, co-exposure to other substances and extent of prenatal sonographic surveillance were comparable between both groups. Miscarriage rate was significantly lower among granisetron exposed patients compared to controls (0 vs 5.5 %, respectively, p = 0.03). Three major malformations were identified prenatally or postnatally in each of the groups (2.77 % Vs 2.83 %, p = 1). The rate of major malformations was similar between exposed and unexposed fetuses even after excluding second trimester exposure (3.2 % vs. 2.83 %, respectively p = 1). Mean gestational age at delivery, mean newborn weight and incidence of small for gestation age, were not significantly different between the groups.

CONCLUSION

Granisetron exposure was not associated with increased risk for minor or major fetal anomalies. This study provides preliminary reassurance regarding the safety of in-utero exposure to granisetron.

ACOG Practice Bulletin No. 189: Nausea And Vomiting Of Pregnancy

Nausea and vomiting of pregnancy is a common condition that affects the health of a pregnant woman and her fetus. It can diminish a woman's quality of life and also significantly contributes to health care costs and time lost from work (1, 2). Because morning sickness is common in early pregnancy, the presence of nausea and vomiting of pregnancy may be minimized by obstetricians, other obstetric care providers, and pregnant women and, thus, undertreated (1). Furthermore, some women do not seek treatment because of concerns about the safety of medications (3). Once nausea and vomiting of pregnancy progresses, it can become more difficult to control symptoms. Treatment in the early stages may prevent more serious complications, including hospitalization (4). Safe and effective treatments are available for more severe cases, and mild cases of nausea and vomiting of pregnancy may be resolved with lifestyle and dietary changes. The woman's perception of the severity of her symptoms plays a critical role in the decision of whether, when, and how to treat nausea and vomiting of pregnancy. Nausea and vomiting of pregnancy should be distinguished from nausea and vomiting related to other causes. The purpose of this document is to review the best available evidence about the diagnosis and management of nausea and vomiting of pregnancy.

Hyperemesis Gravidarum: A Review of Recent Literature

BACKGROUND

In the United States, hyperemesis gravidarum is the most common cause of hospitalization during the first half of pregnancy and is second only to preterm labor for hospitalizations in pregnancy overall. In approximately 0.3-3% of pregnancies, hyperemesis gravidarum is prevalent and this percentage varies on account of different diagnostic criteria and ethnic variation in study populations. Despite extensive research in this field, the mechanism of the disease is largely unknown. Although cases of mortality are rare, hyperemesis gravidarum has been associated with both maternal and fetal morbidity. The current mainstay of treatment relies heavily on supportive measures until improvement of symptoms as part of the natural course of hyperemesis gravidarum, which occurs with progression of gestational age. However, studies have reported that severe, refractory disease manifestations have led to serious adverse outcomes and to termination of pregnancies.

SUMMARY

Despite extensive research in the field, the pathogenesis of hyperemesis gravidarum remains unknown. Recent literature points to a genetic predisposition in addition to previously studied factors such as infectious, psychiatric, and hormonal contributions. Maternal morbidity is common and includes psychological effects, financial burden, clinical complications from nutritional deficiencies, gastrointestinal trauma, and in rare cases, neurological damage. The effect of hyperemesis gravidarum on neonatal health is still debated in literature with conflicting results regarding outcomes of birth weight and prematurity. Available therapy options remain largely unchanged in the past several decades and focus on parenteral antiemetic medications, electrolyte repletion, and nutritional support. Most studies of therapeutic options do not consist of randomized control studies and cross-study analysis is difficult due to considerable variation of diagnostic criteria. Key Messages: Hyperemesis gravidarum carries a significant burden on maternal health and US health care. Most published research on pathogenesis is observational and suggests multifactorial associations with hyperemesis gravidarum. Precise, strictly defined criteria for clinical diagnosis are likely to benefit meta-analyses of further research studies regarding pathogenesis as well as therapeutic options.

Suboptimal maternal and cord plasma pyridoxal 5' phosphate concentrations are uncommon in a cohort of Canadian pregnant women and newborn infants

Vitamin B₆ is important in fetal development, but little is known of the vitamin B₆ status of pregnant women and newborns in North America and potential modifying factors. This prospective study determined maternal and cord plasma concentrations of pyridoxal 5' phosphate (PLP; an indicator of vitamin B₆ status) in a convenience sample of 368 Canadian pregnant women and their newborns. The association of maternal intake of vitamin B₆ and fetal genetic variants with cord plasma PLP and homocysteine concentrations was also examined. Dietary and supplemental intakes of vitamin B₆ were assessed in early and mid to late pregnancy. PLP concentrations were measured in maternal plasma in early pregnancy and at delivery, and in cord plasma. Six fetal variants of the MTHFR and CβS genes were assessed for their association with cord plasma PLP and homocysteine concentrations. Geometric mean (95% CI) PLP concentrations were 107 (98, 116) nmol/L in early pregnancy and 58 (53, 62) nmol/L at delivery, respectively, and 296 (275, 319) nmol/L in cord blood (p < .0001). During early pregnancy and at delivery, 3.6% and 5.5% of women had plasma PLP concentrations <20 nmol/L, respectively. Ninety eight percent of the women with supplemental B₆ intake of at least the recommended dietary allowance had PLP concentrations >20 nmol/L. Fetal genetic variants were not associated with cord PLP and homocysteine concentrations. Vitamin B₆ deficiency is uncommon in a cohort of Canadian pregnant women due largely to prevalent vitamin B₆ supplement use.

8-Way Randomized Controlled Trial of Doxylamine, Pyridoxine and Dicyclomine for Nausea and Vomiting during Pregnancy: Restoration of Unpublished Information

Objectives

We report information about an unpublished 1970s study (“8-way” Bendectin Study) that aimed to evaluate the relative therapeutic efficacy of doxylamine, pyridoxine, and dicyclomine in the management of nausea and vomiting during pregnancy. We are publishing the trial's findings according to the restoring invisible and abandoned trials (RIAT) initiative because the trial was never published.

Design

Double blinded, multi-centred, randomized placebo-controlled study.

Setting

14 clinics in the United States.

Participants

2308 patients in the first 12 weeks of pregnancy with complaints of nausea or vomiting were enrolled.

Interventions

Each patient was randomized to one of eight arms: placebo, doxylamine/pyridoxine/dicylcomine, doxylamine/pyridoxine, dicylomine/pyridoxine, doxylamine, dicyclomine/pyridoxine, pyridoxine and dicyclomine. Each patient was instructed to take 2 tablets at bedtime and 1 additional tablet in the afternoon or morning if needed, for 7 nights.

Outcomes

Reported outcomes included the number of hours of nausea reported by patients, the frequency of vomiting reported by patients and the overall efficacy of medication as judged by physicians.

Results

Data from 1599 (69% of those randomized) participants were analyzed. Based on the available summary data of physician evaluation of symptoms and ignoring missing data and data integrity issues, the proportion of participants who were “evaluated moderate or excellent” was greater in each of the seven active treatment groups when compared with placebo (57%): doxylamine/pyridoxine/dicylcomine (14% absolute difference versus placebo; 95% CI: 4 to 24), doxylamine/pyridoxine (21; 95% CI 11 to 30), dicylomine/pyridoxine (21; 95% CI 11 to 30), doxylamine (20; 95% CI 10 to 29), dicyclomine/pyridoxine (4; 95% CI -6 to 14), pyridoxine (9; 95% CI -1 to 19) and dicyclomine (4; 95% CI -6 to 14). Based on incomplete information, the most common adverse events were apparently drowsiness and fatigue. There is a high risk of bias in these previously unpublished results given the high attrition rate in a 7 day trial, the lack of prespecified outcomes or analyses, and the exclusion of some data because of questionable data integrity.

Conclusion

The available information about this “8-way Bendectin” trial indicates it should not be used to support the efficacy of doxylamine, pyridoxine or dicyclomine for the treatment of nausea and vomiting during pregnancy because of a high risk of bias.

Trial registration

Not registered.

Nausea and vomiting of pregnancy - What's new?

Nausea and vomiting of pregnancy (NVP) is one of the most common disorders of pregnancy. The symptoms occur predominantly during the first trimester, although in a subgroup of patients they can continue throughout the entire pregnancy and can affect the woman's quality of life. A small percentage of women develop a severe form of NVP called hyperemesis gravidarum (HG) that if left untreated may lead to significant maternal morbidity and adverse birth outcomes. Overall, the morbidity in pregnant women with NVP is significant, although it tends to be underestimated. The pathogenesis of NVP remains unclear, but there is consensus that the disorder is multifactorial and that various genetic, endocrine and infectious factors may be involved. The treatment of NVP can be challenging as the optimal targets for therapy are not known. Currently, the therapy used depends on the severity of the disorder and it is focused on improving the symptoms while minimizing risks to mother and fetus. Therapies range from dietary changes, pharmacologic treatment or hospitalization with intravenous fluid replacement and nutrition therapy. The aims of this review are 1) to provide an overview of NVP, 2) to present possible links between the most important factors associated with the pathogenesis of NVP and 3) to discuss the effectiveness and safety of the pharmacologic and non-pharmacologic options available to treat this disorder.