VITAMINE B6Dernière mise à jour : 2019.12.13 |
|||||||||
Synonyme: | PYRIDOXINE | ||||||||
Administration: | voie orale, parentérale | ||||||||
Classe(s): | |||||||||
Préconception | 0-3 | 4-6 | 7-9 | Périnatal | Allaitement | |
---|---|---|---|---|---|---|
(oui) I | (oui) II | (oui) II | (oui) II | (oui) II | (oui) I | |
aucune info | aucune info | aucune info |
Aucun effet négatif n’a été rapporté avec des doses physiologiques de la vitamine B6. Des doses thérapeutiques peuvent être indiquées dans le traitement de vomissements de la grossesse.
Aucune information spécifique disponible.
La pyridoxine (vitamine B6) traverse la barrière placentaire, et ses taux plasmatiques chez le fœtus sont 5 fois supérieurs aux taux plasmatiques maternels. Des effets nocifs n’ont pas été rapportés chez l’être humain lors de la prise de doses journalières normales recommandées (3mg/j). Cependant, une exposition à des doses élevées de pyridoxine in utéro peut provoquer un syndrome de dépendance à la pyridoxine (avec convulsions) chez le nouveau-né [RCP Vitamine B6 Sterop inj 01 2014]. Aucun effet de tératogénicité n’a été observé [Schaefer].
Pendant la grossesse, les besoins journaliers de la vitamine B6 sont estimés à 1,9 mg [1] [Briggs 2017].
La dose journalière de la vitamine B6 dans des suppléments alimentaires est limitée à 6mg [2].
La pyridoxine (10 à 100mg/jour) a été utilisée dans le traitement de vomissements de la grossesse avec un succès variable. La dose totale s’élevait à 1500 à 2500 mg. Deux études de petite dimension offraient un résultat positif : dans une étude randomisée en double aveugle versus placebo, les patients du groupe actif avaient reçu 25 mg de pyridoxine par voie orale toutes les 8 heures pendant 72 heures (n=31; 9ième de la grossesse); dans une deuxième étude, la dose administrée s’élevait à 10 mg de pyridoxine toutes les 8 heures pendant 5 jours (n=167; 11ieme semaine de la grossesse) [Briggs 2017].
Chez l´animal:Il n'y a pas d'étude de tératogenèse disponible chez l'animal [RCP Vitamine B6 Sterop inj 01 2014].
Deuxième trimestre:Voir premier trimestre.
Chez l´animal:Aucune donnée spécifique disponible.
Troisième trimestre :Voir premier trimestre.
Chez l´animal:Aucune donnée spécifique disponible.
Période périnatale (toujours tenir compte des données relatives au trimestre en cours) :Aucune donnée supplémentaire n’est disponible.
Chez l´animal:Aucune donnée spécifique disponible.
Observance:Aucune donnée spécifique disponible.
Chez l´animal:Aucune donnée spécifique disponible.
L2
La vitamine B6 est excrétée dans le lait maternel. Toutefois, des effets nocifs n’ont pas été rapportés en cas de prise de doses journalières normales recommandées (3 mg/jour) [RCP Vitamine B6 Sterop inj 01 2014]. En cas de carences en vitamine B6 chez des mères allaitantes, il est conseillé de limiter les apports supplémentaires à max. 40mg/jour [Hale].
Une carence en pyridoxine peut survenir entre autres chez les nourrissons (suite à certaines maladies métaboliques), chez les alcooliques et lors d'un traitement chronique par l'isoniazide. L'hyperémèse gravidique et d'autres formes de nausées et de vomissements ne sont pas une indication [CBIP].
Chez l´animal:Aucune donnée spécifique disponible.
Préconception | Grossesse | Allaitement | ||||
---|---|---|---|---|---|---|
(oui) III | (oui) III | |||||
aucune info | aucune info | ← Préservatif / Abstinence |
Aucune donnée spécifique disponible
Aucune donnée spécifique disponible.
Chez l´animal:Aucune donnée spécifique disponible.
Aucune donnée spécifique concernant le passage via le sperme n'est disponible.
Chez l´animal:Aucune donnée spécifique disponible.
Hale, Medications and Mothers´Milk, 17th Edition, 2017
Notice scientifique (RCP Résumé des caractéristiques du produit)
Briggs G, Freeman R, Yaffe S. Drugs in Pregnancy and Lactation, 10th edition, Philadelphia 2015
Briggs G, Freeman R, Yaffe S. Drugs in Pregnancy and Lactation, 11th edition, Philadelphia 2017
Schaefer, Drugs during pregnancy and lactation, 3th Edition, 2015
[1] KNMP Informatorium Medicamentorum 2019: p.1512
[2] Arrêté Royale du 3 mars 1992 concernant la mise dans le commerce de nutriments et de denrées alimentaires auxquelles des nutriments ont été ajoutés (B.S. 15.IV.1992).
Aucune donnée spécifique disponible.
Nausées et vomissements : Source : Motherisk (consulté le 27 octobre 2014)
Nausea and vomiting of pregnancy (NVP) is the most common medical condition of pregnancy, affecting up to 80% of all pregnant women to some degree. In most cases, it subsides by the 16th week of pregnancy (nvdr : percentage is naar de hoge kant; meestal voorbij rond de 12de week), although up to 20% of women (nvdr : hoge schatting!) continue to have symptoms throughout pregnancy. Severe NVP (hyperemesis gravidarum) affects less than 1% of women, but it can be debilitating, sometimes requiring hospitalization and rehydration. Women suffer not only physically, but also psychologically, which has been documented in a number of studies. In addition, some women have decided to terminate their pregnancies rather than tolerate the severe symptoms.
Pharmacotherapy
We systematically reviewed the literature pertaining to the symptomatic treatment of NVP from January 1998 to September 2006. The updated algorithm includes this recent relevant published data. The drug of choice for treatment in Canada remains Diclectin, the delayed-release combination of doxylamine and vitamin B6 (nvdr : doxylamine niet als monopreparaat in België).
Other pharmacologic treatments with relatively good safety profiles and varying degrees of effectiveness include antihistamines, ondansetron, phenothiazines, metoclopramide, and corticosteroids. Herbal products such as vitamin B6 and ginger have also been used safely with varying degrees of effectiveness.
Nonpharmacologic treatments
Acupressure and acupuncture at acupoint P6 have been used with varying degrees of effectiveness.
Overcoming secondary symptoms
There are several strategies that have been helpful in dealing with secondary symptoms related to NVP.
Diet
Mixing solids and liquids can increase nausea and vomiting because it can make the stomach feel fuller and, in some women, can cause gas, bloating, and acid reflux. Eating small portions every 1 to 2 hours and eating and drinking separately can be helpful. For example, eat a small portion of food, wait 20 to 30 minutes, then take some liquid. Remind women that they should eat whatever they can tolerate. Other than in the case of severe malnutrition, fetuses generally receive the nutrition they require—sometimes to the detriment of the mother. For example, the calcium depletion from the fetus can cause a mother’s teeth to decay. There are supplements on the market that the mother can consume if she is unable to digest a full meal, such as liquid supplements, puddings, and protein bars to replace the lack of essential maternal nutrients.
Fluids
A pregnant woman should try to consume at least 2 litres of fluids daily in small amounts taken frequently. Colder fluids, including ice chips and Popsicles, appear to be easier to tolerate and can decrease the metallic taste in the mouth. There are also commercial products available that maintain the electrolyte balance (sports drinks, etc).
Prenatal vitamins
Vitamins can worsen nausea, primarily because of the iron content and large size. The most common side effects from using prenatal vitamins are constipation, nausea, and vomiting. In the first trimester, a woman can take folic acid alone or take a multivitamin that does not contain iron, as this form does not appear to increase NVP. Later on in the pregnancy when the NVP subsides,she can resume taking her regular multivitamin.
Antacids
Conditions such as heartburn, acid reflux, indigestion, gas, or bloating can also exacerbate NVP and can be very uncomfortable. It is important that these symptoms are treated effectively. Minor symptoms can be treated with antacids containing calcium carbonate; however, if these are not effective, histamine (H2) blockers and proton pump inhibitors are safe to take. In addition, there are over-the-counter products available that can help with excess gas and bloating. Some women have reported becoming lactose-intolerant during pregnancy; they should switch to lactose-free products. There is also some evidence that effectively treating Helicobacter pylori with antibiotics can mitigate the symptoms of NVP.
Fibre for constipation
Women who do not consume enough fibre should try to increase their fibre intake by eating well-tolerated high-fibre foods (eg, cereal, dried fruit). If this is not effective, they can try over-the-counter products such as psyllium and a stool softener (eg, docusate sodium).
Spitting and mouth washing for excessive saliva
Women should be advised not to swallow excessive saliva, as this can increase the symptoms of NVP. Spitting out the saliva and frequent mouth washing can be helpful.
Management
Because NVP affects a large number of pregnant women, some with serious consequences, it cannot be ignored, especially when there are safe and effective treatments available. Inquiring about NVP when interviewing pregnant women during their first visits to health care providers is an essential part of the history. Many women do not volunteer this information because their symptoms might have been minimized by others, or theyhave been informed that it is a normal part of pregnancy and something they have to tolerate. Health care providers should be aware of the evidence-based information regarding various treatment modalities and offer them to their patients when appropriate. Nausea and vomiting in pregnancy manifests itself differently in each woman, and its management should be tailored for each individual. Nausea alone should not be minimized, as this can affect the quality of life as much as—or more than—vomiting. Nausea treatments can be either pharmacologically based or holistic, or an effective combination of both. Timing of NVP treatment is also important, as early treatment can prevent a more severe form from occurring, reducing the possibility of hospitalization, time lost from paid employment, and emotional and psychological problems. It is important that women and their health care providers understand that the benefits of safe and effective NVP treatment predominantly outweigh any potential or theoretical risks to the fetus; thus, all treatment options should be considered.
Pour les références, veuillez suivre le lien suivant : http://www.motherisk.org/women/updatesDetail.jsp?content_id=875