Nausea and vomiting of pregnancy
Nausea and vomiting during the first trimester of pregnancy in 70–80% of women. Standard approach: dietary changes, small frequent meals. First-line agent: pyridoxine (10–25 mg up to 4 times daily) alone or in combination with doxylamine (Diclectin/Diclegis).
ICD-10 O214 drugs
Also known as: NVP, Morning sickness
Drugs used for this condition
- ADoxylamineFirst line · First-generation antihistamine (ethanolamine); antiemetic in combination with pyridoxineDoxylamine 10 mg + pyridoxine 10 mg (Cariban in Spain) is first-line therapy for moderate nausea and vomiting in pregnancy. AEMPS authorises it from the first trimester; ACOG 2018 and SEGO 2023 position it on the first step after pyridoxine monotherapy. Safety is supported by 70 years of clinical experience (since 1956); meta-analyses of more than 200,000 pregnancies show no teratogenicity. Dosing: 1–2 capsules at bedtime, adding morning and afternoon doses if symptoms persist. The main adverse effect is drowsiness, so therapy starts with the evening dose.
- ADoxylamine/pyridoxineFirst line · Combination of H1-antihistamine and vitamin B6First-line for mild-to-moderate nausea and vomiting of pregnancy per ACOG 2018 and the Spanish SEGO 2022. Starting dose 1 capsule at bedtime; with persistent symptoms, increase to 1 capsule in the morning and 2 at bedtime (up to 40 mg doxylamine and 40 mg pyridoxine daily). Non-pharmacological measures are recommended before drug therapy: small frequent meals, ginger, P6 acupressure. Safety confirmed in a 200,000-pregnancy cohort without described teratogenicity.
- APyridoxine (vitamin B6)First line · Vitamins. CoenzymePyridoxine 10–25 mg up to 4 times daily alone or with doxylamine (Diclegis/Bonjesta) is first-line for nausea and vomiting of pregnancy. ACOG 2018 recommends pyridoxine as initial pharmacotherapy after dietary measures fail. Cochrane 2015 showed clinically meaningful symptom reduction. Safe for the foetus and mother at doses up to 200 mg daily.
- BMetoclopramideSecond line · Prokinetic, dopamine D2 receptor antagonistSecond-line option in nausea and vomiting of pregnancy after doxylamine-pyridoxine. Epidemiological data show no increase in major malformations.
How to read tiers A–F
Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.
- AStrong evidence – first or second line in international guidelines
- BRecommended in selected cases
- CStudy data contradict each other
- DBenefit not proven, no documented harm
- FDocumented harm, or risk without benefit