BONJESTA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for BONJESTA (BONJESTA).
Bonjesta (doxylamine/pyridoxine) is a combination of an antihistamine (doxylamine) and vitamin B6 (pyridoxine). Doxylamine centrally inhibits histamine H1 receptors in the vomiting center, reducing nausea and vomiting. Pyridoxine acts as a cofactor in neurotransmitter synthesis, potentially modulating nausea pathways.
| Metabolism | Doxylamine undergoes hepatic metabolism via N-demethylation (CYP450), and pyridoxine is converted to pyridoxal phosphate in the liver. |
| Excretion | Renal excretion accounts for approximately 70-80% of the dose, primarily as metabolites (doxylamine metabolites and pyridoxine metabolites), with less than 5% excreted unchanged. Fecal elimination is minimal (<5%). |
| Half-life | Doxylamine: terminal elimination half-life of 10-12 hours; pyridoxine: half-life of 15-20 days (due to tissue binding). Clinically, the half-life supports once-daily dosing at bedtime. |
| Protein binding | Doxylamine: approximately 30-50% bound to plasma proteins (mainly albumin). Pyridoxine: negligible protein binding. |
| Volume of Distribution | Doxylamine: Vd of approximately 3-4 L/kg, indicating extensive tissue distribution. Pyridoxine: Vd of approximately 0.6-0.7 L/kg (reflects total body water). |
| Bioavailability | Oral bioavailability: doxylamine approximately 70-80% (first-pass metabolism); pyridoxine approximately 60-80% (saturable absorption). |
| Onset of Action | Oral administration: onset of clinical effect (antiemetic) occurs within 30-60 minutes, with peak effect at 2-4 hours. |
| Duration of Action | Duration of antiemetic effect is approximately 6-8 hours after a single dose, consistent with doxylamine's half-life. For sleep aid effect, duration may extend to 8-10 hours. |
For nausea and vomiting of pregnancy: 10 mg doxylamine succinate and 10 mg pyridoxine hydrochloride orally at bedtime on an empty stomach; if symptoms are not controlled, increase to 10 mg doxylamine and 10 mg pyridoxine in the morning and 10 mg doxylamine and 10 mg pyridoxine at bedtime, maximum 40 mg doxylamine and 40 mg pyridoxine per day.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | No dose adjustment recommended for mild to moderate renal impairment. For severe renal impairment (CrCl < 30 mL/min), avoid use due to risk of accumulation. |
| Liver impairment | No dose adjustment recommended for mild to moderate hepatic impairment (Child-Pugh A or B). For severe hepatic impairment (Child-Pugh C), avoid use as safety has not been established. |
| Pediatric use | Not indicated for use in pediatric patients for the treatment of nausea and vomiting of pregnancy. Safety and efficacy in children have not been established. |
| Geriatric use | Not indicated for use in geriatric patients for the treatment of nausea and vomiting of pregnancy. Clinical studies did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for BONJESTA (BONJESTA).
| Breastfeeding | Doxylamine and pyridoxine are excreted into breast milk in small amounts. M/P ratio for doxylamine is approximately 0.5; for pyridoxine, data limited. No adverse effects reported in infants. Use with caution, monitor for sedation. |
| Teratogenic Risk | BONJESTA (doxylamine/pyridoxine) is a Category A drug for nausea/vomiting in pregnancy. No evidence of fetal harm in first trimester; risk in second and third trimesters is minimal based on large observational studies. |
| Fetal Monitoring |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
["Hypersensitivity to doxylamine, pyridoxine, or any component.","Concomitant use with monoamine oxidase inhibitors (MAOIs).","Breastfeeding (due to potential for infant sedation).","Children under 18 years (not indicated)."]
| Precautions | ["May cause drowsiness; avoid driving or operating heavy machinery.","Concomitant use with CNS depressants (e.g., alcohol, sedatives) may enhance sedation.","Use with caution in patients with asthma, glaucoma, or urinary retention.","Do not exceed recommended dosage."] |
| Food/Dietary | No significant food interactions. Avoid grapefruit juice? (not studied, but generally not recommended with many drugs due to CYP3A4 inhibition; doxylamine is primarily CYP2D6 substrate). Take with or without food. Avoid high-fat meals? (may delay absorption but not clinically significant). |
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| Monitor maternal sedation, anticholinergic effects (dry mouth, blurred vision). Fetal monitoring not routinely required unless maternal overdose or severe adverse reactions. |
| Fertility Effects | No known adverse effects on fertility in males or females based on available data. |
| Clinical Pearls | BONJESTA (doxylamine/pyridoxine) is FDA-approved for nausea/vomiting in pregnancy (NVP). Use lowest effective dose; titrate slowly. Contraindicated in those taking MAOIs (hypertensive crisis risk). Antihistaminergic effects may cause sedation; avoid concurrent CNS depressants. Onset of action ~1-2 hours for doxylamine. Not for severe hyperemesis gravidarum requiring IV fluids. |
| Patient Advice | Take at bedtime to minimize daytime drowsiness. · If symptoms persist into daytime, take morning dose as directed. · Avoid driving or operating heavy machinery until you know how this drug affects you. · Do not take with alcohol or other sedatives. · If you miss a dose, skip it; do not double up. · Contact your doctor if vomiting persists or you experience severe abdominal pain. · Store at room temperature, away from moisture and heat. |