Dosing & Uses
Dosing Forms & Strengths
doxylamine/pyridoxine
tablet, delayed-release
- 10mg/10mg (Diclegis)
tablet, extended-release
- 20mg/20mg (Bonjesta)
- Consist of enteric-coated core of 10 mg doxylamine and 10 mg pyridoxine for extended-release, and immediate-release coating of 10 mg doxylamine and 10 mg pyridoxine
Nausea & Vomiting of Pregnancy
Indicated for women who do not respond to conservative management
Diclegis
- 2 delayed-release tablets PO on a daily basis at bedtime
- If symptoms not adequately controlled, increase dose to 4 tablets each day (1 tab in AM, 1 tab mid-afternoon, and 2 tabs at bedtime)
Bonjesta
- Day 1: Take 1 extended-release tablet PO at bedtime
- If this dose adequately controls symptoms the next day, continue taking 1 tablet daily at bedtime only
- If symptoms persist on Day 2, increase the daily dose to 1 tablet in the morning and 1 tablet at bedtime
- Not to exceed 2 tablets/day (ie, 1 tab in the morning and 1 tab at bedtime)
- Take daily and not on an as needed basis; reassess continued need for therapy as pregnancy progresses
Dosing Considerations
Not studied in women with hyperemesis gravidarum
Safety and efficacy not established
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Adverse Effects
>10%
Somnolence (14.3%)
Postmarketing Reports
Cardiac disorders: Dyspnea, palpitation, tachycardia
Ear and labyrinth disorders: Vertigo
Eye disorders: Vision blurred, visual disturbances
Gastrointestinal disorders: Abdominal distension, abdominal pain, constipation, diarrhea
General disorders and administration site conditions: Chest discomfort, fatigue, irritability, malaise
Immune system disorders: Hypersensitivity
Nervous system disorders: Dizziness, headache, migraines, paresthesia, psychomotor hyperactivity
Psychiatric disorders: Anxiety, disorientation, insomnia, nightmares
Renal and urinary disorders: Dysuria, urinary retention
Skin and subcutaneous tissue disorders: Hyperhidrosis, pruritus, rash, rash maculopapular
Warnings
Contraindications
Hypersensitivity to drug or excipients
Concomitant use with MAO inhibitors
Cautions
Not evaluated for use in hyperemesis gravidarum
Coadministration with alcohol and other CNS depressants may cause additive sedation and is not recommended; combination may cause severe drowsiness leading to falls or accidents
Somnolence due to anticholinergic effects is common; avoid activities requiring mental alertness
Anticholinergic effects may exacerbate conditions such as asthma, increased intraocular pressure, narrow angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, and urinary bladder-neck obstruction
Drug interaction overview
- False positive drug screens for methadone, opiates, and PCP can occur with doxylamine succinate/pyridoxine hydrochloride use; confirmatory tests, such as Gas Chromatography Mass Spectrometry (GC-MS), should be used to confirm identity of substance in the event of positive immunoassay result
Pregnancy & Lactation
Pregnancy
Intended for treatment of nausea and vomiting of pregnancy in women who do not respond to conservative management; maternal risks are discussed throughout the labeling; no increased risk for congenital malformations reported in epidemiologic studies in pregnant women
Lactation
Women should not breastfeed while on therapy; molecular weight of doxylamine succinate is low enough that passage into breast milk can be expected; excitement, irritability and sedation reported in nursing infants presumably exposed to doxylamine succinate through breast milk; infants with apnea or other respiratory syndromes may be particularly vulnerable to sedative effects of drug resulting in worsening of their apnea or respiratory conditions
Pyridoxine hydrochloride is excreted into breast milk; adverse events in infants presumably exposed to pyridoxine hydrochloride through breast milk reported
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Mechanism of action for efficacy for morning sickness is unknown
Doxylamine: Ethanolamine derivative antihistamine
Pyridoxine: Vitamin B6 analog
Absorption
Peak plasma time: 7.8 hr (doxylamine); 5.6 hr (pyridoxine)
Peak plasma concentration: 168.6 ng/mL (doxylamine); 46.1 ng/mL (pyridoxine)
AUC: 3721 ng•hr/mL (doxylamine); 64.5 ng•hr/mL (pyridoxine)
Distribution
Protein bound: Pyridoxine is highly protein bound (primarily to albumin); main active metabolite (PLP) accounts for at least 60% of circulating vitamin B6 concentrations
Metabolism
Doxylamine is biotransformed in the liver by N-dealkylation to its principle metabolites N-desmethyldoxylamine and N, N-didesmethyldoxylamine
Pyridoxine is a prodrug primarily metabolized in the liver to pyridoxal 5’-phosphate (PLP), pyridoxal, pyridoxamine, and pyridoxamine 5’-phosphate
Elimination
Half-life: 12.5 hr (doxylamine); 0.5 hr (pyridoxine)
Excretion: Principle metabolites of doxylamine excreted in urine
Administration
Oral Administration
Take on empty stomach with water; food further delays onset of action and lowers peak levels
Swallow tablet whole, do not chew, crush, or split
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Formulary
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