Doxylamine + Pyridoxine

Indications

Doxylamine + Pyridoxine is used for: Nausea & Vomiting of Pregnancy

Adult Dose

Oral Nausea & Vomiting of Pregnancy Indicated for the treatment of nausea and vomiting of pregnancy in women who do not respond to conservative management Delayed-release Tablet 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) Conventional Tablet Initially, take one tablet orally at bedtime (Day 1). If this dose adequately controls symptoms the next day, continue taking one tablet daily at bedtime only. If symptoms persist, increase the daily dose to one tablet in the morning and one tablet at bedtime. The maximum recommended dose is two tablets per day, one in the morning and one at bedtime.

Child Dose

<18 years: Safety and efficacy not established

Renal Dose

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

Contra Indications

Hypersensitivity MAO inhibitors intensify and prolong doxylamine’s adverse effects (ie, anticholinergic, CNS)

Precautions

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 Lactation: Do not breast feed; doxylamine molecular weight is low enough to distribute into human breast milk Excitement, irritability, and sedation reported in nursing infants presumably exposed to doxylamine through breast milk; infants with apnea or other respiratory syndromes may be particularly vulnerable to the sedative effects resulting in worsening of apnea or respiratory conditions Pyridoxine is excreted in breast milk; there have been no reports of adverse effects in infants

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

Interactions

Adverse Effects

Side effects of Doxylamine + Pyridoxine : >10% Somnolence (14.3%)

Mechanism of Action

Doxylamine: Ethanolamine derivative antihistamine Pyridoxine: Vitamin B6 analog Doxylamine is an antihistamine that blocks Histamine (H1) receptor. It affects the vestibular system and decreases the stimulation of the vomiting center. Its mascarinic receptor inhibition may also play a role in antihistamine antiemetic activity. Pyridoxine (Vitamin B6) is a vitamin used to prevent nausea and vomiting due to its antiemetic properties.