Doxylamine Succinate
Indications
Doxylamine Succinate is used for:
Itching, Sneezing, Watery eyes, Runny nose, Common cold, Insomnia, Hypersensitivity reactions
Adult Dose
Oral
Hypersensitivity reactions
Adult: 25 mg every 4-6 hr. Max: 150 mg daily.
Insomnia
Adult: 25 mg given 30 minutes before retiring at night.
Elderly: Avoid use in elderly because of high incidence of anticholinergic effects
Child Dose
Insomnia
<12 years: Not recommended
>12 years: 25 mg PO qHS PRN 30 min before bedtime
Renal Dose
Administration
Should be taken with food. Take w/ food or milk.
Contra Indications
Severe liver disease; avoid alcohol; premature infants or full-term neonates.
Precautions
May impair ability to drive and operate machinery. Angle-closure galucoma, urinary retention, prostatic hypertrophy or pyloroduodenal obstruction; epilepsy; hepatic impairment. Elderly. Lactation.
Lactation: excretion in milk unknown
Pregnancy-Lactation
Pregnancy Category: B
Lactation: excretion in milk unknown
Interactions
Doxylamine enhances effects of CNS depressants eg alcohol, barbiturates, hypnotics, opioid analgesics, anxiolytic sedatives and antipsychotics. Atropine, tricyclic antidepressants (TCAs), MAOIs. It can mask signs of ototoxicity caused by aminoglycosides. INH, penicillamine and OC require greater pyridoxine dose. Pyridoxine reduces the effects of levodopa, phenobarb and phenytoin.
Adverse Effects
Side effects of Doxylamine Succinate :
Acute dystonic reactions and long-lasting impaired consciousness in child. CNS depression including slight drowsiness to deep sleep, lassitude, dizziness, incoordination. Headache, psychomotor impairment and antimuscarinic effects.
Rarely rashes and hypersensitivity reactions, blood disorders, convulsions, sweating, myalgia, extrapyramidal effects, tremor, confusion, tinnitus, hypotension, hair loss.
Mechanism of Action
Doxylamine is an antihistamine derived from monoethanolamine possessing antimuscarinic and pronounced sedative effects.Competes for H1-receptor sites on target cells; has anticholinergic effects, which depresses labyrinthine function, blocks chemoreceptor trigger zone, and diminishes vestibular stimulation.