From the Guidelines
Doxylamine is not recommended for the treatment of chronic insomnia disorder due to its potential for adverse effects and the availability of alternative treatments with a lower risk of harm. For insomnia, the recommended dosage of doxylamine is 25 mg taken orally 30 minutes before bedtime, but its use should be limited to short-term treatment (7-10 days maximum) due to the risk of tolerance development 1. For allergies, the typical dosage is 12.5 mg every 4-6 hours as needed, not exceeding 75 mg in 24 hours. Doxylamine is a first-generation antihistamine that works by blocking histamine receptors in the brain, which helps induce drowsiness for sleep and reduces allergy symptoms. Some key points to consider when using doxylamine include:
- Side effects may include daytime drowsiness, dry mouth, blurred vision, and constipation.
- Doxylamine should be avoided if you have certain conditions like glaucoma, enlarged prostate, or breathing problems.
- Don't combine with alcohol or other sedatives as this can dangerously increase drowsiness.
- For elderly patients, a lower starting dose (12.5 mg for sleep) is recommended due to increased sensitivity to side effects.
- If insomnia persists beyond 10 days, consult a healthcare provider as this may indicate an underlying condition requiring different treatment 1. It's also important to note that the 2019 Beers Criteria carry a strong recommendation to avoid antihistamines, including doxylamine, in older adults due to their antimuscarinic adverse effect profile 1.
From the FDA Drug Label
Directions • adults and children 12 years of age and over: take one tablet 30 minutes before going to bed; take once daily or as directed by a doctor • children under 12 years of age: do not use Active ingredient (in each tablet) Doxylamine succinate 25 mg
The recommended dosage and usage of Doxylamine for insomnia is to take one tablet (25 mg) 30 minutes before going to bed, and once daily or as directed by a doctor. For allergies, there is no specific dosage information provided in the drug labels.
- Adults and children 12 years of age and over can use Doxylamine.
- Children under 12 years of age should not use Doxylamine 2.
From the Research
Dosage and Usage of Doxylamine
- The recommended dosage of Doxylamine for insomnia is not explicitly stated in the provided studies, but it is mentioned that doxylamine is effective for up to four weeks 3.
- A study compared the pharmacokinetics of two strengths (12.5 mg and 25 mg) of doxylamine hydrogen succinate film-coated tablets and found that exposure to doxylamine was proportional over the therapeutic dose range of 12.5-25 mg in healthy volunteers 4.
- Another study developed a doxylamine succinate intranasal metered-dose delivery system, but found that none of the intranasal dose levels produced a mean maximum plasma concentration above the 50 ng/mL target level or a time to maximum concentration shorter than that of the oral tablet 5.
- A multicenter comparative randomized study found that short-term doxylamine intake causes significant positive clinical effect in short-term insomnia with satisfactory acceptability by patients, with no significant differences in clinical efficacy compared to donormyl 6.
Usage for Insomnia and Allergies
- Doxylamine is commonly proposed by pharmacists as a sleeping pill for occasional insomnia in adults 7.
- It is suggested that the use of doxylamine may be appropriate for treating insomnia in the last third of the night, particularly in light of knowledge about the role of histamine H1 inverse agonist drugs in the treatment of insomnia 7.
- Doxylamine is also used as an antihistamine for the treatment of allergies, but the provided studies do not specifically address its usage for this purpose.
- The treatment of chronic insomnia in adults typically focuses on nonpharmacologic therapies, but pharmacologic agents such as doxylamine may be considered if these approaches are ineffective 3.