Generic Name

Doxylamine Succinate

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Classification

FDA Approved Indications

• Short-term management of sleep disturbances (insomnia)

Mechanism of Action

Doxylamine succinate blocks central and peripheral H1 histamine receptors, leading to sedation and decreased wakefulness, which promotes sleep.

Dosage and Administration

Adult: 25 mg at bedtime as needed for sleep.

Pediatric: Typically not recommended for children under 12 without physician advice.

Geriatric: Lower doses may be considered due to increased sensitivity to sedatives.

Renal Impairment: Use with caution; dose adjustments may be necessary.

Hepatic Impairment: Use with caution as metabolism may be impaired; consider dose reduction.

Pharmacokinetics

Absorption: Rapidly absorbed from the gastrointestinal tract.

Distribution: Wide distribution including crossing the blood-brain barrier.

Metabolism: Metabolized in the liver via the cytochrome P450 system.

Excretion: Excreted mainly in urine.

Half Life: Approximately 10 hours in healthy adults.

Contraindications

• Hypersensitivity to doxylamine or other antihistamines.
• Use in newborns or premature infants.

Precautions

• Use with caution in elderly, patients with glaucoma, urinary retention, prostate hypertrophy, asthma, or hypertension.

Adverse Reactions - Common

• Drowsiness, dry mouth, dizziness, constipation (Common)

Adverse Reactions - Serious

• Hepatotoxicity, hypersensitivity reactions, urinary retention, severe allergic reactions (Rare)

Drug-Drug Interactions

• CNS depressants (additive sedative effect)
• Anticholinergic drugs (potentiation of anticholinergic effects)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Avoid alcohol and other CNS depressants while taking doxylamine.
• Do not operate machinery or drive until response is known.
• Use for short-term management of sleep disturbances.
• Report any signs of allergic reactions or severe side effects.

Special Considerations

Black Box Warnings:

• Use with caution in older adults due to increased risk of confusion, falls, and paradoxical excitation.
• Potential for dependence with long-term use.

Genetic Factors: Genetic variations in CYP2D6 may affect metabolism.

Lab Test Interference: None noted.

Overdose Management

Signs/Symptoms: Severe sedation, hallucinations, seizures, hyperthermia, tachycardia.

Treatment: Supportive care, activated charcoal if ingestion was recent, maintain airway, cardiovascular support, and symptomatic treatment.

Storage and Handling

Storage: Store at room temperature, 20-25°C (68-77°F).

Stability: Stable under recommended storage conditions.