Nurses Compass
Drug Guide
Doxylamine Succinate and Pyridoxine Hydrochloride
Classification
Therapeutic: Antiemetic for nausea and vomiting during pregnancy
Pharmacological: Antihistamine (Doxylamine), Vitamin B6 supplement (Pyridoxine)
FDA Approved Indications
- Nausea and vomiting of pregnancy
Mechanism of Action
Doxylamine is an antihistamine that relieves nausea by blocking H1 histamine receptors, and Pyridoxine (vitamin B6) is involved in amino acid metabolism and neurotransmitter synthesis, which helps reduce nausea.
Dosage and Administration
Adult: Typically, 10 mg of Doxylamine and 10-25 mg of Pyridoxine at bedtime or divided throughout the day. Specific dosing depends on the formulation and patient response.
Pediatric: Not established for pediatric use; consult healthcare provider.
Geriatric: Use with caution; start at lower doses due to increased sensitivity and risk of side effects.
Renal Impairment: Adjust dose based on severity of impairment.
Hepatic Impairment: Use caution; no specific adjustments established.
Pharmacokinetics
Absorption: Well absorbed from gastrointestinal tract.
Distribution: Widely distributed; crosses blood-brain barrier.
Metabolism: Hepatic metabolism for Doxylamine; Pyridoxine metabolized in the liver.
Excretion: Renal excretion of metabolites.
Half Life: Doxylamine approximately 10 hours; Pyridoxine approximately 25-33 hours.
Contraindications
- Known hypersensitivity to Doxylamine or Pyridoxine.
- Narrow-angle glaucoma.
- Acute asthma exacerbation.
- Pregnancy and lactation (see notes).
Precautions
- Use with caution in elderly, patients with urinary retention, BPH, or gastric retention.
- Potential for sedation and anticholinergic effects.
Adverse Reactions - Common
- Drowsiness (Common)
- Dizziness (Common)
- Dry mouth (Common)
Adverse Reactions - Serious
- Sedation leading to impairment of daily activities (Serious if excessive)
- Hypersensitivity reactions (Rare)
- Potential exacerbate glaucoma or urinary retention (Serious in susceptible individuals)
Drug-Drug Interactions
- Centrally acting CNS depressants, alcohol may increase sedative effects.
- Anticholinergic drugs may have additive effects.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor for signs of excessive sedation, anticholinergic effects, and pregnancy symptoms.
Diagnoses:
- Risk for injury related to sedation
- Risk for falls in elderly
Implementation: Administer at recommended doses, assess patient response, and educate on sedation precautions.
Evaluation: Efficacy in reducing nausea, minimal adverse effects.
Patient/Family Teaching
- Take as directed, preferably at bedtime.
- Caution about drowsiness and operating machinery.
- Avoid alcohol and other CNS depressants.
- Report any unusual side effects or allergic reactions.
Special Considerations
Black Box Warnings:
- Use during pregnancy has been associated with a potential increased risk of fetal harm, though benefits may outweigh risks in certain cases.
Genetic Factors: Genetic variations in metabolism may affect drug levels.
Lab Test Interference: None reported.
Overdose Management
Signs/Symptoms: Extreme drowsiness, confusion, hallucinations, anticholinergic effects, potentially coma.
Treatment: Supportive care, activated charcoal if within 1 hour of ingestion, airway management, and symptomatic treatment.
Storage and Handling
Storage: Store at room temperature, away from moisture and light.
Stability: Stable under normal conditions.