Can Doxylamine be reconstituted?

Doxylamine Reconstitution

Doxylamine is not available in a formulation that can be reconstituted for parenteral administration. Based on available evidence, doxylamine is only available as oral tablets, capsules, or in combination products, and there is no indication that it can be reconstituted for intravenous, intramuscular, or other parenteral use 1.

Available Formulations of Doxylamine

Doxylamine succinate is primarily available in the following forms:

• Oral tablets (typically 12.5 mg and 25 mg strengths) 2
• Combination products with other medications (e.g., with pyridoxine for nausea and vomiting of pregnancy) 1

Clinical Applications and Administration

Doxylamine is an H1-receptor antagonist that is commonly used for:

1. Treatment of insomnia - Available as an over-the-counter sleep aid 3
2. Management of nausea and vomiting in pregnancy - Often combined with pyridoxine (vitamin B6) 1

For nausea and vomiting of pregnancy:

• Available in 10 mg/10 mg and 20 mg/20 mg combinations with pyridoxine 1
• Recommended by ACOG for persistent nausea and vomiting of pregnancy refractory to non-pharmacologic therapy 1

Safety Considerations

If considering alternative routes of administration, be aware of these important safety concerns:

• Overdose risk: Doxylamine overdose has been associated with severe complications including rhabdomyolysis and acute renal failure 4
• Addiction potential: Case reports have documented doxylamine addiction with doses escalating from therapeutic levels (25 mg/day) to much higher doses (125 mg/day) 5
• Toxicity: Post-mortem toxicological analyses have identified doxylamine in suicide cases, often in combination with other substances 6

Alternative Parenteral Antihistamines

If a parenteral antihistamine is needed for clinical situations where doxylamine might otherwise be considered, alternative options include:

• Diphenhydramine: Available for parenteral administration at 1-2 mg/kg or 25-50 mg/dose 1
• Promethazine: Available for parenteral use for nausea and vomiting 1

Conclusion

Doxylamine is only available in oral formulations and cannot be reconstituted for parenteral use. For situations requiring parenteral antihistamine administration, alternative medications like diphenhydramine or promethazine should be considered based on the clinical indication.