From the Research
Gabapentin is generally considered safer and less neurotoxic than diphenhydramine for long-term PRN use in treating anxiety.
Key Considerations
- Gabapentin, typically started at 100-300mg doses taken as needed up to three times daily (maximum 3600mg/day), works by modulating calcium channels and GABA neurotransmission without significant cognitive impairment when used appropriately 1.
- Diphenhydramine, while effective short-term at 25-50mg doses, has anticholinergic properties that can cause significant cognitive side effects including memory problems and confusion, particularly concerning with regular use in older adults.
- Long-term diphenhydramine use has been associated with increased dementia risk, while gabapentin generally maintains a better cognitive safety profile over extended periods 2.
Important Safety Information
- Gabapentin requires careful dosing adjustments for kidney impairment and can cause sedation, dizziness, and potential physical dependence with prolonged use.
- Neither medication should be abruptly discontinued after extended use, and both should be initiated under medical supervision with regular follow-up to monitor effectiveness and side effects.
- The most recent and highest quality study 3 suggests that cognitive behavioral therapy (CBT) may be effective for discontinuing benzodiazepines, which could be considered as an alternative or adjunct to gabapentin or diphenhydramine for anxiety management.
Clinical Recommendations
- Consider gabapentin as a safer alternative to diphenhydramine for long-term PRN use in treating anxiety, due to its more favorable cognitive safety profile.
- Monitor patients closely for potential side effects and adjust dosing as needed to minimize risks.
- Regular follow-up and medical supervision are crucial to ensure safe and effective use of these medications.