gloybee asked
I quit taking Tylenol 3 with codeine 30 Hours ago! Can I now safely take benedryl allergy?
Answer
It generally isn't recommended to take codeine and Benadryl (diphenhydramine) together as both are CNS (central nervous system) depressants. Use of both together can result in additive side effects, including:
- Sedation
- Respiratory depression
- Constipation
Additionally, Benadryl inhibits the metabolizing enzyme CYP2D6, which converts codeine to morphine in our system. Therefore, Benadryl use may decrease the analgesic effect of codeine (as it will less efficiently be converted to morphine).
In terms of how long codeine needs to be discontinued for before taking Benadryl, it will vary by individual. However, codeine has a relatively short half-life, around 3 to 4 hours and will be completely metabolized and eliminated within 24 hours. In your situation, having taken codeine over 30 hours ago, it would be considered safe to take Benadryl as most, if not all of the codeine will have been eliminated from your system.
