Tony asked
I take Abilify daily and am always concerned about drug interactions. Is it safe to take Abilify with Benadryl?
Answer
The use of Abilify (aripiprazole) and Benadryl (diphenhydramine) may require monitoring as there is a moderate drug interaction between these two medications.
There are actually two potential interactions between Abilify and Benadryl:
- Both can cause CNS (central nervous system) depression and can cause additive sedation and dizziness. In addition, both drugs have anti-cholenergic effects, which can cause dry mouth, dry eyes and constipation.
- Benadryl is a weak inhibitor of the metabolizing enzyme CYP2D6, which is responsible for Abilify metabolism. Therefore, use of Benadryl with Abilify can increase concentrations of Abilify in the body, increasing the risk of side effects.
What Is Abilify?
Abilify is indicated for the treatment of bipolar disorder, autism and major depressive disorder as an adjunct therapy. Abilify is known as an "atypical antipsychotic" and works as a partial agonist on dopamine and serotonin receptors of the brain.
The most common side effects with Abilify are:
- Weight gain
- Constipation
- Dry mouth
- Dry eyes
- Causea
Abilify also has the potential to cause drowsiness and sedation but this side effect is most common when initiating or changing a dose.
What Is Benadryl?
Benadryl is a first-generation antihistamine with a relatively short duration of action (~4-6 hours) and strong sedative effects. It is commonly used to prevent seasonal allergy symptoms (e.g. sneezing, watery eyes) and well at treat allergic reactions. Due to its sedative effects, it is also a commonly used ingredient in over the counter sleep medications, such as Tylenol PM.
Benadryl is generally well tolerated but can cause dizziness, drowsiness, dry mouth, dry eyes and constipation with long term use.
Taking Abilify With Benadryl
As discussed above, when Abilify is used in combination with Benadryl, there is a potential for additive sedation and anticholinergic effects. Their use together isn't contraindicated, but it is important to know about the increased risk of adverse effects.
The clinical significance of CYP2D6 metabolizing enzyme inhibition by Benadryl isn't well known, but it is thought to be a weak inhibitor and shouldn't cause significant changes to Abilify concentrations in the body.
