Is Benadryl a safe medication to use? Benadryl or diphenhydramine has been available since 1946, before drugs were required to pass rigorous testing. Benadryl is commonly used and it is the most commonly recommended antihistamine for children over the past several years by physicians and pharmacists. Benadryl will frequently be chosen because of brand recognition to treat allergy symptoms as well as insomnia. However despite its frequent use and perception that it is the safest and most effective option, benadryl is in fact not. It is associated with a large variety of adverse effects and toxicities. There are muchm more safer and more effective antihistamines that are widely available.
Sedation is commonly seen with benadryl, in fact many people use it to treat their insomnia. The sedative effect of benadryl is related to its easy penetration of the blood-brain barrier, causing drowsiness and sedation. This can lead to sedation the next day, leading to poor attention, reduced memory and poor sensory motor performance.
Accidents can increase because of the sedative effects of benadryl. Although real life data is unavailable, it is not safe to operate a motor vehicle if one is taking it. In children it can cause paradoxical stimulation with agitation and confusion as the presenting signs.
In adults 65 and older, long-term frequent use of benadryl is associated with development of dementia and Alzheimer disease due to their anticholenergic properties. Hospitalized elderly people have an increased risk of delirium.
Other effects seen are dry mouth, low blood pressure when standing. It is also inappropriately recommended first line in food allergy action plans when epinephrine should be used instead.
Second generation antihistamines were developed to reduce the side effects and to have a longer duration of action. They have decreased penetration of the blood brain barrier and a lesser tendency to have the central nervous system. The second generation antihistamines used in the United States have superior safety and a faster onset of action.
- Loratidine (Claritin)
- Cetirizine (Zyrtec)
- Fexofenadine (Allegra)
- Levocetirizine (Xyzal)
- Desloratadine (Clarinex)
Even when the second generation antihistamines are used at much higher doses, they have not resulted in serious adverse effects. Other effects of dry mouth, nausea, urinary retention, headache and dizziness are not significantly different when compared to placebo.
There has also been a myth that benadryl has a faster onset of action and better efficacy than the newer second generation antihistamines. In fact, the opposite is true according to many studies.
So next time you ask yourself is benadryl safe to use? Consider that, 2nd generation antihistamines like Claritin, Zyrtec, or Allegra have superior safety and improved efficacy compared to benadryl. For this reason, benadryl should not be used as the treatment of choice when an antihistamine is needed.