Can You Take Benadryl If You Have Emphysema?

The pharmacist discusses whether or not Benadryl is safe to take if you have been diagnosed with emphysema.


Why is it contraindicated to take Benadryl if you have emphysema?

Asked by Kay On Jun 18, 2018

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Jun 18, 2018

EmphysemaWhile not absolutely contraindicated, Benadryl (diphenhydramine) should be used with caution in those with respiratory disease, such as:

  • Asthma
  • COPD (Chronic obstructive pulmonary disease)
  • Emphysema

Taking Benadryl If You Have Emphysema

Antihistamines, like Benadryl (diphenhydramine), should be taken with caution in patients with emphysema due to the anticholinergic effects, which includes a strong "drying effect". The anticholinergic activity of antihistamines can cause thickened bronchial secretions in the respiratory tract, which can potentially exacerbate respiratory symptoms and cause labored breathing.

If you are looking to take an antihistamine and have been diagnosed with emphysema, it is preferable to take one with less anticholinergic activity, like the second-generation antihistamines, which include:

  • Claritin
  • Zyrtec
  • Allegra

About the Pharmacist

Dr. Adam DeRue Pharm.D

Dr. Adam DeRue is a Doctor Of Pharmacy and registered pharmacist.

About Benadryl (Diphenhydramine)

Benadryl (diphenhydramine) is a first generation, sedating antihistamine (H1-blocker) of the ethanolamine class. It is available in oral, topical, and parenteral product forms. Benadryl is well known to cause significant sedation in most individuals and is commonly used in night-time sleep aids. Benadryl also has potent "drying" effects in most patients, which is why is causes dry mouth, dry eyes and constipation. The onset of action of Benadryl is around 15-30 minutes after taking by mouth, with peak effects occurring 1 to 3 hours later. The duration of action is around 4 to 6 hours, with this being prolonged in the elderly and in those with liver disease.

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