A lot of pink medicine pills - Image

Overview

Benadryl (diphenhydramine) is a "first-generation" antihistamine, commonly used to prevent allergy symptoms and for the treatment of certain allergic reactions.

"First-generation" antihistamines are known for their sedative properties, which is why they are often used in over the counter sleep aids. Diphenhydramine (the active ingredient in Benadryl) is used in a variety of products including Tylenol PM and ZzzQuil.

Benadryl is not known to cause physical dependence and, for most individuals, does not need to be tapered.

I discuss this more in the sections below.


Is Benadryl Addictive?

Benadryl (diphenhydramine), for the vast majority of individuals, is not known to cause physical dependence.

It has been reported, however, to cause a psychological dependence in some. While there are cases of misuse and abuse, withdrawal symptoms from Benadryl are rare, even with long term use.

Nevertheless, Benadryl has strong anticholinergic effects, and there have been reports of 'anticholinergic withdrawal' in some individuals taking Benadryl for extended periods of time. Potential symptoms include:

  • Muscle spasm/tightness
  • Increased body temperature
  • Increased blood pressure
  • Incontinence
  • Anxiety symptoms
  • Sweating

Reports of withdrawal symptoms are uncommon and are generally published in case reports and not large review studies.

The FDA allows Benadryl to be classified as 'non-habit forming'.

However, As Benadryl may mask symptoms or otherwise hide medical issues contributing to insomnia, it can certainly be perceived as "habit-forming" or necessary since stopping the medication can result in the return of sleep problems.


Tapering Benadryl

As Benadryl doesn't typically cause physical dependence, for most individuals, it is not necessary to taper the medication.

If you are experiencing any of the anticholinergic withdrawal symptoms mentioned above, it would be prudent to discuss a proper course of action with your doctor.

They may recommend a taper in certain situations or they may recommend other medications to mitigate the effects you may experience.

If you are recommended to taper Benadryl, there is no specific guidance on how to appropriately do this.

As a general rule of thumb, medications with anticholinergic effects that are tapered should be done over at least a 7 day period of time.


Benadryl Use In Older Adults

While not contraindicated, Benadryl should be used cautiously in geriatric individuals as they are thought to be more susceptible to the anticholinergic effects of the drug. In fact, unless using Benadryl for allergic reactions, its use is not recommended according to the Beers List since it has strong anticholinergic effects.

The Beers list notes an increased risk of side effects using anticholinergic drugs (like Benadryl) in the elderly, including:

  • Dry Mouth
  • Confusion
  • Increased risk of falls
  • Constipation
  • Worsening dementia

In addition, according to the OBRA (Omnibus Budget Reconciliation Act) guidelines, all cough, cold, and allergy medications should be used only for a limited duration (less than 14 days) unless no other alternative treatments are available. Topical Benadryl products are considered safe.


Summary

  • Benadryl (diphenhydramine), a 'first-generation antihistamine', generally does not require tapering.
  • Withdrawal symptoms after long-term use are rare (but not unheard of).

  • References
    1. OBRA regulations and the use of psychotropic drugs in long-term care facilities: impact and implications for geropsychiatric care. PubMed
    2. Beers Criteria Medication List. DCRI
    3. Unbearable Pruritus After Withdrawal of (Levo)cetirizine. PubMed
    4. Effects of discontinuing anticholinergic treatment on movement disorders, cognition and psychopathology in patients with schizophrenia. PubMed
    5. Potential adverse effects of discontinuing psychotropic drugs. Part 1: Adrenergic, cholinergic, and histamine drugs. PubMed
    6. Chronic diphenhydramine abuse and withdrawal. Neurology
    7. Assessment of Abuse Potential of Drugs. FDA
    8. Hazards of antihistamine dependence in psychiatric patients: a case report. PubMed
    9. Severe Diphenhydramine Dependence and Withdrawal: Case Report. Taylor And Francis
    10. The Importance of Taking a History of Over-the-Counter Medication Use: A Brief Review and Case Illustration of “PRN” Antihistamine Dependence in a Hospitalized Adolescent. PubMed