Medical Providers:
Dr. Michael Vines, MD
Alex Spritzer, FNP, CARN-AP, PMHNP
Clinical Providers:
Natalie Foster, LPC-S, MS
Last Updated: March 7, 2024
Mixing medications with alcohol can lead to serious health risks, and one particularly concerning combination is Benadryl and alcohol. Benadryl, known generically as diphenhydramine, is an antihistamine often used to treat allergy symptoms. However, its sedating effects may become stronger when taken with alcohol, increasing the likelihood of harmful reactions and unwanted side effects.
Benadryl (diphenhydramine) is a widely used over-the-counter antihistamine that helps relieve symptoms like sneezing, runny nose, itchy or watery eyes, and skin irritation caused by allergies, hay fever, or the common cold. Because it can cause drowsiness, it’s also sometimes taken as a short-term sleep aid. In some cases, it may be used to ease symptoms of an overactive bladder.
Benadryl is available in several forms, including tablets, liqui-gels, cough syrups, and topical preparations such as creams, gels, or sprays.
It works by blocking histamine, a chemical your body releases during an allergic reaction. Normally, histamine attaches to receptors in the body and triggers symptoms like swelling, itching, and increased mucus production. Diphenhydramine competes for those same receptors, reducing or preventing the effects of histamine and helping to relieve allergy symptoms.
Benadryl is not typically classified as an addictive drug in the same way as opioids or benzodiazepines. However, some people may come to rely on its sedating effects, especially if it’s used frequently for sleep. This can lead to psychological dependence and patterns of misuse over time.
With regular or high-dose use, the body may also develop tolerance, meaning the same dose becomes less effective. In some cases, stopping suddenly after prolonged use can cause mild withdrawal-like symptoms such as restlessness, irritability, or sleep disturbances.
For these reasons, it’s important to use diphenhydramine only as directed by a healthcare professional or according to the product label, and to stay aware of the risks associated with frequent or long-term use.
Benadryl is generally safe when used as directed, but like most medications, it can cause side effects. These effects are usually mild but may become more pronounced when combined with alcohol.
Common side effects include:
Less common side effects include:
Rare but serious side effects include:
If any severe symptoms occur, seek medical attention immediately.
Benadryl long-term use may have negative effects on brain health. Research has suggested a possible link between extended use and an increased risk of dementia, particularly in older adults. Benadryl is part of a group of drugs called anticholinergics, which can interfere with acetylcholine, a brain chemical involved in memory and learning.
Long-term use may also be associated with cognitive decline, which refers to a gradual worsening of mental functions such as thinking, reasoning, and problem-solving.
It is important to note that these findings reflect potential risks rather than proven direct cause-and-effect. More research is still needed to fully understand long-term effects on the brain. The concerns appear stronger in older adults and in people who already have cognitive impairment.
Benadryl effects can vary depending on factors like metabolism and dosage. It usually begins working within 15 to 30 minutes, though this may differ based on the formulation.
Its effects typically last about 4 to 6 hours, but the drug can remain in the body for a longer period after that.
Mixing Benadryl and alcohol can increase sedation because both are central nervous system (CNS) depressants. This can intensify effects like drowsiness, dizziness, and impaired coordination and thinking.
Both substances may also contribute to dehydration, and using them together can increase the risk of dehydration-related side effects.
Combining them can also raise the risk of accidents and injuries due to reduced alertness, making tasks like driving or operating machinery especially dangerous.
In the pursuit of relief or relaxation, some individuals may be tempted to increase their Benadryl dosage. However, exceeding the recommended dose can lead to overdose. Taking excessive amounts, especially when combined with alcohol, can further increase this risk. Some data from the Centers for Disease Control and Prevention has noted that a portion of overdose deaths in recent years involved antihistamines.
Symptoms of diphenhydramine overdose include:
Overdosing is a medical emergency and requires immediate care. If someone shows these symptoms, seek emergency medical attention right away.
If you or someone you know is struggling with dependence on Benadryl and/or alcohol, it is important to seek help from a qualified healthcare professional or addiction specialist. Treatment may include counseling, behavioral therapies, and support groups tailored to individual needs.
A medical or mental health professional can help assess the situation and recommend appropriate care options. Early support can make recovery safer and more effective.
