Benadryl and Alcohol: Drug Interactions and Risks

What you will learn

• Benadryl is an over-the-counter antihistamine medication used to treat allergies.
• Diphenhydramine, the main ingredient in Benadryl, is a central nervous system depressant that can interact dangerously with alcohol.
• Combining Benadryl and alcohol can cause dangerous levels of sedation that can put you at risk of injury or adverse side effects.

If you suffer from seasonal allergies and symptoms like a runny nose, sneezing, or red, itchy eyes, Benadryl is a reliable over-the-counter (OTC) drug to relieve your symptoms. This brand-name antihistamine, diphenhydramine, is a safe option for many people. However, it does have the risk of interactions – particularly with alcohol.

Learn more about the drug interactions and risks of mixing Benadryl with alcohol and what precautions you should take.

What Is Benadryl and How Does It Work?

Benadryl is a brand-name version of the antihistamine diphenhydramine. Antihistamines interfere with the action of the compound histamine in the body, which affects your immune response. Histamines are behind the nasal congestion, itchy skin and eyes, and other symptoms from seasonal allergies or topical allergens. Antihistamines like Benadryl block the body’s response to allergens, relieving allergy symptoms.

Many people think it’s safe because Benadryl is available at most pharmacies and stores without a prescription. Benadryl is a powerful medication. However, that comes with some risks, including serious side effects if it’s combined with certain substances.

The Dangers of Mixing Alcohol and Benadryl

Benadryl is a central nervous system depressant, which slows down the activity in the central nervous system and causes drowsiness, sedation, and difficulty with physical and mental tasks that require you to be alert. Alcohol, another central nervous system depressant, does the same thing.

If you combine Benadryl and alcohol, it can slow your central nervous system activity and lead to dangerous levels of sedation.[1] This is a risk with normal doses of Benadryl and alcohol, but the risk is much higher if you misuse Benadryl.

Benadryl Misuse

Benadryl is approved to treat the symptoms of allergies, such as seasonal outdoor allergies. It’s not intended for any other purpose, but it’s common for people to misuse Benadryl as a sleep aid because of the drowsiness it causes.[2]

Alcohol is also misused to help with sleep and self-medicate insomnia. If you take them together, however, it can have the opposite effect. You can experience dizziness that affects your ability to get complete, restful sleep.

Driving on Benadryl and Alcohol

Benadryl has a warning not to drive or use any heavy machinery while you’re taking the medication. This is because of the risks of severe central nervous system depression, which can make you drowsy and slow your reaction times – a necessary component of safe driving.

According to the National Highway Traffic Safety Administration, Benadryl may have a bigger impact on your ability to stay alert and drive safely than alcohol.[3] If you combine the two, it can be extremely dangerous for you and others on the road.

Can I Have Any Alcohol with Benadryl?

It’s difficult to know how any amount of alcohol will affect you while you’re taking Benadryl. Everyone has different reactions to medications and different alcohol tolerances. One person may be extremely drowsy from one Benadryl dose, while others may feel completely alert.

If you’re not sure how the medication affects you, it’s best to avoid alcohol completely while you’re taking Benadryl. If you do have a drink or two, avoid driving or engaging in other activities that can be dangerous if your reaction times are slowed.

Additional Risk Factors for Alcohol and Benadryl Interactions

Alcohol and Benadryl are never completely safe together – there’s always a possibility of a reaction. However, certain people are at an increased risk of interactions, including:

• Older adults: Older people tend to have a lower alcohol tolerance than younger people.[4] Combining any medication with alcohol can increase the risk of serious side effects, particularly with Benadryl.
• Women: Women usually have a lower alcohol tolerance than men, leading to greater levels of sedation and confusion.[5]

Most people don’t experience serious side effects of Benadryl when taking the drug by itself and as directed. However, there have been reports of people misusing Benadryl and experiencing side effects from high doses, such as hallucinations, seizures, and trouble breathing.[6] Mixing Benadryl with alcohol significantly increases these risks.

Benadryl can worsen the symptoms of some serious medical conditions as well, including glaucoma, an enlarged prostate, and chronic obstructive pulmonary disease (COPD). These effects may be worse with alcohol.

What to Do If You Drank Alcohol with Benadryl

If you’ve accidentally mixed alcohol and Benadryl, don’t panic. Just pay attention to your symptoms and how you feel. If possible, have someone with you to watch for serious effects.

Several symptoms can occur when you mix Benadryl and alcohol, however. Seek medical attention if you experience extreme drowsiness, memory impairment, confusion, a disconnect from reality, seizures, hallucinations, or difficulty breathing.

When Can I Drink Alcohol After Taking Benadryl?

You should avoid alcohol until Benadryl has been eliminated from your system. Generally, Benadryl clears the body about two days after the last dose. Remember that several factors affect how you break down medications, including age, body mass, medical conditions, organ function, and other substances you may have taken.

Risks of Hidden Alcohol Sources

It’s easy to avoid drinking alcohol while taking Benadryl once you understand the risks, but you need to be aware of hidden alcohol sources that can cause dangerous interactions.

For example, some medications contain small amounts of alcohol, such as cough syrup and laxatives. Like any cocktail, these drugs can interact with Benadryl. Always read the labels on drugs to reduce your risk of accidental interactions.

If you’re taking multiple OTC or prescription drugs, talk to your doctor or pharmacists about any potential interactions with Benadryl.

Signs of Substance Abuse

As mentioned, Benadryl may be misused as a sleep aid. Alcohol is misused in similar ways, and combining the two is a sign of substance abuse or a heightened risk of substance abuse.

When people combine Benadryl and alcohol intentionally, it’s usually with the intent to relax. If either drug doesn’t provide these effects on its own, they may mix the two to get stronger drowsiness.

Getting Help for Abuse or Addiction to Benadryl and Alcohol

If you struggle with Benadryl or alcohol addiction – or both – it’s important to seek help before you experience serious health effects. While Benadryl is safe to stop on your own, quitting alcohol if your body has built up a tolerance and dependence can cause potentially life-threatening withdrawal symptoms.

The first step in treating alcohol abuse or addiction is medical detox. You can’t overcome alcohol withdrawal on your own, and detox provides a medical team to monitor your health, prevent complications, and minimize your withdrawal symptoms as much as possible.

Once detox is complete, it’s important to start an addiction treatment program to address the emotional, social, and psychological causes of addiction. Though treatment programs are tailored to your unique history and goals, they often include a combination of traditional counseling and behavioral therapies in an inpatient or outpatient setting.

Avoid Dangerous Interactions with Benadryl and Alcohol

If you take Benadryl for allergies, it’s crucial to avoid drinking alcohol with it. Benadryl causes high levels of sedation that are amplified by alcohol, leading to dangerous symptoms like slowed breathing and confusion. Talk to your doctor about possible drug interactions before you drink alcohol with Benadryl.

Amanda is a prolific medical content writer specializing in eating disorders and addiction treatment. She graduated Magna Cum Laude from Purdue University with a B.S. in Social Work. Read more