Benadryl (diphenhydramine) is an over-the-counter drug that’s used to treat allergies and certain other conditions. This drug can interact with other medications and some supplements. For example, Benadryl can interact with certain blood pressure medications and some antidepressants.
Benadryl is used in adults and some children to treat:
- seasonal allergies (hay fever) or other allergies
- the common cold
- itchiness and pain due to insect bites, sunburn, skin cuts, scrapes, irritation, or rashes
An interaction can occur because one substance causes another substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.
Keep reading to learn about Benadryl’s possible interactions. And for more information about Benadryl, including details about its uses, see this article.
While you’re using Benadryl, you should avoid drinking alcohol. This is because both alcohol and Benadryl may cause you to feel sleepier than usual.
Drinking alcohol while using Benadryl may also increase your risk of other side effects. These include confusion, dizziness, and a slowed breathing rate. The combination of alcohol and Benadryl can also impair your movements, such as your ability to drive.
If you’re using Benadryl, talk with your doctor about when it may be safe for you to drink alcohol.
Before you start using Benadryl, tell your doctor and pharmacist about any prescription, over-the-counter, or other medications you take. Sharing this information with them may help prevent possible interactions.
If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.
The chart below lists drugs that may interact with Benadryl. Keep in mind that this chart does not include all drugs that may interact with Benadryl. For more information about some of these interactions, see the “Drug interactions explained” section below.
| Drug group or drug name | Drug examples | Interaction result with Benadryl |
| other antihistamines | • loratadine (Claritin) • meclizine (Antivert) • hydroxyzine (Vistaril) • cetirizine (Zyrtec) • promethazine (Promethegan) | can increase the risk of side effects from Benadryl and other antihistamines |
| anticholinergic drugs | • benztropineoxybutynin (Ditropan XL) • solifenacin (Vesicare) | can increase the risk of side effects from Benadryl and anticholinergic drugs |
| antipsychotic drugs | • haloperidol (Haldol) • olanzapine (Zyprexa) • risperidone (Risperdal) • aripiprazole (Abilify) | can increase the risk of side effects from Benadryl and antipsychotic drugs |
| benzodiazepines | • diazepam (Valium) • alprazolam (Xanax) • clonazepam (Klonopin) • lorazepam (Ativan) | can increase the risk of side effects from Benadryl and benzodiazepines |
| sedative-hypnotics | • eszopiclone (Lunesta) • zolpidem (Ambien) • suvorexant (Belsomra) | can increase the risk of side effects from Benadryl and sedative-hypnotics |
| opioids | • fentanyl (Subsys) • oxycodone (Roxicodone) • buprenorphine (Butrans) • buprenorphine and naloxone (Suboxone) • hydrocodone (Hysingla ER) | can increase the risk of side effects from Benadryl and opioids |
| selective serotonin reuptake inhibitors (SSRIs) | • paroxetine (Paxil) • sertraline (Zoloft) • citalopram (Celexa) • escitalopram (Lexapro) | can increase the risk of side effects from Benadryl and SSRIs |
| monoamine oxidase inhibitors (MAOIs) | • isocarboxazid (Marplan) • phenelzine (Nardil) • selegiline (Emsam) • methylene blue (ProvayBlue) | can increase the risk of side effects from Benadryl and MAOIs |
| tricyclic antidepressants (TCAs) | • doxepin (Zonalon) • desipramine (Norpramin) • nortriptyline (Pamelor) • amitriptyline | can increase the risk of side effects from Benadryl and TCAs |
| serotonin-norepinephrine reuptake inhibitors (SNRIs) | • duloxetine (Cymbalta) • venlafaxine (Effexor XR) • desvenlafaxine (Pristiq) | can increase the risk of side effects from Benadryl and SNRIs |
| metoprolol succinate (Toprol-XL) or metoprolol tartrate (Lopressor) | — | can increase the risk of side effects from metoprolol succinate or metoprolol tartrate |
| gabapentin (Neurontin) | — | can increase the risk of side effects from Benadryl and gabapentin |
| trazodone | — | can increase the risk of side effects from Benadryl and trazodone |
Learn more about certain drug interactions that can occur with Benadryl.
Interaction with the blood pressure medications metoprolol succinate (Toprol-XL) and metoprolol tartrate (Lopressor)
Benadryl can interact with metoprolol succinate (Toprol-XL) and metoprolol tartrate (Lopressor), as described below. Metoprolol succinate and metoprolol tartrate are used to treat high blood pressure and certain other conditions.
| What could happen | What you can do |
| Benadryl may cause an increase in the amount of metoprolol in your body. This, in turn, can increase the risk of side effects from metoprolol, including slow heart rate and low blood pressure. | If you’re going to use Benadryl during treatment for high blood pressure, tell your doctor. They may recommend that you take a lower dose of metoprolol tartrate or metoprolol succinate to prevent possible side effects. |
Interaction with other antihistamines
Benadryl can interact with other antihistamines, as described below.
| What could happen | Examples of antihistamines | What you can do |
| Benadryl can increase your risk of side effects from other antihistamines. Taking more than one form of Benadryl may also increase your risk of side effects. | • loratadine (Claritin) • meclizine (Antivert) • hydroxyzine (Vistaril) • cetirizine (Zyrtec) • promethazine (Promethegan) | Due to the risk of increased side effects, your doctor may recommend that you avoid other antihistamines when you’re using Benadryl. This includes other Benadryl products. |
Interaction with trazodone
Trazodone is an antidepressant drug that may interact with Benadryl, as described below.
| What could happen | What you can do |
| Taking Benadryl with trazodone can increase your risk of side effects from either drug, such as feeling drowsy and less alert. | Tell your doctor if you’re taking trazodone and Benadryl. They may want to monitor you for side effects. |
Benadryl may have other interactions. They could occur with supplements, foods, or vaccines, to name a few examples. See below for details.
Does Benadryl interact with supplements?
Before you start using Benadryl, talk with your doctor and pharmacist about any supplements, herbs, and vitamins you take. Sharing this information with them may help you avoid possible interactions.
Benadryl interactions with supplements
Benadryl may interact with melatonin, a supplement often used as a sleep aid. Both melatonin and Benadryl can cause drowsiness or sleepiness. Using them together may make you even more drowsy than usual.
If you’re using Benadryl, talk with your doctor to see if it may be safe to take melatonin.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Benadryl and herbs
There are currently no reports of Benadryl interacting with herbs. But this doesn’t mean that interactions with herbs won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while using Benadryl.
Benadryl and vitamins
There are currently no reports of Benadryl interacting with vitamins. But this doesn’t mean that vitamin interactions won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while using Benadryl.
Does Benadryl interact with food?
There are currently no reports of Benadryl interacting with food. If you have questions about eating certain foods during your treatment with Benadryl, talk with your doctor.
Does Benadryl interact with vaccines?
Benadryl isn’t known to interact with any vaccines.
If you need a vaccine, tell your doctor or pharmacist what medications you take. They can let you know if it’s safe to get the vaccine.
Does Benadryl interact with lab tests?
Benadryl isn’t known to interact with lab tests.
If you’re concerned about your medications interacting with your lab test, talk with your doctor.
Does Benadryl interact with cannabis or CBD?Cannabis (commonly called marijuana) and cannabis products, such as cannabidiol (CBD), have not been specifically reported to interact with Benadryl.
Before you start treatment with Benadryl, tell your doctor and pharmacist if you use cannabis. By sharing this information with them, you may help prevent possible interactions.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Certain medical conditions or other health factors may raise the risk of interactions with Benadryl. Before using Benadryl, talk with your doctor about your health history. They’ll determine whether Benadryl is right for you.
Health conditions or other factors that might interact with Benadryl include:
- Breathing issues. If you have a condition that causes breathing issues, such as asthma or bronchitis, tell your doctor before using Benadryl. This medication can dry your mouth and throat. As a result, mucus in your throat may become thicker than usual, which can make it harder for you to breathe. Your doctor can determine if Benadryl is safe for you to use.
- Glaucoma. Benadryl can worsen symptoms of glaucoma, such as headache. Before you start treatment with Benadryl, tell your doctor if you have glaucoma. Your doctor will likely recommend that you take a different medication than Benadryl.
- Bladder or prostate problems. Benadryl can cause trouble urinating. Your risk of this side effect is higher If you have a bladder or prostate problem that causes trouble urinating. An example is an enlarged prostate. Before starting treatment with Benadryl, tell your doctor about any bladder or prostate problems. Your doctor can determine if it’s safe for you to use Benadryl.
- Dementia or memory problems. Benadryl can increase the risk of dementia or other memory problems. If you already have dementia, you may have an increased risk of these side effects. Because of this risk, your doctor may recommend a different treatment option for you.
- High blood pressure or heart problems. In rare cases, Benadryl may cause heart problems. This can include low blood pressure or a rapid heart rate. If you have certain heart problems or take medication for high blood pressure, you may be at increased risk of these side effects. Your doctor can determine if it’s safe for you to use Benadryl.
- Liver problems. Benadryl is broken down in your body by your liver. If you have liver problems, your body may have trouble breaking down Benadryl. This may cause an increased risk of side effects. Before starting treatment with Benadryl, tell your doctor about any liver problems that you have.
- Age. If you are age 65 years or older, you may have an increased risk of side effects with Benadryl. Due to this risk, your doctor may recommend a different medication for your condition.
- Pregnancy. Benadryl is likely safe to use during pregnancy. But before taking any medication during pregnancy, be sure to talk with your doctor. They will discuss the risks and benefits of taking specific medications during this time.
- Breastfeeding. If you’re breastfeeding, talk with your doctor before using Benadryl. The drug passes into breast milk, so it may cause drowsiness in a child who is breastfeeding. Due to this, your doctor may recommend a different antihistamine, such as loratadine (Claritin), to take during this time.
- Allergic reaction. If you’ve had an allergic reaction to Benadryl or any of its ingredients, your doctor will likely not prescribe this medication. You can ask them about other treatments that may be better choices for you.
Find answers below to some frequently asked questions about Benadryl and possible interactions.
Can I take other over-the-counter medications with Benadryl?
It depends on the over-the-counter (OTC) medication that you’d like to take. You should not take any other antihistamines, including other forms of Benadryl, while you’re using Benadryl.
But other OTC medications may be safe to take with Benadryl. Examples of OTC drugs that don’t have known interactions with Benadryl include:
- acetaminophen (Tylenol)
- ibuprofen (Advil)
- fluticasone (Flonase)
- guaifenesin (Robitussin)
If you’d like to take an OTC medication with Benadryl, talk with your doctor or pharmacist. They can discuss with you whether the combination is safe.
Is it safe to take Viagra with Benadryl?
Yes, it’s likely safe to take Viagra with Benadryl. Viagra is a medication that can be used to treat erectile dysfunction. There aren’t any reported interactions between the two medications.
If you have concerns about taking Viagra with Benadryl, talk with your doctor or pharmacist.
If I’m taking an L-theanine supplement, is it safe to use Benadryl?
Yes, it’s likely safe to use Benadryl if you take an L-theanine supplement. L-theanine is a supplement that people use for certain mood disorders, such as anxiety.
If you’re taking L-theanine, talk with your doctor or pharmacist about any other medications that you take. This can help them determine if there may be any interactions between the drugs you’re taking.
Taking certain steps can help you avoid interactions with Benadryl. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:
- Whether you consume alcohol or use cannabis.
- Other medications you take, as well as any vitamins, supplements, and herbs. Your doctor or pharmacist can help you fill out a
medication list . - What to do if you start taking a new drug during your Benadryl treatment.
It’s also important to read Benadryl’s label and other paperwork that comes with the drug. You may see colored stickers on the label that describe interactions. And the paperwork (sometimes called the
Using Benadryl exactly as prescribed can also help prevent interactions.
If you still have questions about Benadryl and its possible interactions, talk with your doctor.
Questions you may want to ask your doctor include:
- Do other drugs that could treat my condition have similar interactions?
- Does my risk of interactions depend on my dosage of Benadryl?
- Could I still use Benadryl even if it interacts with my health conditions?
To learn more about Benadryl, see these articles:
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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.