Onfi has possible interactions with alcohol and some other drugs. Examples include opioids and hormonal birth control. Talk with your doctor to avoid potentially harmful effects from Onfi interactions.
Onfi is prescribed for seizures caused by Lennox-Gastaut syndrome (LGS) in adults and children ages 2 years and older.
An interaction occurs when one substance causes another substance to have a different effect than expected.
Onfi comes in different forms, and they have the same interactions. The forms are oral tablets and oral liquid suspension.
By learning about possible Onfi interactions, you can work with your doctor to ensure Onfi will be safe and effective for you to take. For additional information about Onfi, including details about its uses, see this Onfi overview article.
Boxed warnings
This drug has boxed warnings about the following risks. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.
Risks when taken with opioids: Taking Onfi with opioids can lead to serious side effects. These include extreme sleepiness, respiratory depression (slowed or shallow breathing), coma, and even death. Due to these risks, your doctor will only prescribe Onfi with opioids if it’s the only option available. If these medications are prescribed together, you’ll likely take the lowest effective dose for the shortest time needed. They’ll likely monitor you for signs or symptoms of sedation and respiratory depression during treatment.
Risk of misuse and addiction: Taking Onfi can increase your risk of misuse and addiction. Misuse is when you take a drug in a way other than how a doctor prescribes it. Addiction refers to feeling unable to stop taking a drug, even though it may be causing harm.
Misuse and addiction can lead to overdose and, in some cases, death. The risk is higher if you take higher doses of Onfi than recommended or if you take Onfi with certain other medications, such as opioids, alcohol, or illegal substances.
To lower the risk of misuse and addiction, take Onfi exactly as prescribed. And always check with your doctor or pharmacist before starting any new medications with Onfi.
Risk of dependence and withdrawal: Taking Onfi can lead to physical dependence. With dependence, your body needs the drug to function as usual. Dependence can lead to withdrawal if you stop taking Onfi or lower your dosage too suddenly. Withdrawal symptoms are uncomfortable side effects that can occur when you stop taking a drug your body is used to. Withdrawal can cause life threatening symptoms.
Due to these risks, your doctor will likely lower your dosage of Onfi slowly over time until it’s safe for you to stop the drug completely. You should not stop taking Onfi without talking with a doctor first.
To learn more about these warnings, talk with your doctor or pharmacist.
Show MoreBefore you start treatment with Onfi, tell your doctor and pharmacist which prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions.
To learn whether Onfi interacts with supplements, herbs, or vitamins, see the “Onfi and other interactions” section.
If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.
Here’s a table of drugs that can interact with Onfi. Keep in mind this table doesn’t include all drugs that may interact with Onfi. Some of these interactions are described in detail in “Drug interactions in depth.”
| Drug class or drug name | Drug examples | Interaction result with Onfi |
| diphenhydramine (Benadryl) | — | can increase the risk of excessive sleepiness |
| omeprazole (Prilosec) | — | can increase the risk of side effects of Onfi |
| fluconazole (Diflucan) | — | can increase the risk of side effects of Onfi |
| fluvoxamine (Luvox) | — | can increase the risk of side effects of Onfi |
| opioids | • oxycodone (Roxicodone, others) • oxycodone/acetaminophen (Percocet) • morphine (MS Contin, others) | can increase the risk of serious side effects of both drugs |
| sleep medications | • zolpidem (Ambien) • eszopiclone (Lunesta) | can increase the risk of excessive sleepiness |
| muscle relaxants | • baclofen (Lioresal) • cyclobenzaprine | can increase the risk of excessive sleepiness |
| certain antipsychotics | • haloperidol (Haldol) • chlorpromazine (Thorazine) | can increase the risk of excessive sleepiness |
| hormonal birth control | • drospirenone/ethinyl estradiol (Yasmin) • norethindrone/ethinyl estradiol/ferrous fumarate (Lo Loestrin Fe) | can make the hormonal birth control less effective |
| other benzodiazepines | • alprazolam (Xanax) • lorazepam (Ativan) | can increase the risk of excessive sleepiness |
In some cases, factors or conditions could prevent your doctor from prescribing Onfi due to the risk of harm. These are known as contraindications.
The contraindications of Onfi include:
Having had an allergic reaction to Onfi or any of its ingredients
If you’ve had an allergic reaction to Onfi or any of its ingredients, your doctor will likely not prescribe Onfi. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.
Note: Before you start treatment with Onfi, it’s important to tell your doctor if this contraindication applies to you. They can determine whether to prescribe Onfi.
If you drink alcohol, your doctor will likely recommend that you not drink it while taking Onfi. They’ll also usually advise you not to take any prescription or over-the-counter drugs that contain alcohol during Onfi treatment.
Consuming alcohol and taking Onfi may cause serious side effects, including:
- difficulty breathing
- sleepiness
- decreased awareness
- coma
The combination of alcohol and Onfi may also, in some cases, lead to death.
Plus, alcohol can raise the level of Onfi in your system. This can increase your risk of serious side effects from Onfi.
If you have concerns about avoiding alcohol while you’re taking Onfi, talk with your doctor before starting treatment.
Here’s a closer look at certain drug interactions of Onfi.
Omeprazole
Omeprazole is used to treat conditions related to excessive stomach acid. Taking Onfi with omeprazole (Prilosec) can increase the risk of side effects of Onfi. This is because omeprazole blocks an enzyme (protein) involved in breaking down Onfi in your system. If this enzyme is blocked, you may not be able to clear Onfi from your system as quickly as usual. This can lead to higher levels of Onfi in your system, which increases your risk of side effects.
Steps you or your doctor may take
Before starting omeprazole, tell your doctor you take Onfi. They may lower your dosage of Onfi. If you’re taking these drugs together and develop any new or worsening side effects, tell your doctor. They may adjust your dosage of Onfi or have you switch to an alternative acid reflux medication.
Sleep medications
Medications used for sleep work by slowing down the activity of your central nervous system (CNS). (Your CNS is made up of your brain and spinal cord.) This can cause side effects such as drowsiness. Onfi also causes drowsiness. So combining these medications can make you excessively drowsy. This can make it hard to focus, think, or react.
Here are some sleep drugs that may interact with Onfi:
- zolpidem (Ambien)
- eszopiclone (Lunesta)
- ramelteon (Rozerem)
- zaleplon (Sonata)
- doxepin
- suvorexant (Belsomra)
Steps you or your doctor may take
Tell your doctor if you take any sleep medications before taking Onfi. Due to these risks, they may suggest an alternative. If you and your doctor decide to take these medications together, you should not drive or do anything that requires concentration until you know how the combination of these drugs affects you.
Hormonal birth control
Taking Onfi with hormonal birth control can make the birth control less effective. This is because Onfi can speed up the breakdown of hormonal contraceptives in your body. This can lead to lower levels of the hormonal contraceptive in your system, which can make it less effective.
Here are some examples of hormonal contraceptives that may interact with Onfi:
- NuvaRing (etonogestrel/ethinyl estradiol)
- Beyaz (ethinyl estradiol/drospirenone/levomefolate)
- medroxyprogesterone (Depo-Provera)
- Yasmin (drospirenone/ethinyl estradiol)
- Lo Loestrin FE (norethindrone/ethinyl estradiol/ferrous fumarate)
Steps you or your doctor may take
Tell your doctor if you take hormonal birth control before you start Onfi. They may recommend that you switch to a nonhormonal form of birth control while taking Onfi and for 28 days after finishing Onfi treatment.
Onfi may have other interactions, such as with supplements, foods, vaccines, or lab tests.
Here are some potential interactions with Onfi. Keep in mind that the following information does not include all possible Onfi interactions.
Onfi interactions with supplements
It’s possible for drugs to interact with supplements such as vitamins and herbs.
Onfi interactions with herbs
There are no specific reports of herbs interacting with Onfi. However, that doesn’t mean herbal interactions won’t occur or be recognized in the future. Because of this, it’s important to check with your doctor or pharmacist before taking any of these products during Onfi treatment.
Onfi interactions with vitamins
There are no specific reports of vitamins interacting with Onfi. However, that doesn’t mean vitamin interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before taking any vitamin product with Onfi.
Onfi interactions with food
There were no reports of food interactions with Onfi. If you’d like to learn more about eating certain foods during treatment with Onfi, talk with your doctor.
Onfi interactions with vaccines
There aren’t any known interactions between Onfi and vaccines. Talk with your doctor or pharmacist to check whether you’re due for any vaccines.
Onfi interactions with lab tests
Onfi isn’t known to interact with lab tests. If you have concerns about this medication interacting with lab tests, talk with your doctor.
ONFI INTERACTION WITH CANNABIS OR CBDCannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have been specifically reported to interact with Onfi.
Using cannabis or cannabis products while taking Onfi can increase your risk of certain side effects. These include pneumonia and excessive drowsiness. It may also lead to an increase in liver enzymes, which may be a sign of liver problems.
Before you start treatment with Onfi, 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 U.S. states to varying degrees.
Certain medical conditions and other factors may increase the risk of interactions with Onfi. Before you take this drug, be sure to talk with your doctor about your health history. Onfi may not be the right treatment option if you have certain medical conditions or other factors affecting your health.
Health conditions or factors that might interact with Onfi include:
- Mental health conditions or suicidal thoughts and behaviors: Onfi may increase your risk of mood problems, depression, and suicidal thoughts and behaviors. If you have a history of mental health conditions or suicidal thoughts and behaviors, Onfi may worsen your condition.
- Kidney problems: Onfi may not be safe for you if you have severe kidney problems or are on dialysis. If you have serious kidney problems or are on dialysis, tell your doctor. They may prescribe a different medication.
- Liver problems: Onfi is cleared from your system by your liver. If you have a history of liver problems, you may not be able to clear Onfi as quickly as usual. This can cause the drug to build up in your system, which can increase your risk of side effects. Due to this risk, your doctor may prescribe a lower dosage of Onfi than usual if you have liver problems.
- Allergic reaction: If you’ve had an allergic reaction to Onfi or any of its ingredients, your doctor will likely not prescribe Onfi. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.
- Breastfeeding: It may not be safe to use Onfi while breastfeeding. The drug passes into breast milk and can cause side effects in a child who is breastfed. If you’re breastfeeding or planning to, talk with your doctor before using Onfi. They can talk with you about treatment options and ways to feed a child other than breastfeeding.
- Pregnancy: Onfi may not be safe to use while pregnant. Taking Onfi late during pregnancy can cause serious side effects in your baby. If you’re pregnant or planning to become pregnant, tell your doctor before starting Onfi. They can advise you on the right treatment plan for you.
Help is out there
If you or someone you know is in crisis and considering suicide or self-harm, please seek support:
- Call or text the 988 Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
- Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
- Not in the United States? Find a helpline in your country with Befrienders Worldwide.
- Call 911 or your local emergency services number if you feel safe to do so.
If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.
If you’re not in the same household, stay on the phone with them until help arrives.
You can take certain steps to help prevent interactions with Onfi. Your doctor and pharmacist are key resources, so reaching out to them before starting treatment is a helpful first step. For example, it’s important that you plan to do the following:
- Let them know if you drink alcohol or use cannabis.
- Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
- Create a
medication listTrusted Source , which your doctor and pharmacist can help you fill out.
It’s also important to read the Onfi label and other
If Onfi doesn’t come with paperwork, you can ask your pharmacist to print a copy. If you need help reading or understanding this information, ask your doctor or pharmacist.
You can also help prevent interactions with Onfi by taking it exactly as your doctor prescribes.
Disclaimer: Medical News Today 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.
