Litfulo (ritlecitinib) is a prescription oral capsule that’s used to treat severe alopecia areata. This drug can interact with medications and some supplements. For example, Litfulo can interact with caffeine and St. John’s wort.
Litfulo is used in adults and children ages 12 years and older to treat severe alopecia areata. Its active ingredient is ritlecitinib.
It’s important to note that Litfulo is not recommended for use with other medications in its drug group. The drug group is Janus kinase (JAK) inhibitors. Litfulo is also not recommended for use with strong immunosuppressants (medications that suppress the immune system).
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 Litfulo’s possible interactions. And for more information about Litfulo, including details about its uses, see this article.
Before you start taking Litfulo, tell your doctor and pharmacist about any prescription, over-the-counter, or other drugs you take. Sharing this information with them may help prevent possible interactions. (To learn whether Litfulo interacts with herbs or vitamins and supplements, see the “Are there other interactions with Litfulo?” section below.)
If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.
The table below lists drugs that may interact with Litfulo. Keep in mind that this table does not include all drugs that may interact with Litfulo. For more information about these interactions, see the “Drug interactions explained” section below.
| Drug type | Drug examples | What can happen |
|---|---|---|
| drugs affected by how Litfulo breaks down in your body | • midazolam (Nayzilam) • clozapine (Clozaril) | can increase the risk of side effects from these other drugs |
| drugs that affect how Litfulo breaks down in your body | • rifampin (Rifadin) • carbamazepine (Tegretol) | can make Litfulo less effective |
Certain health conditions or other factors could raise your risk of harm if you take Litfulo. In such cases, your doctor may not prescribe Litfulo for you. These are known as contraindications. Litfulo has the following contraindication:
- If you’ve had an allergic reaction: If you’ve had an allergic reaction to Litfulo or any of its ingredients, your doctor likely won’t prescribe Litfulo for you. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better options for you.
Before you start taking Litfulo, talk with your doctor if the factor above applies to you. Your doctor can determine whether Litfulo is safe for you to take.
Litfulo is not known to interact with alcohol. But Litfulo and alcohol can cause some similar side effects, such as headache and dizziness. So you may be more likely to experience these side effects if you drink alcohol during your Litfulo treatment.
If you have questions about consuming alcohol while taking Litfulo, talk with your doctor or pharmacist.
Learn more about certain drug interactions that can occur with Litfulo.
Interaction with drugs affected by how Litfulo breaks down in your body
The way Litfulo breaks down in your body (metabolizes) can affect certain drugs. Specifically, it can cause increased levels of these other medications in your body.
Examples of other drugs affected by this breakdown of Litfulo in your body are:
- midazolam (Nayzilam)
- clozapine (Clozaril)
What could happen
Increased drug levels caused by how Litfulo breaks down in your body can increase the risk of the other drug’s side effects.
What you can do
Talk with your doctor about any prescriptions, supplements, and over-the-counter medications you take before starting Litfulo. They’ll be able to check for possible drug interactions. Your doctor may adjust your Litfulo dosage if you do take drugs that interact with Litfulo.
Interaction with drugs that affect how Litfulo breaks down in your body
Certain medications can affect how Litfulo breaks down (metabolizes) in your body. This can decrease the level of Litfulo in your body.
Examples of drugs that affect how Litfulo breaks down in your body are:
- rifampin (Rifadin)
- carbamazepine (Tegretol)
What could happen
Decreased levels of Litfulo in your body can cause Litfulo not to work as well.
What you can do
Talk with your doctor about any prescriptions, supplements, and over-the-counter medications you take before starting Litfulo. They’ll be able to check for possible drug interactions. Your doctor may adjust your Litfulo dosage if you do take drugs that interact with Litfulo.
Litfulo may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that the information below does not include all other interactions possible with Litfulo.
Does Litfulo interact with supplements?
Before you start taking Litfulo, talk with your doctor and pharmacist about any herbs or vitamins and supplements you take. Sharing this information with them may help you avoid possible interactions.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Litfulo interactions with herbs
Litfulo can interact with St. John’s wort, an herbal supplement taken to ease symptoms of depression and other conditions. Your doctor may recommend you avoid this supplement while taking Litfulo.
Talk with your doctor if you have questions about taking St. John’s wort with Litfulo.
Litfulo and vitamins
There are currently no reports of Litfulo 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 taking Litfulo.
Does Litfulo interact with food?
Litfulo can increase side effects of caffeine when they’re taken together. These side effects can include dizziness and headaches. Examples of beverages containing caffeine include:
- sodas
- tea
- coffee
- energy drinks
You may want to consider limiting the amount of caffeinated beverages you consume while taking Litfulo.
Talk with your doctor if you’d like to learn more about consuming caffeine while taking Litfulo.
Does Litfulo interact with vaccines?
You should not receive live vaccines during or immediately before your Litfulo treatment. (Live vaccines contain weakened versions of the bacteria or virus that they’re meant to protect against.) Examples of live vaccines include:
Your doctor may recommend certain vaccines prior to starting Litfulo. If you need to receive a vaccine during treatment, talk with your doctor first. They can discuss whether it’s safe to do so.
Does Litfulo interact with lab tests?
There are currently no reports of Litfulo interacting with lab tests. If you have questions about having certain lab tests during treatment with Litfulo, talk with the healthcare professional ordering the test.
Does Litfulo interact with cannabis or CBD?There are currently no reports of Litfulo interacting with cannabis (commonly called marijuana) or cannabis products such as cannabidiol (CBD). But Litfulo affects the enzymes that cannabis uses to break down in the body. This may increase cannabis levels in your body. And higher levels of cannabis increase your risk of experiencing side effects from it.
Before you start treatment with Litfulo, 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 Litfulo. Before taking Litfulo, talk with your doctor about your health history. They’ll determine whether Litfulo is right for you.
Health conditions or other factors that might interact with Litfulo include:
Infection: Litfulo has a boxed warning for serious infections. Litfulo can increase your risk of developing serious infections. These include appendicitis, pneumonia, sepsis, COVID-19, shingles, and tuberculosis (TB). In some cases, these infections can be life threatening. For further information, see the boxed warnings section above.
Cancer: Litfulo has a boxed warning for cancer risk. This includes lung cancer, lymphoma, and skin cancer. This cancer risk is higher if you currently or previously smoked. For further information, see the boxed warnings section above.
Heart problems: Litfulo has a boxed warning for increased risk of heart problems. Examples include heart attack and stroke. This risk is higher if you are age 50 years or older with at least one risk factor for heart disease. Risk factors include currently smoking or a history of smoking. For further information, see the boxed warnings section above.
Blood clots: Litfulo has a boxed warning for risk of blood clots, including pulmonary embolism and deep vein thrombosis. These blood clots can be life threatening. This risk is higher if you are age 50 years or older with at least one risk factor for heart disease. For further information, see the boxed warnings section above.
Liver problems: Litfulo can increase your liver enzymes. Your doctor will check your liver enzymes before you start Litfulo treatment. Before taking Litfulo, be sure to talk with your doctor if you have any liver problems.
Low platelet or white blood cell counts: Litfulo can decrease your platelet and white blood cell counts. Your doctor will check your white blood cell and platelet counts before you start Litfulo. Be sure to talk with your doctor if you have any medical history concerning low platelet and white blood cell counts.
Pregnancy: It’s not known whether Litfulo is safe to take during pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor before taking Litfulo.
If you do take Litfulo while pregnant, consider enrolling in the drug’s pregnancy registry. This registry collects details about pregnancy issues reported with Litfulo. To learn more, call 877-390-2940 or talk with your doctor.
Breastfeeding: No data is available on whether Litfulo is present in human milk. Similarly, no data is available about the effects of Litfulo on a child who’s breastfed or the drug’s effects on milk production. The drugmaker recommends avoiding taking Litfulo while breastfeeding and for about 14 hours after the last dose. This is due to the risk of developing serious side effects from the drug. If you’re breastfeeding or planning to breastfeed, talk with your doctor about your options.
Allergic reaction: If you’ve had an allergic reaction to Litfulo or any of its ingredients, your doctor likely won’t prescribe Litfulo. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.
Taking certain steps can help you avoid interactions with Litfulo. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:
- whether you drink alcohol or use cannabis
- other medications you take, as well as any vitamins, supplements, and herbs (they can also help you fill out a
medication list ) - what to do if you start taking a new drug during your Litfulo treatment
It’s also important to understand Litfulo’s
If you have difficulty reading or understanding this information, your doctor or pharmacist can help.
Taking Litfulo exactly as prescribed also can help prevent interactions.
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.