Key takeaways
- Vykat XR is the first medication specifically approved to manage hyperphagia (extreme hunger) in adults and some children with Prader-Willi syndrome.
- Vykar XR works by opening KATP channels in the brain and pancreas. In turn, it helps stabilize hunger signals and reduce “food noise.”
- Vykat XR is taken once daily. Treatment involves a 6 to 7-week titration process tailored to your individual weight to help ensure safety and effectiveness.
For people living with Prader-Willi syndrome (PWS), the most challenging symptom is often hyperphagia (an overwhelming, constant drive to eat that can feel impossible to satisfy).
In March 2025, Vykat XR (diazoxide choline) became the first medication specifically approved to treat this intense hunger in adults and children ages 4 and older.
Keep reading for an overview of what you need to know about Vykat XR, how it works, and what to expect during treatment.
Vykat XR is an extended-release tablet designed to help manage hyperphagia (also called polyphagia) in people with PWS.
Unlike traditional appetite suppressants, Vykat XR is a KATP channel agonist. It works by targeting specific pathways in the brain and body that are often out of balance in PWS. In turn, this helps to reduce the constant “food noise” and food-seeking behaviors that characterize the condition.
Approved use
Vykat XR is specifically approved for hyperphagia in adults and children ages 4 years and older with PWS.
In a typical person, the brain receives signals when the body has had enough to eat. With PWS, these signals are disrupted, often due to dysfunction in the hypothalamus. This leads to a state of constant hunger and a lack of satiety (feeling full).
Vykat XR contains diazoxide choline. It works by opening KATP channels, which has two primary effects:
- In the brain: It may help stabilize the hunger-regulating centers in the hypothalamus, making the drive to find food less intense.
- In the pancreas: It reduces the release of insulin. Because insulin is a hormone that can drive hunger and fat storage, managing insulin levels can help reduce hunger cravings.
Medical Perspective“For families managing PWS, it can help to check blood sugar at the same times each day, such as before meals. Keeping a simple notebook or app to track blood sugar and meals can make it easier to see patterns.”
— Alex Nguyen, PharmD, RPh, CPh
» Learn more: Blood Sugar Level Chart Based on Age
Quotes represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
Vykat XR is a once-daily oral tablet. It can be taken at any time of day, but taking it at the same time each day will help keep a steady level of Vykat XR in your system.
Taking Vykat XR as part of your morning or evening routine may also help prevent missed doses.
Tablet strengths and dosages
Vykat XR is available in three tablet strengths to allow for precise dosing: 25 milligrams (mg), 75 mg, and 150 mg.
Because the medication is tailored to an individual’s body weight in kilograms (kg), the dosage can range significantly:
- Minimum dosage: The smallest starting dose is 25 mg once daily. However, depending on your weight, your starting dose may range from 25 mg to 150 mg daily.
- Maximum dosage: The highest recommended dose is 5.8 mg/kg/day or a total of 525 mg per day, whichever is less.
Titration process
You won’t start at the full dose immediately. Because each body reacts differently, your doctor will use a weight-based titration schedule. This typically lasts about 6 to 7 weeks:
- Weeks 1 to 6: The dose is gradually increased every 2 weeks.
- Week 7 and beyond: You reach the “maintenance dose” tailored to your or your loved one’s specific weight.
Tips for taking Vykat XR
- Swallow whole: Vykat XR tablets should not be crushed, split, or chewed. Doing so ruins the drug’s “extended-release” (XR) effect, which could lead to too much medication entering the body at once.
- Consistency: Try to take it at the same time every day, with or without food.
- Missing a dose (less than 7 days): If you miss your dose fewer than 7 days, take your next dose as soon as you remember. Do not take more than one dose to make up for the missed dose.
- Missing a dose (more than 7 days): If you miss your dose for more than 7 days, contact your doctor. They may have you restart the titration process rather than continuing at your current dose.
Like all medications, Vykat XR can cause side effects. Most are manageable, but some require close monitoring by your medical team. The information below does not cover all possible interactions of Vykat XR. For a full list, see the drug’s prescribing information.
Common side effects
In clinical trials, the most frequently reported side effects included:
| Side effect | What to know |
|---|---|
| hypertrichosis (increased hair growth all over the body) | About 36% of people taking Vykat XR reported excessive body hair growth, including on the forehead, back, arms, or legs. |
| edema (swelling due to fluid retention) | About 27% of people taking Vykat XR experienced some swelling, often in the legs or ankles. |
| hyperglycemia (high blood sugar) | Because Vykat XR reduces insulin release, it can cause high blood sugar. Symptoms may include increased thirst, frequent urination, blurred vision, or fatigue. |
| rash | A small percentage of people developed a mild skin rash. |
In most cases, most side effects of Vykat XR are mild and manageable. Some may go away on their own as your body adjusts to the drug, while others may only go away if you stop taking Vykat XR.
If you experience persistent or bothersome side effects during treatment with Vykat XR, talk with your doctor or pharmacist about ways to manage. But if you’re experiencing severe side effects or believe you’re having a medical emergency, call 911 or your local emergency number right away.
Important safety information
- Blood sugar monitoring: High blood sugar is a known effect of Vykat XR. Your doctor will check your fasting glucose and HbA1c levels before you start and regularly during treatment. They can also show you how to monitor your own blood sugar levels at home. Without treatment, unmanaged high blood sugar can lead to life threatening complications like diabetic ketoacidosis.
- Fluid overload: Fluid retention is a common side effect that can sometimes lead to more serious fluid overload. While this risk is higher in people with a preexisting heart problem, it can occur in anyone. If you notice unusual swelling, rapid weight gain, or shortness of breath, report it to your doctor immediately. Fluid overload can lead to serious complications, such as pulmonary edema and heart failure.
- Allergic reaction: Doctors typically won’t prescribe Vykat XR if you have a known allergy to diazoxide or certain “water pills” (thiazide diuretics). Allergic reactions have been reported with Vykat XR, but they weren’t common in clinical trials of the drug.
Understanding your blood sugar tests
- Fasting glucose: This is a “snapshot” of your blood sugar at a single point in time, usually taken first thing in the morning before you’ve eaten.
- HbA1c: This is the “big picture” view. It measures your average blood sugar levels over the past 2 to 3 months.
Why it matters: Because Vykat XR can increase your blood sugar, regularly monitoring these levels . If your blood sugar levels are too high, your doctor may lower
» Learn more: 5 Best At-Home Diabetes Tests
Before starting Vykat XR, it’s important to tell your doctor about all medications, vitamins, and herbal supplements you’re currently taking. Some medications may increase the risk of side effects with Vykat XR or make the drug less effective.
In some cases, your doctor may need to adjust your dosage of Vykat XR or the medication. In other cases, they may not prescribe Vykat XR for your condition.
| Drug class | Examples | Interaction & recommendation |
|---|---|---|
| strong CYP1A2 inhibitors | • fluvoxamine • ciprofloxacin (Cipro) | These drugs slow down the breakdown of Vykat XR, raising levels in the body. Doctors may prescribe a lower dose of Vykat XR. |
| CYP1A2 substrates | • tizanidine • theophylline • duloxetine (Cymbalta) | Vykat XR slows the breakdown of these drugs, which can lead to toxic levels. Use together is not recommended. |
| CYP3A4 inhibitors | • itraconazole • clarithromycin | Blocks liver enzymes, potentially increasing Vykat XR levels. Doctors will monitor more closely for side effects. |
| strong CYP3A4 / moderate CYP1A2 inducers | • rifampin (Rifadin) • carbamazepine (Tegretol) | These drugs speed up the breakdown of Vykat XR, making it less effective. Use together is not recommended. |
| drugs highly bound to protein | • warfarin (Jantoven) • phenytoin (Dilantin) | Vykat XR may change how well your body absorbs these drugs. Doctors will monitor drug levels and side effects more frequently. |
| thiazides or other diuretics | • hydrochlorothiazide • furosemide | These drugs can worsen high blood sugar, high uric acid, or low blood pressure. Doctors will monitor blood sugar and blood pressure closely. |
- Comparing pharmacies: The price of Vykat XR can vary by pharmacy, so it helps to compare prices to find the lowest cost.
- Drug coupons: You may be able to find drug coupons on prescription discount websites that can reduce the cost of your medication. These coupons cannot be used with insurance copays or benefits, but the discounted price may be lower than what you would pay through insurance.
- Financial assistance: Some websites provide details about drug assistance programs, ways to make the most of your insurance coverage, and links to savings cards and other services. Two such websites are:
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While Vykat XR is not a weight-loss drug, reducing hyperphagia may lead to better management of food cravings. If Vykat XR causes you to eat less, you may lose weight as a result.
Vykat XR is FDA approved for children as young as 4 years old. The dosing is strictly weight-based to ensure it is appropriate for smaller bodies.
Vykat XR can be discontinued without tapering, but hyperphagia symptoms will likely return once the medication leaves your system. It’s important to consult your doctor before stopping any prescribed treatment. Your doctor will advise you on the risks and benefits of stopping a medication.
Vykat XR is a significant milestone in the care of those with Prader-Willi syndrome. By targeting the KATP channels in the brain, it offers a way to tone down the biological “emergency signal” of hunger that can make PWS so difficult to manage.
Success with Vykat XR relies on a partnership between you and your healthcare team. Through careful weight-based dosing and regular monitoring of blood sugar and fluid levels, this medication can be an effective way to improve quality of life with PWS.
Disclaimer: While Healthline strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses. Learn more about our approach to content integrity.