Understanding Vijoice Side Effects Before You Start Treatment

If you or your child has been prescribed Vijoice (Alpelisib) for PIK3CA-Related Overgrowth Spectrum (PROS), knowing what side effects to expect—and which ones need immediate medical attention—can make a real difference in how you manage treatment. Like all medications, Vijoice comes with potential side effects, but understanding them ahead of time helps you feel more prepared and in control.

What Is Vijoice?

Vijoice is the brand name for Alpelisib, a PI3K inhibitor manufactured by Novartis. It's the first and only FDA-approved systemic treatment for patients aged 2 and older with severe PIK3CA-Related Overgrowth Spectrum (PROS). It works by blocking the PI3K-alpha enzyme, which reduces the abnormal cell growth caused by PIK3CA gene mutations. For a deeper dive into how this medication works, see our guide on how Vijoice works: mechanism of action explained.

Common Side Effects

The following side effects are reported frequently in clinical trials and real-world use. Most are manageable and may improve over time as your body adjusts to the medication:

• Diarrhea — One of the most common side effects. Can range from mild to moderate. Staying hydrated and eating bland foods can help.
• Stomatitis (mouth sores) — Painful sores in and around the mouth. Using a soft toothbrush and avoiding spicy or acidic foods may reduce discomfort.
• Hyperglycemia (high blood sugar) — Elevated blood sugar is very common with Alpelisib. Your doctor will monitor your glucose levels regularly, especially in the first few months.
• Dry skin — Many patients experience dry, flaky, or itchy skin. Fragrance-free moisturizers applied after bathing can help.
• Eczema — Skin inflammation that may appear as red, itchy patches. Your doctor may recommend topical treatments.
• Headache — Mild to moderate headaches are reported. Over-the-counter pain relievers (approved by your doctor) usually help.
• Hair loss (alopecia) — Some patients experience thinning hair or hair loss during treatment.

Serious Side Effects: When to Call Your Doctor Immediately

While most side effects are manageable, some require urgent medical attention. Contact your doctor or go to the emergency room if you experience any of the following:

Severe Hyperglycemia

This is the most significant risk with Vijoice. In the oncology setting (where Alpelisib is used at higher doses under the brand name Piqray), severe hyperglycemia has led to life-threatening conditions including hyperglycemic hyperosmolar non-ketotic syndrome and fatal ketoacidosis. While doses for PROS are lower, the risk is still real.

Call your doctor if you notice:

• Excessive thirst or dry mouth
• Frequent urination
• Blurred vision
• Unusual fatigue or drowsiness
• Fruity-smelling breath
• Nausea or vomiting

Severe Allergic Reactions (Anaphylaxis)

Although rare, severe allergic reactions can occur. Seek emergency medical help if you experience:

• Difficulty breathing or swallowing
• Swelling of the face, lips, tongue, or throat
• Severe rash or hives
• Rapid heartbeat
• Dizziness or fainting

Severe Skin Reactions (SCAR)

Severe cutaneous adverse reactions, including Stevens-Johnson syndrome (SJS), can occur. Stop taking Vijoice and contact your doctor immediately if you notice:

• Widespread skin rash with blistering or peeling
• Sores in the mouth, eyes, or genital area
• Fever with skin changes
• Skin that looks burned

Pneumonitis (Lung Inflammation)

Vijoice can cause inflammation in the lungs. Report these symptoms promptly:

• New or worsening cough
• Shortness of breath
• Chest pain
• Difficulty breathing during normal activities

Severe Diarrhea and Dehydration

While mild diarrhea is common, severe diarrhea can lead to dehydration and acute kidney injury. Call your doctor if:

• Diarrhea doesn't improve with over-the-counter treatments
• You have more than 6 loose stools per day
• You see blood in your stool
• You feel dizzy, lightheaded, or produce very little urine

Colitis

Inflammation of the colon can occur. Watch for severe abdominal pain, bloody diarrhea, or persistent cramping.

Side Effects in Specific Populations

Children (Ages 2-17)

The most common starting dose for pediatric patients is 50 mg daily, which is lower than the adult dose. Side effects in children are similar to those in adults, but parents should watch especially closely for signs of hyperglycemia and growth changes. Regular blood sugar monitoring is critical.

Patients with Diabetes or Pre-Diabetes

If you have a history of diabetes or elevated blood sugar, you are at higher risk for severe hyperglycemia on Vijoice. Your doctor may need to adjust your diabetes medications and monitor your glucose more frequently. Make sure your prescribing specialist is aware of your full medical history.

Pregnant or Breastfeeding Patients

Vijoice can cause harm to a developing fetus. Pregnancy should be ruled out before starting treatment, and effective contraception must be used during treatment and for at least 1 week after the last dose. Breastfeeding is not recommended during Vijoice therapy and for 1 week after the final dose.

Fertility

Alpelisib may impair fertility in both males and females. Discuss fertility preservation options with your doctor before starting treatment if this is a concern.

How to Manage Common Side Effects

Here are practical tips for dealing with the most frequent side effects:

• For diarrhea: Drink plenty of fluids, eat small bland meals, and ask your doctor about anti-diarrheal medications like loperamide.
• For mouth sores: Rinse with a baking soda and salt water solution several times daily. Avoid mouthwashes containing alcohol.
• For high blood sugar: Follow your doctor's monitoring schedule. Reduce sugar and refined carbohydrate intake. Report any readings above your doctor's specified threshold.
• For dry skin and eczema: Apply fragrance-free moisturizer immediately after bathing. Use gentle, soap-free cleansers. Your doctor may prescribe topical corticosteroids for severe eczema.
• For headaches: Stay hydrated and get adequate rest. Ask your doctor which over-the-counter pain relievers are safe to use with Vijoice.
• For hair loss: Use gentle shampoos and avoid heat styling. Hair loss from Alpelisib is usually reversible after treatment ends.

Keep a symptom diary to share with your doctor at each visit. Tracking when side effects start, how severe they are, and what helps can make your appointments more productive and help your doctor fine-tune your treatment plan.

Final Thoughts

Vijoice is a groundbreaking treatment for PROS, but like any powerful medication, it requires careful monitoring. The most important thing you can do is stay in close communication with your healthcare team. Report new symptoms early, keep all monitoring appointments, and don't adjust your dose without talking to your doctor first.

If you're still learning about Vijoice, our complete guide covers everything from uses to dosing: What is Vijoice? Uses, dosage, and what you need to know. And if you're concerned about drug interactions, check out Vijoice drug interactions: what to avoid.