Promacta Side Effects: What to Expect & How to Manage Them

Understanding Promacta Side Effects

If you’ve been prescribed Promacta (eltrombopag) for chronic immune thrombocytopenia (ITP), severe aplastic anemia, or hepatitis C-related thrombocytopenia, you may be wondering what side effects to expect. Understanding potential side effects—and knowing how to manage them—can help you feel more confident about your treatment.

This guide covers common and serious Promacta side effects, practical tips for managing them, and when you should contact your healthcare provider.

Have questions about Promacta side effects?  Call (917) 830-2525 or toll-free (800) 496-6111. Need help affording your Promacta? Learn about copay assistance options.

How Promacta Works

Understanding how Promacta works can help you understand why certain side effects occur.

According to the FDA, Promacta (eltrombopag) is a thrombopoietin receptor agonist. It works by mimicking a natural hormone called thrombopoietin (TPO), which signals your bone marrow to produce more platelets. Platelets are blood cells that help your blood clot and prevent bleeding.

Because Promacta stimulates platelet production, some side effects are related to this mechanism—such as the potential for blood clots if platelet counts become too high. Other side effects, like liver problems, are related to how the medication is processed in your body.

Common Promacta Side Effects

Most people taking Promacta experience some side effects, especially when first starting treatment. According to the prescribing information, common side effects vary depending on the condition being treated.

Common Side Effects in Adults with ITP

• Nausea
• Diarrhea
• Upper respiratory tract infection
• Vomiting
• Muscle aches (myalgia)
• Urinary tract infection
• Pain or inflammation in the throat (oropharyngeal pain)
• Abnormal liver function tests
• Back pain
• Flu-like symptoms (influenza)
• Tingling or numbness (paresthesia)

Common Side Effects in Children with ITP

• Upper respiratory tract infection (runny nose, stuffy nose, sneezing)
• Pain or swelling in the nose or throat (nasopharyngitis)

Common Side Effects in Patients with Hepatitis C

• Anemia (low red blood cells)
• Fever (pyrexia)
• Fatigue
• Headache
• Nausea
• Diarrhea
• Decreased appetite
• Flu-like illness
• Weakness (asthenia)
• Trouble sleeping (insomnia)
• Cough
• Itching (pruritus)
• Chills
• Muscle aches (myalgia)
• Hair loss (alopecia)
• Swelling in the extremities (peripheral edema)

Common Side Effects in Patients with Severe Aplastic Anemia

• Nausea
• Fatigue
• Cough
• Diarrhea
• Headache
• Abdominal pain
• Bruising (ecchymosis)
• Shortness of breath (dyspnea)
• Skin discoloration

Many of these common side effects improve over time as your body adjusts to the medication. Talk to your healthcare provider if any side effect becomes bothersome or doesn’t go away.

Serious Promacta Side Effects

While most Promacta side effects are manageable, some can be serious. Promacta carries a boxed warning—the FDA’s most serious warning—about the risk of liver problems in patients with hepatitis C.

Liver Problems (Hepatotoxicity)

According to the National Library of Medicine, Promacta may cause severe and potentially life-threatening liver problems. Your healthcare provider will monitor your liver function with blood tests before and during treatment.

Signs of liver problems to watch for:

• Yellowing of the skin or eyes (jaundice)
• Unusual darkening of the urine
• Unusual tiredness
• Right upper stomach area pain
• Confusion
• Swelling of the stomach area (ascites)

Get Inmediate Copay Assistance

917-830-2525

Blood Clots (Thrombosis)

Because Promacta increases platelet production, it can increase the risk of blood clots—especially if platelet counts become too high. Blood clots can form in arteries or veins and can be life-threatening.

Types of blood clots that may occur:

• Deep vein thrombosis (DVT) – blood clot in the legs
• Pulmonary embolism – blood clot in the lungs
• Portal vein thrombosis – blood clot in the liver
• Stroke or transient ischemic attack (TIA)

Signs of blood clots to watch for:

• Swelling, pain, or tenderness in your leg
• Leg pain or tenderness when walking
• Increased warmth in the area of swelling or pain
• Red or discolored skin
• Sudden shortness of breath
• Chest pain (may worsen with deep breathing)
• Sudden confusion, trouble speaking, or vision changes

Cataracts

Promacta may cause new cataracts or worsen existing cataracts. Cataracts occur when the lens of your eye becomes cloudy, affecting your vision. Your healthcare provider may recommend eye exams before and during treatment.

Signs of cataracts to watch for:

• Blurry or cloudy vision
• Difficulty seeing at night
• Sensitivity to light and glare
• Seeing “halos” around lights
• Fading or yellowing of colors

Risk of Worsening Blood Cancers

Promacta is not approved for use in patients with myelodysplastic syndrome (MDS). In patients with MDS, Promacta could cause the condition to worsen and potentially develop into acute myeloid leukemia (AML), a type of blood cancer.

Tips for Managing Promacta Side Effects

Many Promacta side effects can be managed with practical strategies. Here are some tips that may help:

Managing Nausea and Stomach Upset

• Take Promacta on an empty stomach (1 hour before or 2 hours after a meal) as directed
• Avoid spicy, fatty, or heavy foods around the time you take your medication
• Eat smaller, more frequent meals throughout the day
• Stay hydrated with clear fluids
• Talk to your healthcare provider if nausea persists—they may have additional recommendations

Managing Diarrhea

• Stay well hydrated to replace lost fluids
• Avoid caffeine, alcohol, and high-fiber foods until symptoms improve
• Eat bland foods like bananas, rice, applesauce, and toast (BRAT diet)
• Contact your healthcare provider if diarrhea is severe or lasts more than a few days

Managing Fatigue

• Get plenty of rest and prioritize sleep
• Take short naps if needed, but avoid long naps that interfere with nighttime sleep
• Stay physically active with light exercise as tolerated (with your doctor’s approval)
• Ask for help with daily tasks when needed

Managing Headache

• Stay hydrated throughout the day
• Get adequate rest
• Ask your healthcare provider about appropriate over-the-counter pain relievers
• Contact your doctor if headaches are severe or sudden

Managing Upper Respiratory Symptoms

• Use a humidifier to add moisture to the air
• Stay hydrated with warm liquids
• Use saline nasal spray as needed
• Contact your healthcare provider if symptoms worsen or you develop a fever

When to Call Your Doctor

While many side effects are manageable at home, some require prompt medical attention. Contact your healthcare provider if you experience:

• Signs of liver problems (yellowing skin/eyes, dark urine, right upper stomach pain)
• Signs of blood clots (leg swelling/pain, sudden shortness of breath, chest pain)
• Vision changes (blurry vision, seeing halos, eye pain)
• Unusual bleeding or bruising that worsens
• Fever or signs of infection
• Severe or persistent nausea, vomiting, or diarrhea
• Any side effect that concerns you or doesn’t improve

Your QuickRx pharmacist is also available to answer questions about your medication and help you determine if a side effect needs medical attention.

Required Monitoring While Taking Promacta

Because of the potential for serious side effects, regular monitoring is essential while taking Promacta. Your healthcare provider will order tests to ensure your safety.

Blood Tests

• Platelet counts: Monitored weekly until stable, then monthly to ensure levels stay in the target range
• Complete blood count (CBC): Monitors overall blood cell levels
• Liver function tests (ALT, AST, bilirubin): Checked before starting, every 2 weeks during dose adjustment, and monthly once stable

Eye Exams

• Baseline eye exam before starting treatment
• Regular eye exams during treatment to monitor for cataracts

Need Promacta Copay Assistance?

Start Your Application

After Stopping Promacta

When you stop taking Promacta, your platelet counts may drop lower than they were before treatment—which can increase bleeding risk. Your healthcare provider will monitor your blood counts weekly for at least 4 weeks after stopping treatment.

Important Drug and Food Interactions

Promacta interacts with certain medications and foods, which can affect how well it works. According to the Mayo Clinic, these interactions are important to understand:

Foods to Avoid Around Dosing Time

Promacta binds to certain minerals, which reduces how much medication your body absorbs. Avoid these foods within 4 hours of taking Promacta:

• Dairy products (milk, cheese, yogurt)
• Calcium-fortified juices
• Foods high in calcium, iron, magnesium, aluminum, selenium, or zinc

Medications to Take Separately

Take Promacta at least 2 hours before or 4 hours after:

• Antacids containing aluminum, calcium, or magnesium
• Mineral supplements (iron, calcium, zinc, selenium, magnesium)
• Multivitamins with minerals

Other Medication Interactions

Tell your healthcare provider about all medications you take, including prescription drugs, over-the-counter medicines, vitamins, and supplements. Promacta may interact with certain medications, including some statins used for cholesterol.

Affording Your Promacta Treatment

Managing side effects is easier when you can consistently afford your medication. QuickRx Specialty Pharmacy helps patients access Promacta copay assistance programs that can reduce out-of-pocket costs significantly—sometimes to as little as $0-$50 per month.

How QuickRx Helps

• Free copay assistance enrollment: We identify all programs you qualify for and handle the paperwork
• Pharmacist support: Questions about side effects? Our pharmacists are always available
• Refill reminders: Never miss a dose due to running out of medication
• Home delivery: Convenient delivery right to your door

Need help affording Promacta? Call QuickRx at (917) 830-2525 or (800) 496-6111 for a free copay assistance consultation. You can also apply online.

Frequently Asked Questions: Promacta Side Effects

What are the most common side effects of Promacta?

The most common Promacta side effects vary by condition but generally include nausea, diarrhea, upper respiratory tract infection, fatigue, headache, and abnormal liver function tests. In children with ITP, upper respiratory infections and nasopharyngitis (throat inflammation) are most common. Most side effects improve as your body adjusts to the medication.

Does Promacta cause liver damage?

Promacta can cause liver problems (hepatotoxicity), which is why regular liver function monitoring is required during treatment. Signs of liver problems include yellowing of the skin or eyes, dark urine, unusual tiredness, and right upper stomach pain. Your healthcare provider will check your liver function with blood tests before starting treatment and regularly throughout therapy.

Can Promacta cause blood clots?

Yes, Promacta can increase the risk of blood clots because it stimulates platelet production. If platelet counts become too high, the risk of clotting increases. Blood clots can occur in the legs (DVT), lungs (pulmonary embolism), liver, or brain (stroke). Regular platelet monitoring helps prevent this complication by keeping counts in the safe range.

Does Promacta cause cataracts?

Promacta may cause new cataracts or worsen existing cataracts. Your healthcare provider may recommend baseline eye exams before starting treatment and regular monitoring during therapy. Report any vision changes to your doctor, including blurry vision, difficulty seeing at night, or seeing halos around lights.

What happens when you stop taking Promacta?

When you stop taking Promacta, your platelet counts may drop—sometimes lower than they were before treatment. This can increase your risk of bleeding. Your healthcare provider will monitor your blood counts weekly for at least 4 weeks after stopping Promacta and may adjust other treatments as needed.

Can I take Promacta with food?

Promacta should be taken on an empty stomach—1 hour before or 2 hours after a meal. Additionally, avoid dairy products and foods high in calcium, iron, or other minerals within 4 hours of your dose, as these can reduce how much medication your body absorbs.

How long do Promacta side effects last?

Many common Promacta side effects, like nausea and fatigue, improve within the first few weeks as your body adjusts to the medication. However, the risk of serious side effects like liver problems and blood clots continues throughout treatment, which is why ongoing monitoring is important. Talk to your healthcare provider if any side effect persists or worsens.

Who should not take Promacta?

Promacta should not be used by patients with myelodysplastic syndrome (MDS) or other blood cancers, as it could cause these conditions to worsen. People who are allergic to eltrombopag or any ingredients in Promacta should also not take it. Tell your healthcare provider about all your medical conditions before starting treatment.

Get Support from QuickRx

Managing Promacta side effects is easier when you have expert support. QuickRx Specialty Pharmacy is here to help you throughout your treatment journey.

Three Ways to Get Help

1. Call QuickRx for Pharmacist Support 📞
(917) 830-2525 | (800) 496-6111
Have questions about a side effect? Our pharmacists are available around the clock.

2. Get Help Affording Your Promacta
Visit our Promacta copay assistance page →
Many patients pay $0-$50 per month with copay assistance.

3. Learn More About Promacta
Read our complete Promacta guide →

Questions about Promacta side effects or need help affording your medication? Call QuickRx today at (917) 830-2525 or (800) 496-6111. We’re here to help.

Medical References & Sources

1. U.S. Food and Drug Administration. Promacta (eltrombopag) Information. Accessed January 2026.
2. Novartis Pharmaceuticals. Promacta Prescribing Information. Accessed January 2026.
3. MedlinePlus. Eltrombopag Drug Information. Accessed January 2026.
4. Mayo Clinic. Eltrombopag (Oral Route) Precautions. Accessed January 2026.
5. National Heart, Lung, and Blood Institute. Immune Thrombocytopenia. Accessed January 2026.

Disclaimer: This article provides general information about Promacta (eltrombopag) side effects and is intended for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider with questions about side effects or your medical condition. QuickRx Specialty Pharmacy does not provide medical advice or treatment recommendations.

Last Updated: January 2026
Author: Paola Larrabure, Pharma Content Manager
Reviewed By: Julia Kravtsova, PharmD, Head Patient Navigator, QuickRx Specialty Pharmacy