What the label lists and what reports show
Eltrombopag side effects
Eltrombopag's FDA label: “Across all indications, the most common adverse reactions (≥ 20% in any indication) were: anemia, nausea, pyrexia, alanine aminotransferase increased, cough, fatigue, headache, and diarrhea.” FAERS holds 22,949 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is platelet count decreased (4,029 reports).
- Generic listed
- Boxed warning
Check it at the source: the eltrombopag FDA label on DailyMed (effective December 18, 2025, Novartis Pharmaceuticals Corporation); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of PROMACTA?PROMACTA may cause serious side effects, including: See “What is the most important information I should know about PROMACTA?” Increased risk of worsening of a precancerous blood condition called myelodysplastic syndrome (MDS) to acute myelogenous leukemia (AML). PROMACTA is not for use in people with a precancerous condition called myelodysplastic syndromes (MDS). See “What is PROMACTA?” If you have MDS and receive PROMACTA, you have an increased risk that your MDS condition may worsen and become a blood cancer called AML. If your MDS worsens to become AML, you may have an increased risk of death from AML. High platelet counts and higher risk for blood clots. Your risk of getting a blood clot is increased if your platelet count is too high during treatment with PROMACTA. […]
Source: FDA drug label, Novartis Pharmaceuticals Corporation, effective December 18, 2025 (SPL set 7714a0ed-34bb-46e6-a0a5-b363908b22c2), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsAcross all indications, the most common adverse reactions (≥ 20% in any indication) were: anemia, nausea, pyrexia, alanine aminotransferase increased, cough, fatigue, headache, and diarrhea.
Table 11. Adverse Reactions (≥ 10% and Greater Than Placebo) From Two Placebo-controlled Trials in Adults With Chronic Hepatitis C
| Adverse reaction | PROMACTA + Peginterferon/Ribavirin n = 955 (%) | Placebo + Peginterferon/Ribavirin n = 484 (%) |
|---|---|---|
| Anemia | 40 | 35 |
| Pyrexia | 30 | 24 |
| Fatigue | 28 | 23 |
| Headache | 21 | 20 |
| Nausea | 19 | 14 |
| Diarrhea | 19 | 11 |
| Decreased appetite | 18 | 14 |
| Influenza-like illness | 18 | 16 |
| Insomnia a | 16 | 15 |
| Asthenia | 16 | 13 |
| Cough | 15 | 12 |
| Pruritus | 15 | 13 |
| Chills | 14 | 9 |
| Myalgia | 12 | 10 |
| Alopecia | 10 | 6 |
| Peripheral edema | 10 | 5 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions associated with PROMACTA are described in other sections. Hepatic Decompensation in Patients with Chronic Hepatitis C [see Warnings and Precautions (5.1)] Hepatotoxicity [see Warnings and Precautions (5.2)] Increased Risk of Death and Progression of Myelodysplastic Syndromes to Acute Myeloid Leukemia [see Warnings and Precautions (5.3)] Thrombotic/Thromboembolic Complications [see Warnings and Precautions (5.4)] Cataracts [see Warnings and Precautions (5.5)] Across all indications, the most common adverse reactions (≥ 20% in any indication) were: anemia, nausea, pyrexia, alanine aminotransferase increased, cough, fatigue, headache, and diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Novartis Pharmaceuticals Corporation at 1-888-669-6682 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. Persistent or Chronic Immune Thrombocytopenia Adults: In clinical trials, hemorrhage was the most common serious adverse reaction and most hemorrhagic reactions followed discontinuation of PROMACTA. …
Source: FDA drug label, Novartis Pharmaceuticals Corporation, effective December 18, 2025 (SPL set 7714a0ed-34bb-46e6-a0a5-b363908b22c2), via openFDA; the full label on DailyMed
What do FAERS reports show?
22,949 reports list eltrombopag among the medicines taken, each a report of something that happened, not proof the medicine caused it; 4,880 are coded as a death and 5,578 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 19 reactions below, 10 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Eltrombopag: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions