What the label lists and what reports show
Avacopan side effects
Avacopan's FDA label: “The most common adverse reactions (≥ 5%) are: nausea, headache, hypertension, diarrhea, vomiting, rash, fatigue, upper abdominal pain, dizziness, blood creatinine increased, and paresthesia.” FAERS holds 6,343 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 diarrhoea (259 reports).
- No generic listed
Check it at the source: the avacopan FDA label on DailyMed (effective June 2, 2026, ChemoCentryx, Inc.); 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 TAVNEOS?TAVNEOS may cause serious side effects, including: See " What is the most important information I should know about TAVNEOS? " Serious allergic reactions. TAVNEOS may cause serious allergic reactions. Stop taking TAVNEOS and get emergency medical help right away if you have any of the following signs of a serious allergic reaction: shortness of breath or trouble breathing swollen lips, tongue, throat, or face trouble swallowing chest pain feeling dizzy or faint moderate or severe abdominal pain or vomiting Hepatitis B virus (HBV) reactivation. Before you take TAVNEOS, your healthcare provider will do blood tests to check for hepatitis B (HBV) infection. If you have had hepatitis B or are a carrier of hepatitis B virus, taking TAVNEOS could cause the virus to become an active infection again. […]
Source: FDA drug label, ChemoCentryx, Inc., effective June 2, 2026 (SPL set c93cbc0b-29a3-46a5-9c85-41815ea5cf4a), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (≥ 5%) are: nausea, headache, hypertension, diarrhea, vomiting, rash, fatigue, upper abdominal pain, dizziness, blood creatinine increased, and paresthesia.
Table 1. Adverse Reactions Reported in ≥ 5% of Patients and Higher in TAVNEOS Group vs. Prednisone Group in Phase 3 Trial
| Adverse Reaction | Prednisone (N = 164) n (%) | TAVNEOS (N = 166) n (%) |
|---|---|---|
| Nausea | 34 (20.7) | 39 (23.5) |
| Headache | 23 (14.0) | 34 (20.5) |
| Hypertension | 29 (17.7) | 30 (18.1) |
| Diarrhea | 24 (14.6) | 25 (15.1) |
| Vomiting | 21 (12.8) | 25 (15.1) |
| Rash | 13 (7.9) | 19 (11.4) |
| Fatigue | 15 (9.1) | 17 (10.2) |
| Upper abdominal pain | 10 (6.1) | 11 (6.6) |
| Dizziness | 10 (6.1) | 11 (6.6) |
| Blood creatinine increased | 8 (4.9) | 10 (6.0) |
| Paresthesia | 7 (4.3) | 9 (5.4) |
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 adverse reactions are discussed in greater detail in other sections of the labeling: Hepatotoxicity [see Warnings and Precautions (5.1) ] Hypersensitivity Reactions [see Warnings and Precautions (5.2) ] Hepatitis B Virus (HBV) Reactivation [see Warnings and Precautions (5.3) ] Serious Infections [see Warnings and Precautions (5.4) ] The most common adverse reactions (≥ 5%) are: nausea, headache, hypertension, diarrhea, vomiting, rash, fatigue, upper abdominal pain, dizziness, blood creatinine increased, and paresthesia. To report SUSPECTED ADVERSE REACTIONS, contact Amgen Inc. at 1-800-77-AMGEN (1-800-772-6436) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because the 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. The identification of potential adverse drug reactions was based on safety data from the phase 3 clinical trial in which 330 patients with ANCA-associated vasculitis were randomized 1:1 to either TAVNEOS or prednisone [see Clinical Studies (14) ]. The mean age of patients was 60.9 years (range of 13 to 88 years), with a predominance of men (56.4%) and Caucasians (84.2%). …
Source: FDA drug label, ChemoCentryx, Inc., effective June 2, 2026 (SPL set c93cbc0b-29a3-46a5-9c85-41815ea5cf4a), via openFDA; the full label on DailyMed
What do FAERS reports show?
6,343 reports list avacopan among the medicines taken, each a report of something that happened, not proof the medicine caused it; 639 are coded as a death and 2,880 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. Reports rose sharply in 2025 (1,726, against a median of 0 a year): FAERS counts follow reporting, which news, litigation and label changes can drive, not how often a reaction happens. 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?
- Avacopan: 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