What the label lists and what reports show
Patisiran side effects
Patisiran's FDA label: “The most frequently reported adverse reactions (that occurred in at least 10% of ONPATTRO-treated patients and at least 3% more frequently than on placebo) were upper respiratory tract infections and infusion-related reactions ( 6.1 ) To report SUSPECTED …” FAERS holds 2,810 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 fatigue (173 reports).
- No generic listed
Check it at the source: the patisiran FDA label on DailyMed (effective September 8, 2025, Alnylam Pharmaceuticals, Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsThe most frequently reported adverse reactions (that occurred in at least 10% of ONPATTRO-treated patients and at least 3% more frequently than on placebo) were upper respiratory tract infections and infusion-related reactions ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Alnylam Pharmaceuticals at 1-877-256-9526 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Table 1: Adverse Reactions from the Placebo-Controlled Trial that Occurred in at Least 5% of ONPATTRO-treated Patients and at Least 3% More Frequently than in Placebo-treated Patients
| Adverse Reaction | ONPATTRO N=148 % | Placebo N=77 % |
|---|---|---|
| Upper respiratory tract infections Includes nasopharyngitis, upper respiratory tract… | 29 | 21 |
| Infusion-related reaction Infusion-related reaction symptoms include, but are not limited… | 19 | 9 |
| Dyspepsia | 8 | 4 |
| Dyspnea Not part of an infusion-related reaction. , Includes dyspnea and exertional… | 8 | 0 |
| Muscle spasms | 8 | 1 |
| Arthralgia | 7 | 0 |
| Erythema | 7 | 3 |
| Bronchitis Includes bronchitis, bronchiolitis, bronchitis viral, lower respiratory tract… | 7 | 3 |
| Vertigo | 5 | 1 |
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 are described elsewhere in the labeling: Infusion-Related Reactions [see Warnings and Precautions (5.1) ] The most frequently reported adverse reactions (that occurred in at least 10% of ONPATTRO-treated patients and at least 3% more frequently than on placebo) were upper respiratory tract infections and infusion-related reactions ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Alnylam Pharmaceuticals at 1-877-256-9526 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of ONPATTRO cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. A total of 224 patients with polyneuropathy caused by hereditary transthyretin-mediated amyloidosis (hATTR amyloidosis) received ONPATTRO in the placebo-controlled and open-label clinical studies, including 186 patients exposed for at least 1 year, 137 patients exposed for at least 2 years, and 52 patients exposed for at least 3 years. In the placebo-controlled study, 148 patients received ONPATTRO for up to 18 months (mean exposure 17.7 months). Baseline demographic and disease characteristics were generally similar between treatment groups. …
Source: FDA drug label, Alnylam Pharmaceuticals, Inc., effective September 8, 2025 (SPL set e87ec36f-b4b4-49d4-aea4-d4ffb09b0970), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,810 reports list patisiran among the medicines taken, each a report of something that happened, not proof the medicine caused it; 418 are coded as a death and 1,074 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 18 reactions below, 7 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?
- Patisiran: 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