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Onpattro Side Effects

Generic name: patisiran

Medically reviewed by Last updated on Apr 30, 2023.

Note: This document contains side effect information about patisiran. Some dosage forms listed on this page may not apply to the brand name Onpattro.

Applies to patisiran: intravenous solution.

Serious side effects of Onpattro

Along with its needed effects, patisiran (the active ingredient contained in Onpattro) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking patisiran:

More common

  • Back pain
  • body aches or pain
  • chest tightness
  • chills
  • cough
  • difficulty in breathing
  • ear congestion
  • feeling of warmth
  • fever
  • headache
  • loss of voice
  • nasal congestion
  • nausea
  • redness of the face, neck, arms, and occasionally, upper chest
  • runny nose
  • sneezing
  • sore throat
  • unusual tiredness or weakness
  • vomiting

Less common

  • Blurred vision
  • chest pain
  • cough producing mucus
  • dizziness
  • dry eye
  • fainting
  • pounding, slow heartbeat
  • seeing floating dark spots or material before the eyes


  • Blistering, crusting, irritation, itching, or reddening of the skin burning, pain, redness, or swelling at the injection site
  • changes in skin color, pain, tenderness, or swelling of the foot or leg
  • cracked, dry, scaly skin

Other side effects of Onpattro

Some side effects of patisiran may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

  • Belching
  • feeling of constant movement of self or surroundings
  • heartburn
  • indigestion
  • muscle spasms
  • sensation of spinning
  • stomach discomfort, upset, or pain

For Healthcare Professionals

Applies to patisiran: intravenous solution.


The most common adverse reactions were upper respiratory tract infections, infusion-related reactions and peripheral edema.[Ref]


There were 3.7% of patients with atrioventricular heart block, of which three cases were complete AV block.[Ref]

Common (1% to 10%): Atrioventricular (AV) heart block[Ref]


Upper respiratory infections included nasopharyngitis, upper respiratory tract infection, respiratory tract infection, pharyngitis, rhinitis, sinusitis, viral upper respiratory tract infection, and upper respiratory tract congestion.[Ref]

Very common (10% or more): Upper respiratory infection (29%)

Common (1% to 10%): Dyspnea, bronchitis[Ref]


Common (1% to 10%): Dry eye, blurred vision, vitreous floaters[Ref]


Common (1% to 10%): Muscle spasms, arthralgia[Ref]


Common (1% to 10%): Vertigo[Ref]


Common (1% to 10%): Erythema[Ref]


Common (1% to 10%): Dyspepsia[Ref]


Among patients who experienced infusion-related reactions (IRR), up to 79% occurred within the first two infusions and the frequency decreased over time. IRR led to infusion interruption in 5% of patients and resulted in permanent discontinuation in less than 1%.

There was no evidence that anti-drug antibodies influenced the clinical efficacy, safety, pharmacokinetic or pharmacodynamic profiles of this drug; however, the data are limited.[Ref]

Very common (10% or more): Infusion-related reactions (up to 19%)

Common (1% to 10%): Antibody formation[Ref]


In all cases of peripheral edema, the severity was mild to moderate, and did not result in treatment discontinuation.[Ref]

Very common (10% or more): Peripheral edema (29.7%)

Uncommon (0.1% to 1%): Extravasation[Ref]

Frequently asked questions


1. Product Information. Onpattro (patisiran). Alnylam Australia Pty Ltd. 2022.

2. Product Information. Onpattro (patisiran). Alnylam Pharmaceuticals. 2023.

3. Product Information. Onpattro (patisiran). Alnylam UK Ltd. 2022.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.