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Sylvant Side Effects

Generic name: siltuximab

Medically reviewed by Last updated on Aug 3, 2023.

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

Applies to siltuximab: intravenous powder for solution.

Serious side effects of Sylvant

Along with its needed effects, siltuximab (the active ingredient contained in Sylvant) 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 siltuximab:

More common

Less common


Other side effects of Sylvant

Some side effects of siltuximab 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:

More common

Less common

For Healthcare Professionals

Applies to siltuximab: intravenous powder for injection.


The most common adverse reactions were pruritus, weight gain, rash, hyperuricemia, and upper respiratory tract infection.[Ref]


Very common (10% or more): Upper respiratory tract infection (63%), nasopharyngitis (13%)

Common (1% to 10%): Lower respiratory tract infection, oropharyngeal pain[Ref]


Very common (10% or more): Rash (28%), pruritus (28%), eczema

Common (1% to 10%): Skin hyperpigmentation, psoriasis, dry skin[Ref]


Very common (10% or more): Diarrhea (32%), abdominal pain/abdominal distention (12%), oropharyngeal pain, nausea, vomiting, constipation, gastroesophageal reflux disease, mouth ulceration

Frequency not reported: Gastrointestinal perforation[Ref]


Very common (10% or more): Weight gain (19%), hyperuricemia (11%), localized edema

Common (1% to 10%): Hypertriglyceridemia, hypercholesterolemia, decreased appetite, dehydration[Ref]


Very common (10% or more): Edema (26%), hypertension

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


Common (1% to 10%): Anaphylactic reaction[Ref]


Very common (10% or more): Fatigue (21%)[Ref]


Very common (10% or more): Pain in extremities (21%), arthralgia (21%)[Ref]


Common (1% to 10%): Renal impairment[Ref]


Very common (10% or more): Thrombocytopenia, neutropenia[Ref]

Nervous system

Very common (10% or more): Headache, dizziness[Ref]


Uncommon (0.1% to 1%): Positive test for anti-siltuximab (the active ingredient contained in Sylvant) antibodies[Ref]


Common (1% to 10%): Infusion related reactions (e.g., back pain, chest pain/discomfort, nausea, vomiting, flushing, erythema, palpitations)[Ref]


Very common (10% or more): Urinary tract infection[Ref]


1. Product Information. Sylvant (siltuximab). Janssen Biotech, Inc. 2014.

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.