Sylvant Side Effects

Generic name: siltuximab

Medically reviewed by Drugs.com. Last updated on Feb 28, 2025.

Note: This document provides detailed information about Sylvant Side Effects associated with siltuximab. Some dosage forms listed on this page may not apply specifically 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 side effects

• black, tarry stools
• bleeding gums
• bloating or swelling of the face, arms, hands, lower legs, or feet
• bloody urine
• blurred vision
• body aches or pain
• chills
• confusion
• cough
• decreased frequency or amount of urine
• difficulty with breathing
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• ear congestion
• fever
• full or bloated feeling
• headache
• increased thirst
• loss of appetite
• loss of voice
• lower back or side pain
• nasal congestion
• nausea
• pinpoint red spots on the skin
• pressure in the stomach
• rapid weight gain
• runny nose
• sneezing
• sore throat
• stomach pain
• sweating
• swelling of the abdominal or stomach area
• tingling of the hands or feet
• unusual bleeding or bruising
• unusual tiredness or weakness
• unusual weight gain or loss
• vomiting

Less common side effects

• back pain
• chest pain or discomfort
• dizziness
• dry mouth
• fainting
• fast, irregular, pounding, or racing heartbeat or pulse
• feeling of warmth
• flushing or redness of the skin
• lightheadedness
• rapid breathing
• redness of the face, neck, arms, and occasionally, upper chest
• sunken eyes
• unusually warm skin
• wrinkled skin

Rare side effects

• difficulty with swallowing
• hives, itching, or skin rash
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• tightness in the chest

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 side effects

• difficulty having a bowel movement
• difficulty with moving
• joint pain, stiffness, or swelling
• muscle pain or stiffness
• rash with flat lesions or small raised lesions on the skin

Less common side effects

• darkening of the skin
• decreased appetite
• dry skin
• skin rash, encrusted, scaly, and oozing

For healthcare professionals

Applies to siltuximab: intravenous powder for injection.

General adverse events

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

Respiratory

• Very common (10% or more): Upper respiratory tract infection (63%), nasopharyngitis (13%)
• Common (1% to 10%): Lower respiratory tract infection, oropharyngeal pain^[Ref]

Dermatologic

• Very common (10% or more): Rash (28%), pruritus (28%), eczema
• Common (1% to 10%): Skin hyperpigmentation, psoriasis, dry skin^[Ref]

Gastrointestinal

• 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]

Metabolic

• Very common (10% or more): Weight gain (19%), hyperuricemia (11%), localized edema
• Common (1% to 10%): Hypertriglyceridemia, hypercholesterolemia, decreased appetite, dehydration^[Ref]

Cardiovascular

• Very common (10% or more): Edema (26%), hypertension
• Common (1% to 10%): Hypotension^[Ref]

Hypersensitivity

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

Other

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

Musculoskeletal

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

Renal

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

Hematologic

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

Nervous system

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

Immunologic

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

Local

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

Genitourinary

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

Further information

Sylvant side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer