Sylvant Side Effects

Generic name: siltuximab

Medically reviewed by Drugs.com. Last updated on Apr 29, 2025.

Note: This document provides detailed information about Sylvant.

Applies to siltuximab: intravenous powder for solution 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.

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Tell your doctor if you are pregnant or planning to become pregnant. You must use an effective form of birth control to keep from getting pregnant during treatment with this medicine and for 3 months after the last dose.

Your body's ability to fight infections may be reduced while you are receiving siltuximab (the active ingredient contained in Sylvant) It is very important that you call your doctor at the first sign of any infection. Check with your doctor right away if you have any of the following symptoms while receiving this medicine: a fever, chills, cough, flu-like symptoms, or unusual tiredness or weakness.

While you are being treated with siltuximab, do not have any immunizations (vaccines) without your doctor's approval. Live virus vaccines should not be given with this medicine or soon after you receive it.

This medicine may cause a serious allergic reaction called anaphylaxis, which can be life-threatening and requires immediate medical attention. Tell your doctor right away if you have a rash, itching, trouble breathing or swallowing, or any swelling of your hands, face, or mouth while you are receiving this medicine.

Siltuximab may cause an infusion reaction while you are receiving it or right after the infusion ends. Check with your doctor or nurse right away if you have back pain, chest pain or discomfort, fast or uneven heartbeat, nausea or vomiting, trouble breathing, or redness of the face, neck, arms, and upper chest.

This medicine may increase your risk for stomach or bowel perforation. Tell your doctor right away if you have any of the following symptoms: severe abdominal or stomach pain or cramps, bloody, black, or tarry stools, or vomiting of material that looks like coffee grounds.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of Sylvant

Along with its needed effects, siltuximab 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:

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:

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]

See also:

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