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Tegsedi Side Effects

Generic name: inotersen

Medically reviewed by Last updated on Jan 10, 2024.

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

Applies to inotersen: subcutaneous solution.


Subcutaneous route (Solution)

ThrombocytopeniaInotersen causes reductions in platelet count that may result in sudden and unpredictable thrombocytopenia, which can be life-threatening.Testing prior to treatment and monitoring during treatment is required.GlomerulonephritisInotersen can cause glomerulonephritis that may require immunosuppressive treatment and may result in dialysis-dependent renal failure.Testing Prior to treatment and monitoring during treatment is required.TEGSEDI is only available through a restricted distribution program call the TEGSEDI REMS Program.

Serious side effects of Tegsedi

Along with its needed effects, inotersen (the active ingredient contained in Tegsedi) 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 immediately if any of the following side effects occur while taking inotersen:

More common

Less common

Other side effects of Tegsedi

Some side effects of inotersen 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:

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Less common

For Healthcare Professionals

Applies to inotersen: subcutaneous solution.


The more commonly reported adverse reactions have included injection site reactions, nausea, headache, fatigue, thrombocytopenia, and fever.[Ref]


Sudden and unpredictable platelet count reductions have been reported. Three clinical trial patients had sudden and severe thrombocytopenia with platelet counts below 25 x 10(9)/L. One patient died of a fatal intracranial hemorrhage. All 3 of these patients had treatment-emergent antiplatelet IgG antibodies detected shortly before or at the time of the severe thrombocytopenia. For 2 of these patients, platelet clumping cause by a reaction between antiplatelet antibodies and ethylenediaminetetraacetic acid (EDTA) caused a delay in interpretable platelet measurements which delayed diagnosis and treatment.

Very common (10% or more): Thrombocytopenia (24%), anemia (17%)

Common (1% to 10%): Eosinophilia


Very common (10% or more): Decreased renal function (14%), increased urine protein to creatinine ratio (UPCR; 15%); increased serum creatinine (11%)

Common (1% to 10%): Glomerulonephritis

Frequency not reported: Nephrotic syndrome, tubular proteinuria

Glomerulonephritis was reported in 3 treated patients during clinical trials; glomerulonephritis did not resolve with discontinuation and immunosuppressive therapy was necessary. One patient did not receive immunosuppressive treatment and remained dialysis-dependent.

Nephrotic syndrome was reported as accompanying cases of glomerulonephritis. Tubular proteinuria was reported and attributed to the accumulation of antisense oligonucleotides in the proximal tubule cells of the kidney. UPCR elevations to greater than 5 times the upper limit of normal (5xULN) occurred in 15% of drug treated patients compared to 8% in placebo patients.


Common (1% to 10%): Hypersensitivity reactions

Hypersensitivity reactions have been reported and generally occurred within 2 hours of receiving the drug. Reactions have included headache, chest pain, hypertension, chills, flushing, dysphagia, palmar erythema, eosinophilia, involuntary choreaform movements, arthralgia, myalgia, and flu-like symptoms. Drug antibodies were present when the reactions occurred.


ALT elevations to at least 3 times the upper limit of normal (3 x ULN) occurred in 8% of drug-treated patients compare to 3% of placebo patients; 3% of drug-treated patients had an ALT of 8 x ULN compared to 0% of placebo patients. Some patients had resolution of these ALT elevations with continued therapy.

One case of immune-mediated biliary disease was reported and a single case of autoimmune hepatitis with primary biliary cirrhosis in a patient with a family history of primary biliary cirrhosis.

Common (1% to 10%): ALT elevations

Uncommon (0.1% to 1%): Autoimmune hepatitis with primary biliary cirrhosis; biliary obstruction of unclear etiology

Frequency not reported: Immune-mediated biliary disease

Nervous system

Very common (10% or more): Headache (26%)

Common (1% to 10%): Paresthesia

Uncommon (0.1% to 1%): Carotid artery dissection and stroke; serious neurologic adverse reaction

Neurologic serious reactions consistent with inflammatory and immune effects have occurred. One patient developed a change in gait 2 months after the first dose, it progressed to paraparesis over 6 months. No radiologic evidence of spinal cord compression was found. Another patient developed progressive lumbar pain, weight loss, headache, vomiting, and impaired speech 7 months after starting therapy. Cerebrospinal fluid analysis showed elevated protein, and a lymphocyte-predominant pleocytosis that was negative for infection. This patient recovered after high-dose steroids and antibiotics and resumed therapy.


Very common (10% or more): Anti-drug antibodies

Common (1% to 10%): Influenza-like illness, bacterial infection

Frequency not reported: Immune thrombocytopenia, antineutrophil cytoplasmic autoantibody (ANCA) positive systemic vasculitis

Bacterial infection includes bacteremia, cellulitis staphylococcal, clostridium difficile infection, conjunctivitis bacterial, cystitis Escherichia, Helicobacter gastritis, Helicobacter infection, Staphylococcal infection.

Anti-drug antibodies were present in 30% of patients after 65 weeks of receiving this drug. As with other measures of anti-drug antibodies, the detection is highly dependent on the sensitivity and specificity of the assay. The assay used measured IgG isotypes only; other isotypes may be possible. Anti-drug antibodies were present in many case of adverse reactions, although the data was too limited to make definitive conclusions about the relationship.


Very common (10% or more): Injection site reactions (49%)

Injection site reactions included bruising, erythema, hematoma, hemorrhage, induration, inflammation, mass, edema, pain, pruritus, rash, swelling, and urticaria. Injection site reactions occurred in 49% of patients receiving this drug compared with 10% of placebo patients.


Very common (10% or more): Myalgia (15%), arthralgia (13%)


Common (1% to 10%): Decreased appetite


Common (1% to 10%): Dyspnea


Very common (10% or more): Fatigue (25%), fever (20%), chills (18%)


Arrhythmia included arrhythmia, atrial fibrillation, atrial flutter, bradyarrhythmia, bradycardia, extrasystoles, sinus arrhythmia, sinus bradycardia, supraventricular extrasystoles, tachycardia, and ventricular extrasystoles.

Very common (10% or more): Peripheral edema (19%), arrhythmia (13%), pre-syncope or syncope (13%)

Common (1% to 10%): Orthostasis


Common (1% to 10%): Contusion


Very common (10% or more): Nausea (31%), vomiting (15%)

Common (1% to 10%): Dry mouth

Frequently asked questions


1. Product Information. Tegsedi (inotersen). Akcea Therapeutics. 2018.

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.