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Drug Safety-related Labeling Changes (SrLC)

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ZARONTIN (NDA-012380)

(ETHOSUXIMIDE)

Safety-related Labeling Changes Approved by FDA Center for Drug Evaluation and Research (CDER)

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10/28/2021 (SUPPL-37)

Approved Drug Label (PDF)

5 Warnings and Precautions

WARNINGS

(Additions and/or revisions underlined)

Blood Dyscrasias:

Blood dyscrasias, including some with fatal outcome, have been reported to be associated with the use of ethosuximide; therefore, periodic blood counts should be performed. Should signs and/or symptoms of infection (e.g., sore throat, fever) develop, blood counts should be considered at that point.

Drug-Induced Immune Thrombocytopenia:

Drug-induced immune thrombocytopenia (DITP) has been reported with ethosuximide. In the reported cases, the onset of symptoms occurred 1 to 3 weeks after initiation of ethosuximide; one patient had recurrence of symptoms within 1 day of a subsequent re-challenge with the drug. In those cases in which the platelet count was specified, the nadir was 2,000 and 3,000/mm3. When DITP is suspected, discontinue Zarontin, monitor serial platelet counts, and treat as appropriate. If possible, assess the presence of drug- dependent antiplatelet antibodies. Avoid future use of Zarontin in patients with history of ethosuximide- induced DITP.

Effects on Liver and Kidneys:

Ethosuximide is capable of producing morphological and functional changes in the animal liver. In humans, abnormal liver and renal function studies have been reported. Ethosuximide should be administered with extreme caution to patients with known liver or renal disease. Periodic urinalysis and liver function studies are advised for all patients receiving the drug.

Systemic Lupus Erythematosus:

Cases of systemic lupus erythematosus have been reported with the use of ethosuximide. The physician should be alert to this possibility.

6 Adverse Reactions

(Additions and/or revisions underlined)

Body As A Whole: Allergic reaction, Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS).

Gastrointestinal System: Gastrointestinal symptoms occur frequently and include anorexia, vague gastric upset, nausea and vomiting, cramps, epigastric and abdominal pain, weight loss, and diarrhea. There have been reports of gum hypertrophy and swelling of the tongue.

Hemopoietic System: Hemopoietic complications associated with the administration of ethosuximide have included leukopenia, agranulocytosis, pancytopenia, with or without bone marrow suppression, eosinophilia, and thrombocytopenia (see WARNINGS).

Nervous System: Neurologic and sensory reactions reported during therapy with ethosuximide have included drowsiness, headache, dizziness, euphoria, hiccups, irritability, hyperactivity, lethargy, fatigue, and ataxia. Psychiatric or psychological aberrations associated with ethosuximide administration have included disturbances of sleep, night terrors, inability to concentrate, and aggressiveness. These effects may be noted particularly in patients who have previously exhibited psychological abnormalities. There have been rare reports of paranoid psychosis, increased libido, and increased state of depression with overt suicidal intentions.

Integumentary System: Dermatologic manifestations which have occurred with the administration of ethosuximide have included urticaria, pruritic erythematous rashes, Stevens-Johnson syndrome, and hirsutism.

Special Senses: Myopia.

Genitourinary System: Vaginal bleeding, microscopic hematuria.

05/17/2016 (SUPPL-36)

Approved Drug Label (PDF)

5 Warnings and Precautions

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)

  • Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), also known as multi organ hypersensitivity, has occurred with ZARONTIN. Some of these events have been fatal or life-threatening. DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy and/or facial swelling, in association with other organ system involvement, such as hepatitis, nephritis, hematologic abnormalities, myocarditis, or myositis, sometimes resembling an acute viral infection. Eosinophilia is often present. This disorder is variable in its expression, and other organ systems not noted here may be involved. It is important to note that early manifestations of hypersensitivity (e.g. fever, lymphadenopathy) may be present even though rash is not evident. If such signs or symptoms are present, the patient should be evaluated immediately. ZARONTIN should be discontinued if an alternative etiology for the signs or symptoms cannot be established.
Serious Dermatologic Reactions

  • Serious dermatologic reactions, including Stevens-Johnson syndrome (SJS), have been reported with ethosuximide treatment. SJS can be fatal. The onset of symptoms is usually within 28 days, but can occur later. Zarontin should be discontinued at the first sign of a rash, unless the rash is clearly not drug-related. If signs or symptoms suggest SJS, use of this drug should not be resumed and alternative therapy should be considered.

6 Adverse Reactions

  • Body As A Whole: Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS).

17 PCI/PI/MG (Patient Counseling Information/Patient Information/Medication Guide)

MG - ZARONTIN can cause serious side effects, including:

Drug reactions that may affect different parts of the body such as your liver, kidneys, heart, or blood cells. You may or may not have a rash with these types of reactions. These reactions can be very serious and can cause death. Call your healthcare provider right away if you have any of these symptoms:

  • joint pain and swelling
  • muscle pain
  • fatigue, weakness
  • low-grade fever
  • pain in the chest that is worse with breathing
  • skin rash
  • swollen lymph glands
  • swelling of your face
  • yellowing of your skin or the white part of your eyes