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Thallous Chloride Tl 201 Injection


Thallium Chloride Tl 201 Injection is a diagnostic radiopharmaceutical indicated for

  • Myocardial perfusion imaging with planar scintigraphy or single-photon emission computed tomography (SPECT) for the diagnosis of coronary artery disease by localization of:
    • Non-reversible defects (myocardial infarction) which may have prognostic value regarding survival.
    • Reversible defects (myocardial ischemia) when used in conjunction with exercise or pharmacologic stress.
  • Localization of sites of parathyroid hyperactivity pre- and post- operatively in patients with elevated serum calcium and parathyroid hormone levels.


  • Anaphylactoid reactions (hypotension, pruritus, flushing, and diffuse rash) have been reported.
  • Stress Testing: Induction of cardiovascular stress may be associated with myocardial infarction, arrhythmia, hypotension, bronchoconstriction, cerebrovascular events and other serious adverse events.
  • Thallous Chloride Tl 201 contributes to the cumulative radiation exposure. When considering administration of Thallous Chloride injection to women of child-bearing potential, consider the radiation risks for a fetus. Use the lowest dose necessary for imaging and ensure safe handling to protect the patient and health care worker.
  • Risk of Extravasation: Inject Thallous Chloride Tl 201 strictly intravenously to avoid local tissue accumulation and irradiation.


  • Serious adverse reactions may include anaphylactoid reactions (characterized by cardiovascular, respiratory and cutaneous symptoms), hypotension, pruritus, flushing, and diffuse rash.  Serious adverse reactions in patients who have undergone stress testing include myocardial infarction, arrhythmia, hypotension, bronchoconstriction, and cerebrovascular events.
  • Common adverse reactions include itching, nausea, vomiting, mild diarrhea, tremor, shortness of breath, chills, fever, conjunctivitis, sweating, and blurred vision.


  • Assess the pregnancy status of women of childbearing potential prior to performing imaging procedures with Thallous Chloride Tl 201 Injection.
  • Breast feeding: Thallous Chloride Tl 201 is excreted in human milk.  Discontinue nursing or express and discard milk for a minimum of 2 weeks after administration of Thallous Chloride Tl 201.
  • Pediatrics: Safety and effectiveness have not been established in pediatric patients.

How Supplied

Distribution Direct
Calibration Day Tuesday through Saturday of each week
Expiration 9 days post manufacture or 6 days after calibration, whichever occurs first
Storage Conditions Controlled room temperature: 20° to 25°C (68° to 77°F)

Order Information

Description Qty Unit Size Order # 11 Digit NDC
Vial, 2.8 mCi activity 1 each 2.8 mL N12028 00019912028
Vial, 5.6 mCi activity 1 each 5.6 mL N12056 00019912056
Vial, 6.3 mCi activity 1 each 6.3 mL N12063 00019912063
Vial, 9.9 mCi activity (5-day) 1 each 9.9 mL N12099 00019912099


How long after injection should imaging begin for a Tl 201 exercise stress test?Per the package insert, when utilized in conjunction with exercise stress testing, imaging should begin 10 minutes after administration of Tl 201.
How long after injection should imaging begin for a Tl 201 rest study? Per the package insert, for resting Tl 201 studies, imaging should begin 10-20 minutes after injection.
What is the expiration date for Tl 201? This drug should not be used after 6 days from the calibration date, or 9 days from the date of manufacture, whichever comes first.
Who do I contact for additional safety or usage questions?Call Mallinckrodt Product Monitoring at 800.778.7898.