Drug Safety-related Labeling Changes (SrLC)

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Drug Safety-related Labeling Changes (SrLC) Database

ANDA	Abbreviated New Drug Application
BLA	Biologics License Application
CDER	Center for Drug Evaluation and Research
MG	Medication Guide
NDA	New Drug Application
PCI	Patient Counseling Information
PI	Patient Information
PLR	Physician Labeling Rule
PLLR	Pregnancy and Lactation Labeling Rule
Italics	For the most part, italics indicate an FDA comment such as: Additions and/or revisions underlined These italics usually appear at the beginning of the section. In some cases, italics may be an inherent part of the label, and will most often appear in the body of the section.
Underlines	Any text that is underlined indicates text that has been added or revised. There are exceptions where underlining occurs in a section subtitle or heading. This is the case when there is just one word underlined in the body of the text.

Sections

BW	Box Warning
WP	Warnings and Precautions all in one section (PLR-format) Warnings as one section (pre-PLR format) Precautions as one section (pre-PLR format)
AR	Adverse Reactions (in pre-PLR format, this may be a subheading under precautions).
DI	Drug Interactions (in pre-PLR format, this may be a subheading under precautions).
USP	Use in Specific Populations (Inclusive on one or more of the following: Pregnancy; Lactation (PLLR- format); Nursing Mothers (pre-PLLR format); Females and Males of Reproductive Potential (PLLR format only); Pediatric Use, Geriatric Use, Renal Impairment, Hepatic Impairment, Sex, Race (these last six may be a subheading of precautions if label in pre-PLLR format.
PCI/PI/MG	Patient Counseling Information (PLR format only) - summarizes the information that a health care provider should convey to a patient (or caregiver when applicable) when a counseling discussion is taking place (e.g., a physician prescribing a drug during an office visit, a nurse providing discharge instructions at a hospital, or a pharmacist conveying information at a pharmacy). Patient Information - FDA approved patient labeling. Medication Guide - paper handouts that come with many prescription medicines. The guides address issues that are specific to particular drugs and drug classes, and they contain FDA-approved information that can help patients avoid serious adverse events.

Only NDAs and CDER regulated BLAs are included in this database. ANDAs are not included.

Applications that remain active, even if the product has been discontinued, undergo safety-related labeling changes.

THALLOUS CHLORIDE TL 201 (NDA-018150)

(THALLOUS CHLORIDE TL-201)

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

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12/10/2025 (SUPPL-29)

Approved Drug Label (PDF)

5 Warnings and Precautions

5.1 Hypersensitivity Reactions

Subsection title revised

Additions and/or revisions underlined:

Thallous Chloride Tl 201 Injection may cause anaphylactic reactions characterized by cardiovascular, respiratory, and cutaneous symptoms [see Adverse Reactions (6)]. Have resuscitation equipment and trained staff readily available.

5.2 Risks Associated with Stress Testing

Additions and/or revisions underlined:

Induction of cardiovascular stress might be associated with serious adverse reactions such as myocardial infarction, arrhythmia, hypotension or hypertension, ECG abnormalities, chest pain, bronchoconstriction, and cerebrovascular events [see Adverse Reactions (6)]. Perform stress testing in the setting where cardiac resuscitation equipment and trained staff are readily available. Perform pharmacologic stress in accordance with the pharmacologic stress agent’s prescribing information.

5.3 Radiation Risk

Subsection title revised

Additions and/or revisions underlined:

Thallous Chloride Tl 201 Injection contributes to a patient's overall long-term cumulative radiation exposure. Long-term cumulative radiation exposure is associated with an increased risk of cancer. Ensure safe handling to minimize radiation exposure to patients and health care providers. Advise patients to hydrate before and after administration and to void frequently after administration [see Dosage and Administration (2.1, 2.3)].

5.4 Injection Site Reactions and Tissue Damage

Subsection title revised

Additions and/or revisions underlined:

Injection site reactions and extravasation have been reported after administration of Thallous Chloride Tl 201 Injection [see Adverse Reactions (6)]. Administer Thallous Chloride Tl 201 Injection strictly into the vein to avoid local tissue accumulation and irradiation. Confirm intravenous patency before injection.

6 Adverse Reactions

Additions and/or revisions underlined:

The following clinically significant adverse reactions are described elsewhere in the labeling:

Hypersensitivity Reactions [see Warnings and Precautions (5.1)]
Risk Associated with Stress Testing [see Warnings and Precautions (5.2)]
Injection Site Reactions and Tissue Damage [see Warnings and Precautions (5.4)]

The following adverse reactions associated with the use of Thallous Chloride Tl 201 Injection were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure:

Cardiovascular, respiratory, and cerebrovascular disorders: myocardial infarction, arrhythmia, hypotension, bronchoconstriction, and cerebrovascular events in patients who have undergone stress testing

Gastrointestinal disorders: nausea, vomiting, and diarrhea

General disorders and administration site conditions: injection site reactions (burning, pain, redness, swelling, warmth, and tissue damage with chronic ulcer formation), chills, fever, and sweating

Immune system disorders: hypersensitivity (anaphylaxis, hypotension, shortness of breath, pruritus, flushing, and diffuse rash)

8 Use in Specific Populations

8.1 Pregnancy

Additions and/or revisions underlined:

Risk Summary

There are no data on Thallous Chloride Tl 201 Injection use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Studies using human placentas demonstrate that thallous chloride Tl 201 crosses the placenta. No animal reproductive studies have been conducted.

All radiopharmaceuticals, including Thallous Chloride Tl 201 Injection have the potential to cause fetal harm depending on the fetal stage of development and the magnitude of the radiation dose. If considering administration of Thallous Chloride Tl 201 Injection to a pregnant woman, inform the patient about the potential for adverse pregnancy outcomes based on the radiation dose from Thallous Chloride Tl 201 Injection and gestational timing of exposure.

The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defects, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 3% and 10% to 20%, respectively.

8.2 Lactation

Additions and/or revisions underlined:

Risk Summary

Thallous chloride Tl 201 has been detected in the milk of lactating women. There are no data on the effects of thallous chloride Tl 201 on milk production or the effects of thallous chloride Tl 201 on the breastfed infant.

Exposure of the breastfed infant to thallous chloride Tl 201 can be minimized by advising a lactating woman to temporarily discontinue breastfeeding and pump and discard milk for a minimum of 96 hours after administration of Thallous Chloride Tl 201 Injection. Minimize close contact with infants if the administered dose would result in an effective dose greater than 1 mSv to the infant. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Thallous Chloride Tl 201 Injection and any potential adverse effects on the breastfed infant from Thallous Chloride Tl 201 Injection or from the underlying maternal condition.

8.5 Geriatric Use

Newly added subsection:

Clinical studies of Thallous Chloride Tl 201 Injection for myocardial perfusion imaging did not include sufficient numbers of subjects aged younger than 65 years to determine whether they respond differently from younger subjects. Other reported experience has not revealed clinically relevant differences in the response of elderly in comparison to younger patients.

This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

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

PATIENT COUNSELING INFORMATION

Additions and/or revisions underlined:

Radiation Risk

Advise patients of the radiation risk of Thallous Chloride Tl 201 Injection. Instruct patients to drink water to ensure adequate hydration prior to administration of Thallous Chloride Tl 201 Injection and to continue drinking and voiding frequently following administration to reduce radiation exposure [see Warnings and Precautions (5.3)].

Pregnancy

Inform pregnant women of the risk of fetal exposure to radiation dose if they undergo an imaging procedure with Thallous Chloride Tl 201 Injection [see Use in Specific Populations (8.1)].

Lactation

Advise a lactating woman to temporarily discontinue breastfeeding and to pump and discard breastmilk for at least 96 hours after administration of Thallous Chloride Tl 201 Injection to minimize radiation exposure to a breastfed infant [see Use in Specific Populations (8.2)].

07/13/2016 (SUPPL-27)

Approved Drug Label (PDF)

5 Warnings and Precautions

Risk of Extravasation and Tissue Damage (and Tissue Damage added)

Addition of:

Confirm intravenous patency before injection.

6 Adverse Reactions

Postmarketing Experience (addition)

The following adverse reactions have been identified during post-approval use of Thallous Chloride Tl 201. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: Injection site reactions and extravasation of Tl-201 have been reported: burning, pain, redness, swelling, warmth, and, in one case, tissue damage with chronic ulcer formation.