Boxed warning added to labels for treatment of conditions in postmenopausal women with fezonatant

After the U.S. Food and Drug Administration (FDA) reviewed a postmarketing report of serious liver injury, the prescribing information for Fezolinetant has been updated to include a new boxed warning about the risk of hepatotoxicity. Fezonatant is an oral neurokinin 3 receptor antagonist specifically indicated for the treatment of moderate to severe vasomotor symptoms associated with menopause. This update primarily emphasizes the assessment of a patient's liver function before initiating treatment.

Under the new labeling information, prescribers will be required to check patients' liver function before prescribing fezonatant. If the transaminase level is found to be greater than or equal to 2 times the upper limit of normal (ULN), or the total bilirubin level is greater than or equal to 2 times the ULN, the patient should not start using this drug. In addition, for patients who have started taking the drug, the FDA recommends monthly liver laboratory testing for the first 3, 6, and 9 months. If during monitoring it is found that the transaminase level exceeds 5 times the ULN, or if the transaminase level exceeds 3 times the ULN and the total bilirubin level exceeds 2 times the ULN, medication should be stopped immediately. For patients with transaminase elevations exceeding 3 times the ULN, follow-up frequency should be increased and treatment should be discontinued promptly if any signs or symptoms of liver injury occur.

Symptoms of liver damage include new fatigue, decreased appetite, nausea, vomiting, itching, jaundice, pale stools, dark urine, and abdominal pain. This label update highlights the seriousness of the existing hepatotoxicity warning in the form of a boxed warning, emphasizing medical providers and patients' awareness of potential side effects, aiming to reduce the impact of related symptoms caused by menopause.

It should be noted that filazonatant is contraindicated in women with known cirrhosis, severe renal impairment, or end-stage renal disease, or women who are concurrently takingCYP1A2 inhibitors. The FDA's warning follows a notice it issued in September that felinatan may cause rare but serious liver damage. In reviewing a postmarketing report of a patient, the patient developed elevated liver function test values u200bu200band symptoms of liver injury approximately 40 days after taking fezonetan. Therefore, the FDA has also made new recommendations to increase the frequency of liver function testing, especially 2 months after starting medication, and periodic testing at 3, 6, and 9 months thereafter.

In May 2023, the FDA officially approved felinatan for the treatment of moderate to severe hot flashes caused by menopause. The approval was based on clinical trial results showing the safety and effectiveness of fellinetan. It is worth mentioning that filzonaitant is not a hormonal drug. Its mechanism is to bind and block the activity of neurokinin 3 receptors that affect brain temperature regulation.

The updated prescribing information clearly instructs patients to stop taking the medication immediately and contact the prescribing medical professional if they experience any signs and symptoms of liver damage. FDA pointed out that stopping the medication in time can prevent further worsening of liver damage and help liver function return to normal. This update not only emphasizes the importance of liver health, but also provides new recommendations for patients and healthcare professionals to ensure better monitoring and management of liver risks associated with filazonatin.

In summary, the updated labeling information for fezonatant is intended to increase the alertness of patients and physicians, promote safe medication practices, and ensure that patients are adequately monitored and protected while receiving treatment.

Reference materials:https://www.rheumatologyadvisor.com/news/boxed-warning-added-to-labeling-for-hot-flash-treatment-veozah/