From the FDA Drug Label
5.1 Risk of Thyroid C-Cell Tumors In both sexes of rats, tirzepatide caused a dose-dependent and treatment-duration-dependent increase in the incidence of thyroid C-cell tumors (adenomas and carcinomas) in a 2-year study at clinically relevant plasma exposures [see Nonclinical Toxicology (13. 1)]. It is unknown whether MOUNJARO causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as human relevance of tirzepatide-induced rodent thyroid C-cell tumors has not been determined. MOUNJARO is contraindicated in patients with a personal or family history of MTC or in patients with MEN 2 Counsel patients regarding the potential risk for MTC with the use of MOUNJARO and inform them of symptoms of thyroid tumors (e.g., a mass in the neck, dysphagia, dyspnea, persistent hoarseness). Routine monitoring of serum calcitonin or using thyroid ultrasound is of uncertain value for early detection of MTC in patients treated with MOUNJARO. Such monitoring may increase the risk of unnecessary procedures, due to the low test specificity for serum calcitonin and a high background incidence of thyroid disease Significantly elevated serum calcitonin values may indicate MTC and patients with MTC usually have calcitonin values >50 ng/L. If serum calcitonin is measured and found to be elevated, the patient should be further evaluated. Patients with thyroid nodules noted on physical examination or neck imaging should also be further evaluated.
The patient's low TSH and elevated CA-125 while on Mounjaro (tirzepatide) may indicate a potential issue with thyroid function.
- Key points to consider:
- Mounjaro has been associated with an increased risk of thyroid C-cell tumors in animal studies.
- The drug label recommends counseling patients on the potential risk of medullary thyroid carcinoma (MTC) and informing them of symptoms of thyroid tumors.
- Routine monitoring of serum calcitonin or thyroid ultrasound is of uncertain value for early detection of MTC.
- Significantly elevated serum calcitonin values may indicate MTC. Given the uncertainty surrounding the relationship between Mounjaro and thyroid function, it is essential to closely monitor the patient's thyroid function and investigate any symptoms or abnormalities that may indicate a thyroid issue 1.
From the Research
If you have low TSH, elevated CA-125, and are taking Mounjaro (tirzepatide), you should consult your healthcare provider promptly as these findings require medical evaluation. Low TSH may indicate hyperthyroidism, which needs proper diagnosis and treatment with medications like methimazole or propylthiouracil 2. Elevated CA-125 is a tumor marker that can be associated with ovarian cancer but also with benign conditions like endometriosis or pelvic inflammatory disease, requiring further investigation through imaging and possibly biopsy. Mounjaro is a GLP-1/GIP receptor agonist used for type 2 diabetes and weight management, and while it generally doesn't directly affect thyroid function or CA-125 levels, medication interactions are possible 3. Your doctor may need to adjust your Mounjaro dosage or other medications based on your thyroid status. These conditions should be evaluated separately but considered together, as thyroid dysfunction can sometimes affect CA-125 levels and diabetes management. Don't stop taking Mounjaro without medical advice, but do schedule an appointment for comprehensive testing including thyroid panel, imaging studies, and possibly referral to specialists in endocrinology and gynecology or oncology 4, 5, 6.
Some key points to consider:
- Clinical reasoning is an important skill that enables health care professionals to identify and evaluate patients' real or potential problems, implement appropriate interventions, solve clinical problems, and improve the quality of health care and patient outcomes 4.
- Effective communication is fundamental to advanced practice, and nurses can take various approaches to develop their clinical reasoning and communication skills 6.
- A comprehensive guide to undertaking patient consultations, physical examination, and diagnostic reasoning on a body systems basis is essential for healthcare professionals 3.
- Collaborative processes grounded in theory have proven to be the most successful when seeking to optimize healthcare team communication 5.
It is crucial to prioritize medical evaluation and consultation with a healthcare provider to address the potential risks associated with low TSH, elevated CA-125, and Mounjaro use.