Discontinue Mounjaro Immediately
A patient with an A1C of 4.8% taking Mounjaro should have this medication discontinued immediately, as this A1C level is far below any therapeutic target and indicates no diabetes diagnosis, creating unnecessary risk of hypoglycemia, adverse effects, and cost without any clinical benefit. 1
Immediate Action Required
- Stop Mounjaro now - An A1C of 4.8% is well below the 6.5% threshold recommended by the American College of Physicians for deintensifying therapy, and continuation provides zero benefit while exposing the patient to medication risks 2, 1
- This A1C level (4.8%) is in the normal, non-diabetic range (normal A1C is <5.7%), meaning there is no diabetes to treat 1
- The American Diabetes Association guidelines state there is no need to maintain therapy when A1C is between 6-7% in low-risk patients, and 4.8% is dramatically lower than even this range 2
Diagnostic Workup Needed
Before simply accepting this A1C as accurate, investigate potential causes of falsely low readings:
- Check for conditions affecting red blood cell turnover: hemolytic anemia, recent blood transfusion, glucose-6-phosphate dehydrogenase deficiency, iron deficiency anemia, or use of erythropoietin-stimulating agents 2, 1, 3
- Obtain fasting plasma glucose to verify actual glucose status independent of A1C 1
- Consider continuous glucose monitoring (CGM) for 14 days to assess true glycemic patterns, as A1C can be misleading in individual patients 2, 4
- Review for hemoglobin variants that could affect A1C accuracy 2
If True Hypoglycemia Confirmed
Should the low A1C reflect actual low glucose levels (which would be unusual but possible):
- Evaluate for insulinoma or other insulin-secreting tumors 1
- Assess for adrenal insufficiency or other endocrine disorders causing hypoglycemia 1
- Screen for malnutrition or eating disorders 1
- Review all medications that could contribute to hypoglycemia (beta-blockers, quinolones, etc.) 1
Follow-Up Strategy
- Recheck A1C in 3 months only if there is concern about temporal trends or if investigating causes of the abnormal reading 1
- If A1C remains <5.7% without any diabetes medications, no diabetes diagnosis exists and routine diabetes monitoring is unnecessary 1
- The patient should not be labeled as diabetic or treated as such with this A1C level
Key Clinical Pitfall to Avoid
The most critical error here would be continuing Mounjaro "just to be safe" or because the patient was previously diagnosed with diabetes. No trial has ever shown benefit from targeting A1C levels below 6.5%, and the ACCORD trial was actually stopped early due to increased mortality when targeting A1C <6.5% 2. At 4.8%, you are exposing this patient to medication burden, cost, and potential adverse effects (including gastrointestinal side effects common with GLP-1 receptor agonists like Mounjaro) with absolutely no evidence of benefit 2, 1.