From the FDA Drug Label
You feel dizzy or lightheaded Lactic acidosis is a medical emergency and must be treated in a hospital Metformin hydrochloride, the medicine in metformin hydrochloride tablets, can cause a rare, but serious, side effect called lactic acidosis (a build-up of lactic acid in the blood) that can cause death.
The patient's complaint of dizziness and lightheadedness may be a symptom of lactic acidosis, a rare but serious side effect of metformin. Key points:
- The patient is taking 500mg metformin BID and has an A1C of <4.2.
- The patient has been instructed to hold metformin and continue with diet and exercise.
- A CBC will be checked to monitor for any adverse effects.
- The patient will be rechecked in 3 months to see if the dizziness changes and to recheck the A1C. 1
From the Research
I strongly recommend holding metformin and monitoring Debbra's dizziness and A1C levels, as her very low A1C of <4.2 while taking metformin 500mg twice daily suggests possible hypoglycemia that could be causing her dizziness and lightheadedness. Discontinuing metformin while maintaining diet and exercise is appropriate, with a follow-up in three months to reassess both symptoms and A1C. Additionally, obtaining a CBC is reasonable to evaluate for potential hematologic causes of dizziness, particularly since she's on medication for Ocular Cicatricial Pemphigoid, as discussed in 2. While her neurologist didn't believe the dizziness was neurologically related, and her eye doctor didn't attribute it to her ocular medication, hypoglycemia from metformin is a plausible explanation given her very low A1C. The plan appropriately addresses her primary concern about preventing falls while investigating the underlying cause. Her thyroid condition appears stable with recent ultrasound showing no new changes to nodules, which is reassuring as thyroid dysfunction could also contribute to dizziness symptoms.
Some key points to consider in Debbra's case include:
- The potential for hypoglycemia with metformin, especially given her low A1C, as metformin's effectiveness in preventing or delaying type 2 diabetes is well-documented in studies such as 3.
- The importance of monitoring her A1C levels and adjusting her treatment plan as necessary to prevent hypoglycemia and its associated risks.
- The need to evaluate for other potential causes of dizziness, including hematologic causes, given her medication for Ocular Cicatricial Pemphigoid.
- The stability of her thyroid condition, which reduces the likelihood that thyroid dysfunction is contributing to her dizziness symptoms.
Overall, the plan to hold metformin and monitor Debbra's dizziness and A1C levels is a reasonable and cautious approach, given the potential risks associated with hypoglycemia and the need to investigate other possible causes of her symptoms, as supported by the most recent and highest quality evidence available, including 3.