Drug Interactions between biotin / chromium picolinate / cinnamon and pramlintide

MONITOR: Pharmacologic dosages of chromium (200 mcg/day or more for adults) may help improve diabetic control and reduce the requirements for insulin and other antidiabetic agents. Chromium appears to play a role in normal insulin function and glucose utilization, and some investigators have suggested that it increases insulin sensitivity and glucose tolerance and decreases blood glucose levels in certain diabetics, possibly those with low chromium levels. However, others have not corroborated these findings, and a few have even reported a negative effect on glucose tolerance and blood levels.

MANAGEMENT: Until further data are available, therapy with pharmacologic dosages of chromium should be administered cautiously in patients receiving insulin or other antidiabetic agents. Patients should be monitored for changes in diabetic medication requirements.

MONITOR: Coadministration of cinnamon with antidiabetic drugs and/or insulin may have additive blood glucose-lowering effects, which may potentiate the risk of hypoglycemia. Cinnamon has been shown in vitro to increase glucose uptake, glycogen synthesis and insulin sensitivity. However, clinical data are conflicting. Some small studies have reported that cinnamon reduced fasting blood glucose levels and/or glycosylated hemoglobin (HbA1c) in patients with type 2 diabetes, whereas others have not. In a randomized control trial (RCT) in people with type 2 diabetes (n=60), it was reported that, compared to placebo, daily doses of 1 g, 3 g, or 6 g of oral cinnamon (as Cinnamomum cassia) consumed for 40 days reduced fasting blood glucose levels by 18% to 29%. In addition, an unblinded RCT in patients with poorly controlled type 2 diabetes managed in primary care in the USA (n=109) reported that the addition of oral cinnamon 1 g daily (as C. cassia) for 90 days to usual care reduced HbA1c by a statistically significant 0.83% compared to usual care alone, which lowered HbA1c by 0.37%. However, in a double-blinded, RCT in people with type 2 diabetes (n=57), compared to placebo, the administration of oral cinnamon 1 g daily (as C. cassia) for three months did not demonstrate significant differences in fasting blood glucose or HbA1c from baseline to three months. Hypoglycemia was not reported as an adverse effect in these studies.

MANAGEMENT: Until more information is available, blood glucose should be monitored if antidiabetic agents are used concomitantly with cinnamon. Patients should be advised on the potential signs and symptoms of hypoglycemia (e.g., headache, dizziness, drowsiness, nervousness, confusion, tremor, hunger, weakness, perspiration, palpitation, and tachycardia), how to treat it, and to contact their doctor if it occurs. Patients should also be advised to take precautions to avoid hypoglycemia while driving or operating hazardous machinery.