Since the early 1990s, the incidence of diabetes type 2 has increased in children. This increase is most likely secondary to the rise in childhood obesity. The mean age of children that present with type 2 diabetes is 13.5 years old. Diabetes results from insulin deficiency and insulin resistance, a condition that decreases the effect insulin has on cells in the body. One of the most prescribed medications in kids and adults with type 2 diabetes is metformin (Glucophage).
Metformin was first synthesized back in the 1920s but was not seriously considered for use in treating diabetes until the 1950s. It took another 40 years for it to be released in the United States for treatment in type 2 diabetes. It is now first line treatment for diabetes as montherapy or concomitantly with insulin or sulfonylureas.
Metformin is the only antidiabetic medication still on the market that belongs to the drug class biguanides. It works by decreasing hepatic glucose production, improving insulin sensitivity and decreasing glucose absorption in the intestines. This leads to a reduction in fasting glucose levels by 60-70mg/dL, which in turn decreases hemoglobin A1c, a test that measures the average blood glucose over 2-3 months. Also of interest is that metformin has been evaluated in the treatment of polycystic ovarian syndrome and to help delay early menarche in females.
Metformin is available in an oral solution (Riomet), tablet (Glucophage) and extended release tablet (Fortamet, Glucophage XR, Glumetza). Metformin tablets and extended release tablets are available in generic.
The most common side effects during the beginning of treatment are headache, nausea, vomiting and diarrhea. These are usually transient and will stop after a few weeks of therapy. Taking doses with meals and starting with a low dose and increasing slowly should help decrease the likelihood of these adverse reactions. Kids often complain of the “fishy” or “sticky” odor associated with some of the generic tablets. Additional side effects include flushing, myalgia, rash, sweating and flu-like symptoms. Sometimes, the outer shell of the extended release tablets may be found in the stool.
Metformin has a black box warning for lactic acidosis. It is an extremely rare side effect but if it occurs it is a medical emergency. Because of this risk metformin should not be used in kids with renal or hepatic insufficiency. Symptoms of lactic acidosis can include anorexia, nausea, vomiting, belly pain, lethargy and decrease in blood pressure. The actual incidence is extremely low at around 9 incidences in 100,000 years of therapy.
Metformin can interact with many medications, so it is always best to check with the physician and pharmacist for drug interactions. Drugs that interact with metformin and are common in kids are cephalexin and corticosteroids.
Metformin has been approved in kids 10 years and older. Typical starting dose is 500mg twice daily. This can be increased to a maximum of 2000mg/day. Metformin will start working within a few days but maximum effect can take up to two weeks.
Along with lifestyle changes, metformin is a good option to treat type 2 diabetes in kids. It has been shown to help with weight loss in patients with diabetes and is one of the few antidiabetic medications that does that regularly cause hypoglycemia. Metformin is an inexpensive and effective way to help treat type 2 diabetes.