Metformin

Metformin is a medication that has been shown to help prevent weight gain in patients who take neuroleptic mood stabilizers, which may cause weight gain in some patients.

Isn’t metformin a medication for diabetes? 
Metformin is considered a first line treatment for type 2 diabetes. But it also shows considerable benefit in helping to prevent weight gain in patients who are started on atypical antipsychotics, which are down to cause weight gain as a side effect. 

Is metformin safe in children? 
Yes, it has been studied in children and teenagers who are on neuroleptic mood stabilizers (also called atypical antipsychotics) and it has been shown to safely prevent weight gain. In fact, the group on metformin did better emotionally as well, so there are likely secondary benefits of metformin on mood.

How is metformin dosed? 
For most ages we start at 500mg “BID” (2x per day), taken with breakfast and dinner. It can cause some GI upset so it’s best taken with food. 
The goal dose is usually 1000mg BID for those 14 and older. 
For those < 14 we start at 500mg daily and then 7 days later, add an evening dose. 

What should be taken along with metformin due to absorption concerns? 
When taking metformin, you should also take a Vitamin B12 supplement, because metformin has been shown to lead to Vitamin B12 deficiency in up to 13% of people who take it. Here is a great brand (500mcg dose)-- take as directed on the bottle.

What are the main side effects of metformin? 
It’s usually very well tolerated but GI issues can include nausea, cramps, diarrhea, flatulence, and in rare cases, vomiting. This can be minimized by starting at lower doses and taking with food. For most, it gets better with time as the body gets used to metformin.

Who cannot take metformin? 
Those with kidney disease and low glomerular filtrate rate (GFR < 30) because that increases the risk of metabolic acidosis.

What is the mechanism of metformin? 
-Decreases glucose production by the liver 
-Increases insulin receptors which increases insulin sensitivity (the opposite of type-2 diabetes) "-Increases the secretion of growth differentiating factor, which reduces appetite 

How long has metformin been around? 
Metformin was first synthesized in the 1920’s based off of research that synthesized the medication based off of Goats-rue, or French Iliac plant. It was shown to lower blood glucose in rabbits in the 1920’s but didn’t become a medication used in people until the 1950’s. 

What are the metabolic benefits of metformin? 
-Decrease glucose dysregulation (increasing insulin sensitivity) 
-Decreasing weight and waist circumference 
-Decrease triglycerides 
-Decrease the risk of obesity 
-Decreasing weight gain when on atypical antipsychotics 

What are the non-metabolic benefits of metformin? 
-Lowers serum prolactin (which his elevated by select antipsychotics including risperidone)
-Promotes neurogenesis in the brain 
-Improved cognition 
-Counteract the blunting effects that may occur with some atypical antipsychotics
-Lowers anxiety by increasing serotonin concentration & activity
-Improving fertility in women with PCOS 
-Has many anti-aging properties and increases life longevity 
-Antiinflammatory benefits and can help lower the impact of IBD, osteoporosis, neurodegeneration, and frailty 
-In the IMPACT study of children and teenagers on atypical antipsychotics, those put on metformin showed more improvement in their irritability than those put on a placebo.