Special Guest Blog from Kristen Komaiko, PharmD, PGY Resident, St. Louis College of Pharmacy. Development of this blog post was supported by a grant from AHRQ [Lipman/1 R18 HS021952-01].
Metformin is the initial drug of choice that most clinicians choose for patients with newly diagnosed diabetes because of good tolerability and guidelines that sing its praises. Metformin has been shown to have several potential advantages: it is affordable and available generically, lowers A1c, reduces incidence of hypoglycemia, reduces fasting plasma glucose, does not have many drug to drug interactions, patients remain weight neutral or experience modest weight loss, decreases plasma triglycerides and LDL-C, increases plasma HDL, and it is the only oral antihyperglycemic medication proven to reduce the risk of total mortality by way of decreased macrovascular complications. It’s no wonder healthcare providers love this drug! There is no single drug that matches its combination of safety, efficacy, cost effectiveness, and the spectrum of positive clinical improvements.
However, it’s not appropriate for all people with diabetes. Contraindications can include patients who have previously had a hypersensitivity reaction to metformin, patients with renal dysfunction, those at risk for lactic acidosis (acute or unstable congestive heart failure), dehydration, excessive alcohol intake, hepatic or renal impairment, sepsis, or any hypoxemic state), and should not be initiated in patients over 80 years old unless normal renal function is established.
So you might wonder, what about initial drug therapy for patients with contraindications to metformin? Although there are no wrong choices for initial drug therapy, each patient has unique circumstances and therapeutic plans that need to be considered. When choosing a drug therapy, a goal-oriented approach is what we should strive for, meaning the intervention should be in relation to the distance from the goal. Algorithms can be helpful, but the ultimate drug choice should depend on the patients. Diabetes educators have to consider a number of factors, including: BMI, risk of weight gain, duration of diabetes, adverse effect profile, risk for hypoglycemia, acceptance of injection therapies, contraindications, comorbidities, A1c goals, fasting plasma glucose (FPG), postprandial plasma glucose (PPG), and exercise levels.
These factors come into play because different drugs have different responses. So for example, some drugs are better for improving FPG versus PPG, while other drugs can improve lipid profiles. Additionally, a patient’s lifestyle choices can make a difference. We all know exercise can improve insulin sensitivity and stimulate weight loss. As far as A1c goals and drug therapy selection, some issues to think about are age, dementia, life expectancy, depression, osteoporosis, and other conditions where select medications may be poor choices.
While I gave you some ideas on how to select an alternative drug treatments to metformin, click here for some guidance on actual drug therapy options.