Metformin is a biguanide and antidiabetic drug used to treat Type 2 Diabetes. Its action is to decrease hepatic glucose production and decrease intestinal glucose absorption. This drug should be taken to help lower the amount of glucose made and absorbed in order to keep glucose levels within normal limits. It also increases the sensitivity to insulin and helps maintains blood glucose. Metformin is contraindicated in: hypersensitivities, metabolic acidosis, dehydration, sepsis, hypoxemia, hepatic impairment, acute or chronic alcohol excessively used, renal dysfunction, radiographic studies requiring intravenous iodinated contrast media, or congestive heart failure (Davis Drug Guide, n.d.). Serious adverse reactions and side effects that can occur from taking Metformin are: abdominal bloating, diarrhea, nausea, and vomiting, along with unpleasant metallic taste, hypoglycemia, and decreased vitamin B12 levels (Davis Drug Guide, n.d.). There are several drugs and natural products can interact with Metformin, which can inhibit its therapeutic effects such as alcohol and iodinated contrast media, as well as other drugs and natural products. Unfortunately, there is no antidote for overdose. Treatment for toxicity is mainly supportive measures to restore normal acid-base levels, remove the absorbed metformin, and support of cardiovascular function (Sawyer, Spiller, 2006).
Pharmacology Essay: Metformin
Metformin is an biguanide and antidiabetic drug used to treat Type 2 Diabetes. This drug can be used alone or in conjunction with insulin to treat Type 2 Diabetes (MedlinePlus, 2018). There are two different types of Diabetes Mellitus: insulin dependent and insulin resistant. Metformin is specifically for insulin resistant diabetes and should not be taken for insulin dependent diabetes. Insulin dependent diabetes, also known as Type 2 Diabetes, is a metabolic disorder that causes the body to improperly use insulin (American Diabetes Association, n.d.). At first, the pancreas will make too much insulin. Eventually, the pancreas will tire, and glucose levels will not be within a normal limit because the pancreas will not be able to make enough insulin (American Diabetes Association, n.d.). Symptoms of Type 2 Diabetes include: high blood pressure, increased blood glucose levels, neuropathy, increased thirst, fruity breath, and other serious complications.
Metformin is indicated in the management of Type 2 diabetes mellitus and may be used with diet, insulin, or sulfonylurea oral hypoglycemics (Davis Drug Guide, n.d.) Its action is to decrease hepatic glucose production and decrease intestinal glucose absorption. Metformin helps to lower the amount of glucose made and absorbed in order to keep glucose levels within normal limits. This drug also increases the sensitivity to insulin and helps maintains blood glucose.
Metformin should not be taken for the following reasons: hypersensitivities, metabolic acidosis, dehydration, sepsis, hypoxemia, hepatic impairment, acute or chronic alcohol excessively used, renal dysfunction, radiographic studies requiring intravenous iodinated contrast media, or congestive heart failure (Davis Drug Guide, n.d.). Taking Metformin with any of these conditions could result in serious complications such as fatality. Patients should be educated to use Metformin cautiously in the following: concurrent renal disease, geriatric or debilitated patients, chronic alcohol use or abuse, serious medical conditions such as heart attacks or strokes, infection, patients undergoing surgical procedures, hypoxia, pituitary deficiency or hyperthyroidism, pregnancy, lactation, and children under the age of ten years old (Davis Drug Guide, n.d.).
There are several serious adverse reactions and side effects that can occur from taking Metformin. Some responses that occur most often are: abdominal bloating, diarrhea, nausea, and vomiting (Davis Drug Guide, n.d.). Other less serious side effects may be unpleasant metallic taste, hypoglycemia, and decreased vitamin B12 levels (Davis Drug Guide, n.d.). Lactic acidosis is a very serious, but rare, adverse effect that occurs when there is a buildup of lactic acid in the bloodstream (MedlinePlus, n.d). Lactic acidosis is a life-threatening adverse effect of Metformin and the patient should be educated and monitored for side effects of this extremely severe condition.
Several drugs and natural products can interact with Metformin, which can inhibit its therapeutic effects. Ingestion of alcohol or iodinated contrast media may increase the risk for lactic acidosis. Several drugs that may compete for elimination pathways with Metformin are Amiloride, Digoxin, Morphine, Procainamide, Quinidine, Rantidine, Triamterene, Trimethoprim, calcium channel blockers, and Vancomycin which may cause altered responses (Davis Drug Guide, n.d.). Medications such as Cimetidine and Furosemide can increase the effects of Metformin, along with Nifedipine which can also increase absorption (Davis Drug Guide, n.d.). Glucosamine, a natural product, can worsen blood glucose control, which to some patients can seem contradictory to taking Metformin. Another natural product that can affect glucose levels are Chromium and Coenzyme Q-10, which may increase hypoglycemic effects.
Chronic therapy of Metformin carries a small but significant chance of acquiring lactic acidosis. The primary risk factor for lactic acidosis are issues with the kidneys or an illness that leads to hypoxemia or renal failure (Sawyer, Spiller, 2006). Acute therapy toxicity of Metformin may exhibit symptoms such as abdominal pain, diarrhea, or vomiting. Other symptoms are secondary to lactic acidosis. Some of these symptoms include: altered mental status, tachypnea, hypotension, hypothermia, ventricular dysrhythmia, decreased cardiac output, shock, and death (Sawyer, Spiller, 2006). Lactic acidosis can take four to eight hours to become apparent and can persist for up to forty-eight hours after ingestion. Treatment of Metformin overdose is mainly supportive measures. Most attempts are to restore normal acid-base levels, removal of the absorbed metformin, and support of cardiovascular function (Sawyer, Spiller, 2006). Unfortunately, there is no specific antidote for Metformin overdose. One supportive measure used to absorb Metformin and inhibit further absorption is activated charcoal. In order to correct acidosis, infusions of sodium bicarbonate have also been found to be helpful (Sawyer, Spiller, 2006).
Metformin is very helpful in decreasing glucose production and absorption in those with Type 2 Diabetes. This drug should not be taken in people with renal impairment or at risk for lactic acidosis, the most serious complication. It has some interactions with drugs and natural drug products (Davis Drug Guide, n.d.). Toxicity and overdose of the drug can only be treated with supportive measures since there is currently not an antidote to reverse the effects of overdose (Sawyer, Spiller, 2006). This drug is helping an abundance of people regulate their glucose levels in order to prevent future complications related to Diabetes Mellitus.