Metformin is a form of diabetes medication that is intended to be used as a portion of your medical care. In most cases, metformin is not used alone, but in addition to insulin therapy and other medications to help keep your blood sugar stable. A reaction to metformin in regular patients is rare, though the risk does increase in certain groups. Your doctor will be able to inform you about your risk and what to do to help avoid these conditions from developing.
Indications and Usage
Metformin can be sold under the names Glucophage or Glucophage XR. You may also see this drug labeled as Fortamet, Riomet or Glumetza. This medication is commonly used alongside other medications such as insulin to treat type II diabetes. This drug will help to regulate the amount of sugar in the bloodstream to decrease the amount of sugar you absorb through the liver. The medication will also increase your body's response to any insulin you may be taking to help control the amount of glucose in your bloodstream. Metformin is not intended to be used to treat type I diabetes.
Your metformin prescription may come in tablet, extended-release tablet or liquid form. All forms will be taken orally. Liquid and extended-release tablets will be taken once a day while standard tablets may be taken 2-3 times each day. Try to take your prescription around the same time every day, and with food to help your body absorb the medication fully. Tablets should not be crushed, chewed or split. You should not increase your dosage without your doctor's consent.
Metformin Dosage
The average adult will usually include 2000 mg, which may be taken in single or divided doses. In most cases, patients will start with a lower dose, often below 1500 mg per day, which will be increased in three month intervals. Patients are usually given 850 mg tablets to be taken as a single dose when they are not working with extended release tablets or liquid. This will allow your doctor to better monitor your condition and adjust your dosage as necessary to build up a tolerance.
The maximum daily dosage for metformin should not exceed 2550 mg per day. Any doses that are given at this level should be divided to at least three doses throughout the day. These must be taken with food in order to prevent a reaction. The minimum effective dose of metformin in adults is two 500 mg tablets a day.
Children between the ages of 10 and 16 should not take more than 2000 mg per day of metformin. Those who are younger will be started on a regimen of 500 mg doses divided weekly, which can slowly be increased to this level. It should be noted that the effectiveness and safety of using metformin to treat children under the age of 10 has not firmly been established with current research.
Pregnant women have not been shown to be at risk while taking metformin. If you are currently monitoring your diabetes using other medications, then risk is no different than what it would be if you were to add metformin to your routine. Using this drug has not been shown to endanger the growing fetus, though there was some transference of the drug to the infant and placenta. It has been found that pregnant women had an easier time using metformin when it was injected rather than taken orally.
Doses of metformin are directly related to the renal function of the patient. For this reason, it is important to have your liver and kidney function monitored regularly to determine how well the medication is taking effect. Those who suffer from liver or kidney disease, or those who are malnourished may need to have their dosage of metformin adjusted or eliminated in order to avoid developing side effects. Elderly patients will also start on a significantly decreased dose to help avoid some of the same side effects. Talk with your doctor about your potential risk before starting your prescription.
Metformin Side Effects
Side effects for metformin often become less severe and less common as the patient adjusts their dosage and continues taking the medication. The most common side effects include decreased appetite, fever, general discomfort, difficulty urinating, sleepiness, lower back pain or cough. In many cases, this reaction is due to your body getting used to a lower blood sugar level in the blood stream. Check your condition regularly and do what you can to keep your blood sugar level stable to help avoid these side effects. If side effects persist, talk to your doctor about how to proceed. Do not stop taking your medication unless you are given instruction to do so.
Less common side effects include blurred vision, dizziness, feeling of warmth, headache, increased hunger, nightmares, slurred speech, nervousness, redness, shakiness or tightness to the chest. While these side effects are rare, they could be a sign that you are developing a more serious condition. Talk to your doctor about any side affects you develop to ensure that you are taking your medication at a proper level. If you ever feel like your side effects are becoming life threatening, contact emergency medical services for assistance.
In extremely rare cases patients reported behavioral changes similar to intoxication, difficulty concentrating, lack of strength or restless sleep. These often went away as the patient became used to the medication. If you have had similar experiences with other diabetes medication, do not drive or operate machinery until you are sure you will not have a poor reaction to metformin. Like any other side effects, inform your doctor about your condition and decide together about the best way to proceed.
If you do not take metformin as instructed you may be at risk for overdosing. If you begin to experience extreme nausea, vomiting, abdominal pain or diarrhea you could be dealing with an overdose. Regular overdosing could also lead to the development of lactic acidosis in the patient. If you feel as though you may be suffering from an overdose, check your blood for the medication level and talk to your doctor about how to proceed. If at any time you start to develop abnormal heartbeat, rapid breathing, fainting, sweating or dizziness seek out emergency care as soon as possible.
Seniors and those with liver or kidney disease are at a much higher risk for having an overdose than other patients. They are also much more likely to develop lactic acidosis from their medication. In order to avoid this, doctors will usually keep doses for these patients low and avoid using extended release medications.
If you are pregnant and using metformin to treat polycystic ovary disease, there is a much better chance for healthy pregnancy. In laboratory tests, women using this drug saw a much lower rate for miscarriage. Your doctor may transfer you to this medication and a strict diet to help avoid the side effects that are associated with insulin treatments during pregnancy.
Patients with liver or kidney problems should have their renal function constantly monitored while on metformin. It is possible to develop lactic acidosis while on this medication, which can cause severe damage to the body.
Interactions
Tell your doctor about any other medications you are taking to treat your diabetes before starting on metformin. If you are taking Glyburide or Furosemide you may have trouble clearing your dose and may be at a higher risk to develop side effects from these or your metformin prescription. Those taking nifedipine alongside your prescription may at risk for excreting your prescription in your urine rather than absorbing it. Cationic drugs can disrupt renal function in patients taking metformin, which can increase the chance of side effects or the development of lactic acidosis.
You may not be able to take other diuretics, corticosteroids, thyroid products, estrogen, nicotinic acid or other products that produce hyperglycemia while on metformin. Inform your doctor about any medications or substances you take regularly to help avoid developing a reaction. You may also need to avoid salicylates, chloramphenicol or sulfonamides because metformin binds itself to plasma proteins.