Publication Date: 12/30/2005
Remember that the information presented here is not intended to replace the care of your own doctor. Before making any changes in the management of your own illness, you should consult your physician or other qualified medical professionals.
Question
I take metformin twice per day and have always taken it after a meal. However, I was recently in the hospital, and the doctor there told me I should take it 30 minutes before a meal, and the pharmacist says with a meal. What is the proper time to take the medication?Answer
The U.S. label [PDF file] is vague. For the short-acting form (Glucophage), the label states:The usual starting dose of GLUCOPHAGE (metformin hydrochloride tablets) is 500 mg twice a day or 850 mg once a day, given with meals.For the long-acting form (Glucophage XR), it states:
The usual starting dose of GLUCOPHAGE XR (metformin hydrochloride extended-release tablets) is 500 mg once daily with the evening meal. Dosage increases should be made in increments of 500 mg weekly, up to a maximum of 2000 mg once daily with the evening meal.Since the drug's mode of action is quite slow in onset, I'd think the main concern would be what time, relative to when you eat, that would be least likely to cause gut side effects (such as nausea or diarrhea). Whatever you have been doing, if it's not causing gut side effects, continue with it!
