Metformin 500mg Tablets
PACKAGE INSERT - Patient Information Leaflet
Metformin 500mg Tablets and Metformin 850mg Tablets
Metformin hydrochloride Metformin hydrochloride
What you should know about Metformin Tablets
Please read this leaflet carefully before you start to take these tablets. Keep it until all the prescribed course of Metformin Tablets has been finished, as you may want to read it again. This leaflet may not contain all the information about this medicine that you would like to know, so please ask your doctor or pharmacist if you have any questions.
What is in your medicine?
Each Metformin tablet contains either 500 or 850 mg of the active ingredient metformin hydrochloride, together with some other ingredients. These are included to aid the manufacture of the tablets, to make them easier to swallow and to help them disperse in your stomach. These other ingredients are sodium starch glycollate, maize starch, povidone, colloidal anhydrous silica, magnesium stearate, hypromellose, titanium dioxide (E171), propylene glycol, macrogol 6000 and purified talc.
Metformin Tablets are available in blister packs of 84 (500 mg) tablets and 56 (850 mg) tablets.
Metformin hydrochloride is one of a group of medicines called oral hypoglycaemics, which work by reducing the level of sugar in the blood.
Marketing authorization holder:
8PM Chemist Limited. 61 Wolverhampton Street. Willenhall, West Midlands. WV13 2NF Manufacturer:
Dragenopharm Apotheker Piischl GmbH & Co. KG. Gdllstrasse 1. D - 84529 Tittmoning, Germany.
What are Metformin Tablets for?
Metformin Tablets are for the treatment of a type of diabetes which usually only occurs in adults and is not severe enough to need insulin but which does not respond to dietary measures alone.
Before taking your medicine
Make sure that it is safe for you to take Metformin Tablets. If you answer YES to any of the following questions, or are not sure, tell your doctor or pharmacist:
• Are you allergic to any of the ingredients in this medicine?
• Do you drink alcohol?
• Have you ever fainted or even suffered a coma from having diabetes?
• Do you have any problem with your liver or kidneys?
• Do you have a heart disorder including heart failure and recent heart attacks ?
• Are you, or could you be. pregnant?
• Are you breast-feeding?
• Do you have any problems with your circulation causing, for example, frequent cramp in your calves or leg ulcers that do not heal?
• Do you have a fever or are you unwell in any other way?
• Are you on a special diet?
• Are you taking other antidiabetic drugs (e.g. insulin, guar gum or a sulphonylurea drug)?
• Are you suffering from an excessive loss of body water?
• Do you have breathing problems?
If your are scheduled to have surgery under general anaesthesia, you should tell your doctor that you are taking Metformin Tablets. Your doctor will instruct you to stop taking Metformin Tablets before, during and after the surgery.
Medical tests or examinations that use certain medicines called contrast agents, with x-rays, may cause less urine output than usual. Passing unusually low amounts of urine may increase the chance of a build-up of metformin hydrochloride and unwanted effects. Therefore, tell your doctor that you are taking these tablets prior to any medical tests as they may need to be stopped before you have the tests. They can be restarted 48 hours after the tests if your kidneys are found to be functioning normally.
Patients who are already on insulin should only be started on a course of treatment with these tablets in hospital. Metformin Tablets should not be taken by children._
You should not drink alcohol whilst you are being treated with Metformin Tablets. Other drugs, including some you can buy without a prescription, may interact with these tablets. If you are taking or intend to take any other medicine during treatment with Metformin Tablets, check with your doctor or pharmacist that it is safe to do so. This is particularly important in the case of
• anti-inflammatory painkillers such as salicylates or pyrazolones
• medicines for depression or psychoses such as MAO inhibitors and phenothiazines
• oxytetracycline
• medicines for high blood pressure such as ACE inhibitors, beta blockers, diazoxide, clonidine and guanethidine
• thiazides and loop diuretics (water tablets)
• medicines for lowering cholesterol levels in the blood such as clofibrate and nicotinic acid
• cyclophosphamide
• hormones including the contraceptive “piir, steroids, thyroid hormones
• glucagon - you may have received this as an injection for a hypoglycaemic attack as a consequence of your diabetes
• adrenaline and other similar drugs which you would generally be administered in hospital
• cimetidine
• tablets that thin the blood such as phenprocoumone
The other ingredient “propylene glycol" may cause allergic reactions.
Metformin Tablets on their own should not affect your ability to drive, but if you are also taking any other medicines which lower the blood sugar it is possible that their combined effects could make you feel faint, dizzy, weak or jittery. If this happens you should not drive or operate any machinery until you have recovered.
Taking your medicine
Your doctor or pharmacist will have told you about this, and you should always follow their instructions carefully. Treatment usually starts with a dose of one 500mg tablet three times a day or one 850mg tablet twice a day. Your doctor may then increase the dose in a stepwise manner until the right dose for you is found. After a while your doctor may then be able to reduce the dose. The dose needed varies a lot between different people and some patients may require as little as one 500 mg tablet each day. The maximum doses are six 500 mg tablets or three 850 mg tablets daily. The tablets should be taken with a glass of water during or after meals. Do not chew the tablets but swallow them whole.
If you miss a dose, take it as soon as you remember unless it is nearly time for the next dose. Never double-up on the next dose to make up for the one missed.
If you swallow too many tablets or someone else accidentally takes your medicine, contact your doctor, pharmacist or nearest hospital straight away.
While taking your medicine
Any medicine can have side-effects. Metformin Tablets are usually well tolerated, but sometimes they can cause stomach upsets such as nausea, vomiting, abdominal pain, diarrhoea, loss of appetite or a metallic taste. If such side-effects do occur, they often get better spontaneously so you should continue to take the tablets unless:
• your stomach upset is severe or shows no sign of getting better after a few days - in this case contact your doctor
• you also develop muscle pains, breathing problems, confusion or drowsiness - in this case you must contact your doctor immediately or go to the nearest hospital accident and emergency department since these symptoms may indicate the uncommon but serious condition of lactic acidosis.
Rarely, skin reactions may occur. If you notice a rash ask your doctor for advice about continuing with the tablets.
Prolonged treatment with metformin hydrochloride can deplete reserves of vitamin Bi2 and this may cause anaemia. Regular blood tests for kidney function and vitamin B12 should therefore be carried out.
If you think you have any other side-effect from taking this medicine, please tell your doctor or pharmacist.
How to store your medicine
• Do not take the tablets after the expiry date on the label.
• Do not store the tablets above 25°C.
• Keep all medicines out of the reach and sight of children - preferably in a locked cupboard or medicine cabinet.
Remember
This medicine is only for the person to whom it is dispensed. It should not be given to other people even if their symptoms are the same, as it may harm them.
Date leaflet last revised: October 2001