Medically reviewed by A Ras MD.
What is Riomet ER?
Riomet ER is a prescription medicine that contains metformin hydrochloride. Riomet ER is used with diet and exercise to help control high blood sugar (hyperglycemia) in adults and children 10 years of age and older with type 2 diabetes.
It is not known if Riomet ER is safe and effective in children under 10 years of age.
What is the most important information I should know about Riomet ER?
Riomet ER can cause serious side effects including:
Lactic acidosis. Metformin hydrochloride, the medicine in Riomet ER, can cause a rare, but serious side effect called lactic acidosis (a buildup of lactic acid in the blood) that can cause death. Lactic acidosis is a medical emergency and must be treated in the hospital.
Stop taking Riomet ER and call your healthcare provider right away if you get any of the following symptoms of lactic acidosis:
- feel very weak or tired
- have unusual sleepiness or sleep longer than usual
- have unusual (not normal) muscle pain
- feel cold, especially in your arms or legs
- have trouble breathing
- feel dizzy or lightheaded
- have unexplained stomach or intestinal problems with nausea or vomiting, or diarrhea
- have a slow or irregular heartbeat
You have a higher chance for getting lactic acidosis if you:
- have moderate to severe kidney problems. See “Who should not take Riomet ER?”
- have liver problems.
- have congestive heart failure that requires treatment with medicines.
- drink a lot of alcohol (very often or short-term “binge” drinking).
- get dehydrated (lose a large amount of body fluids). This can happen if you are sick with a fever, vomiting, or diarrhea. Dehydration can also happen when you sweat a lot with activity or exercise and do not drink enough fluids
- have certain x-ray tests with injectable dyes or contrast agents.
- have surgery.
- have a heart attack, severe infection, or stroke.
- are 65 years of age or older.
Tell your healthcare provider if you have any of the problems in the list above.
Tell your healthcare provider that you are taking Riomet ER before you have surgery or x-ray tests. Your healthcare provider may need to stop Riomet ER for a while if you have surgery or certain x-ray tests.
Riomet ER can have other serious side effects. See “What are the possible side effects of Riomet ER?”
Who should not take Riomet ER?
Do not take Riomet ER if you:
- have severe kidney problems.
- are allergic to the metformin hydrochloride or any of the ingredients in Riomet ER. See the end of this Patient Information guide for a complete list of ingredients in Riomet ER.
- have a condition called metabolic acidosis or diabetic ketoacidosis (high levels of certain acids called “ketones” in your blood or urine).
What should I tell my healthcare provider before taking Riomet ER?
Before taking Riomet ER, tell your healthcare provider about all of your medical conditions, including if you:
- have a history or risk for diabetic ketoacidosis. See “Who should not take Riomet ER?”
- have kidney problems.
- have certain x-ray tests with injectable dyes or contrast agents.
- are going to have surgery or other procedures for which you need to restrict the amount of food and liquid you eat and drink.
- have liver problems.
- have heart problems, including congestive heart failure.
- are 65 years or older.
- drink alcohol.
- are taking insulin or a sulfonylurea medicine.
- are pregnant or plan to become pregnant. It is not known if Riomet ER will harm your unborn baby. If you are pregnant, talk with your healthcare provider about the best way to control your blood sugar while you are pregnant.
- are a premenopausal woman who does not have periods regularly or at all. Riomet ER can cause the release of an egg from an ovary in a woman (ovulation). This can increase your chance of getting pregnant.
- are breastfeeding or plan to breastfeed. Riomet ER can pass into your breast milk. Talk with your healthcare provider about the best way to feed your baby while you take Riomet ER.
Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Know the medicines you take. Keep a list of them to show your healthcare provider and pharmacist when you get a new medicine.
Riomet ER may affect the way other medicines work, and other medicines may affect how Riomet ER works.
How should I take Riomet ER?
- Take Riomet ER exactly as your healthcare provider tells you.
- Use the Riomet ER specific dosing cup to measure your dose. Ask your pharmacist for a dosing cup if you do not have one.
- Riomet ER should be taken with your evening meals to help decrease an upset stomach.
- When your body is under some type of stress, such as fever, trauma (such as a car accident), infection, or surgery, the amount of diabetes medicine that you need may change. Tell your healthcare provider right away if you have any of these problems.
- Your healthcare provider should do blood tests to check how well your kidneys are working before and during your treatment with Riomet ER.
- Your healthcare provider will check your diabetes with regular blood tests, including your blood sugar levels and your hemoglobin A1c.
- Low blood sugar (hypoglycemia) can happen more often when Riomet ER is taken with certain other diabetes medicines. Talk to your healthcare provider about how to prevent, recognize and manage low blood sugar. See “What are the possible side effects of Riomet ER?”
- Check your blood sugar as your healthcare provider tells you to.
- Stay on your prescribed diet and exercise program while taking Riomet ER.
If you take too much Riomet ER, call your healthcare provider, or go to the nearest hospital emergency room right away.
What should I avoid while taking Riomet ER?
Do not drink a lot of alcoholic drinks while taking Riomet ER. This means you should not binge drink for short periods, and you should not drink a lot of alcohol on a regular basis. Alcohol can increase your chance of getting lactic acidosis. Also, don’t drink alcohol at the same time you take Riomet ER because it can speed up how fast the medicine gets into your body.
What are the possible side effects of Riomet ER?
Riomet ER may cause serious side effects, including:
- See “What is the most important information I should know about Riomet ER?”
- Low vitamin B12 (vitamin B12 deficiency). Using Riomet ER may cause a decrease in the amount of vitamin B12 in your blood, especially if you have had low vitamin B12 levels before. Your healthcare provider may do blood tests to check your vitamin B12 levels.
- Low blood sugar (hypoglycemia). If you take Riomet ER with another medicine that can cause lower blood sugar, such as a sulfonylurea or insulin, your risk of getting low blood sugar is higher. The dose of your sulfonylurea medicine or insulin may need to be lowered while you take Riomet ER. Signs and symptoms of low blood sugar may include:
- fast heartbeat
- shaking or feeling jittery
Common side effects of Riomet ER include:
- nausea and vomiting
- stomach-area (abdominal) discomfort
- gassiness (flatulence)
- weakness or lack of energy (asthenia)
These are not all the possible side effects of Riomet ER. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
General information about the safe and effective use of Riomet ER
Medicines are sometimes prescribed for purposes other than those listed in a Patient Information guide. Do not use Riomet ER for a condition for which it was not prescribed. Do not give Riomet ER to other people, even if they have the same symptoms that you have. It may harm them.
You can ask your pharmacist or healthcare provider for information about Riomet ER that is written for health professionals
How should I store Riomet ER?
- Store at room temperature between 68°F to 77°F (20°C to 25°C) in the original bottle.
- Throw away (discard) any unused portion of the mixed (reconstituted) suspension in the household trash after 100 days.
Keep Riomet ER and all medicines out of the reach of children
What are the ingredients in Riomet ER?
Active Ingredient: metformin hydrochloride
Inactive Ingredients: carboxymethyl cellulose sodium, colloidal silicon dioxide, dibutyl sebacate, ethyl cellulose, hypromellose, magnesium stearate, methyl paraben, microcrystalline cellulose, propyl paraben, sucralose, strawberry flavor Type FL # 28082 (flavoring ingredients, propylene glycol and glycerin) xanthan gum and xylitol.
For more information call 1-800-818-4555.
Instructions of use for Riomet ER
Riomet (ree oh met) ER
for extended-release oral suspension
Read this Instructions for Use for Riomet ER before you start taking it and each time you get a refill. There may be new information. This leaflet does not take the place of talking to your healthcare provider about your medical condition or treatment.
Important information: Check the expiration date printed on the bottle. Do not use if the expiration date has passed or if the bottle appears damaged or defective. See Figure A.
Step 1. Shake the bottle well for at least 10 seconds before each use. See Figure B.
Step 2. Remove the child-resistant cap (push down and turn) from the bottle.
Push down and turn the cap in the direction of the arrow as shown in Figure C.
Step 3. Pour your prescribed dose in the Riomet ER dosing cup provided by your pharmacist and take by mouth. See Figure D.
Step 4. Close the bottle with the child-resistant cap by turning the cap clockwise. See Figure E.
Step 5. Clean the Riomet ER dosing cup with water only after each use and store in the box.
Step 6. Throw away (dispose of) any unused portion of the mixed (reconstituted) suspension medicine in the household trash after 100 days.
How to store Riomet ER
- Store Riomet ER at room temperature between 68° F to 77° F (20° C to 25° C) in the original bottle.
- Keep Riomet ER and all medicines out of the reach of children.
SRC: NLM .