Riomet ER Side Effects
Generic name: metformin
Medically reviewed by Drugs.com. Last updated on Oct 6, 2022.
Note: This document contains side effect information about metformin. Some dosage forms listed on this page may not apply to the brand name Riomet ER.
Applies to metformin: oral solution, oral suspension extended release, oral tablet, oral tablet extended release, oral tablet extended release 24 hr.
Oral route (Tablet; Tablet, Extended Release; Solution; Suspension, Extended Release)
Death, hypothermia, hypotension, and resistant bradyarrhythmias have been reported due to metformin-associated lactic acidosis. Onset may be subtle and include nonspecific symptoms such as malaise, myalgia, respiratory distress, somnolence, and abdominal distress; laboratory abnormalities include low pH, increased anion gap and elevated blood lactate. The risk of lactic acidosis increases with renal or hepatic impairment, aged 65 years or older, having a radiological study with contrast, surgery, or other procedures, hypoxic states, and excessive alcohol intake. If lactic acidosis is suspected, metformin hydrochloride should be discontinued, supportive measures started in a hospital setting. Prompt hemodialysis is recommended.
Serious side effects of Riomet ER
Along with its needed effects, metformin (the active ingredient contained in Riomet ER) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking metformin:
- Abdominal or stomach discomfort
- cough or hoarseness
- decreased appetite
- fast or shallow breathing
- fever or chills
- general feeling of discomfort
- lower back or side pain
- muscle pain or cramping
- painful or difficult urination
- blurred vision
- chest discomfort
- cold sweats
- cool, pale skin
- difficult or labored breathing
- fast, irregular, pounding, or racing heartbeat or pulse
- feeling of warmth
- increased hunger
- increased sweating
- redness of the face, neck, arms, and occasionally, upper chest
- slurred speech
- tightness in the chest
- unusual tiredness or weakness
- Behavior change similar to being drunk
- difficulty with concentrating
- lack or loss of strength
- restless sleep
- unusual sleepiness
Other side effects of Riomet ER
Some side effects of metformin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.
Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Acid or sour stomach
- excess air or gas in the stomach or intestines
- full feeling
- loss of appetite
- metallic taste in the mouth
- passing of gas
- stomach upset or pain
- weight loss
- Abnormal stools
- bad, unusual, or unpleasant (after) taste
- change in taste
- difficulty with moving
- discoloration of the fingernails or toenails
- flu-like symptoms
- joint pain
- stuffy or runny nose
- swollen joints
For Healthcare Professionals
Applies to metformin: compounding powder, oral solution, oral suspension extended release, oral tablet, oral tablet extended release.
Gastrointestinal events such as nausea, vomiting, diarrhea, abdominal pain, and loss of appetite have been frequently reported during therapy initiation and resolve spontaneously in most cases.
Adverse events in the pediatric population appear to be similar in nature and severity to that published in adults.[Ref]
Common (1% to 10%): Hypoglycemia
Very rare (less than 0.01%): Lactic acidosis[Ref]
Common (1% to 10%): Asthenia, chills, flu syndrome, accidental injury[Ref]
Very rare (less than 0.01%): Liver function test abnormalities, hepatitis[Ref]
Common (1% to 10%): Chest discomfort, flushing, palpitation[Ref]
Common (1% to 10%): Rash, nail disorder, increased sweating
Frequency not reported: Reduction in thyrotropin (TSH) levels[Ref]
Very common (10% or more): Infection (20.5%)[Ref]
Common (1% to 10%): Myalgia[Ref]
Common (1% to 10%): Lightheadedness, taste disturbances[Ref]
Common (1% to 10%): Headache[Ref]
Frequently asked questions
- What is the safest diabetes medication?
- Does metformin cause hypoglycemia?
- Is Invokana the same as metformin?
- How long does glucophage/Metformin stay in your system?
- Can Diabetes go away?
- What are the ingredient drugs contained in Qternmet XR?
More about Riomet ER (metformin)
- Check interactions
- Latest FDA alerts (18)
- Dosage information
- During pregnancy
- En español
1. "Product Information. Glucophage (metformin)." Bristol-Myers Squibb (2001):
2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
3. Cerner Multum, Inc. "Australian Product Information." O 0
4. "Product Information. Fortamet (metformin)." Physicians Total Care (2014):
5. "Product Information. Glumetza (metformin)." Biovail Pharmaceuticals Canada (2014):
6. "Product Information. Riomet (metformin)." Ranbaxy Pharmaceuticals (2014):
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.