Medical Editor: John P. Cunha, DO, FACOEP
Riomet ER (metformin hydrochloride for extended-release oral suspension) is a biguanide indicated as an adjunct to diet and exercise to improve glycemic control in adults and pediatric patients 10 years of age and older with type 2 diabetes mellitus. Common side effects of Riomet ER include:
- diarrhea,
- nausea,
- vomiting,
- gas (flatulence),
- weakness/lethargy,
- indigestion,
- abdominal discomfort, and
- headache
The adult starting dose of Riomet ER is 500 mg (5 mL) orally once daily, with the evening meal. Increase the dose of Riomet ER in increments of 500 mg (5 mL) weekly, up to a maximum dose of 2,000 mg (20 mL) once daily, with the evening meal. Riomet ER may interact with alcohol, carbonic anhydrase inhibitors, ranolazine, vandetanib, dolutegravir, cimetidine, insulin secretagogues or insulin, diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, and isoniazid. Tell your doctor all medications and supplements you use. Tell your doctor if you are pregnant or plan to become pregnant before using Riomet ER; it is unknown how it would affect a fetus. There are risks to the mother and fetus associated with poorly controlled diabetes mellitus in pregnancy. Riomet ER passes into breast milk but its effects on nursing infants are unknown. Consult your doctor before breastfeeding.
Our Riomet ER (metformin hydrochloride for extended-release oral suspension) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
SLIDESHOW
Type 2 Diabetes: Signs, Symptoms, Treatments See SlideshowGet emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Some people using metformin develop lactic acidosis, which can be fatal. Get emergency medical help if you have even mild symptoms such as:
- unusual muscle pain;
- feeling cold;
- trouble breathing;
- feeling dizzy, light-headed, tired, or very weak;
- stomach pain, vomiting; or
- slow or irregular heart rate.
Common side effects may include:
- low blood sugar;
- nausea, upset stomach; or
- diarrhea.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Read the entire detailed patient monograph for Riomet ER (Metformin Hydrochloride for Extended-release Oral Suspension)
QUESTION
______________ is another term for type 2 diabetes. See AnswerSIDE EFFECTS
The following adverse reactions are also discussed elsewhere in the labeling:
- Lactic Acidosis [see BOXED WARNING and WARNINGS AND PRECAUTIONS]
- Vitamin B12 Deficiency [see WARNINGS AND PRECAUTIONS]
- Hypoglycemia [see WARNINGS AND PRECAUTIONS]
Clinical Studies Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Metformin Immediate-Release
In a U.S. clinical trial of metformin immediate-release tablet in patients with type 2 diabetes mellitus, a total of 141 patients received metformin immediate-release tablet up to 2,550 mg per day. Adverse reactions reported in greater than 5% of metformin immediate-release tablet treated patients and that were more common than in placebo-treated patients, are listed in Table 1.
Table 1: Adverse Reactions from a Clinical Trial of
Metformin Occurring >5% and More Common than Placebo in Patients with Type 2
Diabetes Mellitus
| Metformin Immediate-Release Tablet (n = 141) |
Placebo (n = 145) |
|
| Diarrhea | 53% | 12% |
| Nausea/Vomiting | 26% | 8% |
| Flatulence | 12% | 6% |
| Asthenia | 9% | 6% |
| Indigestion | 7% | 4% |
| Abdominal Discomfort | 6% | 5% |
| Headache | 6% | 5% |
Diarrhea led to discontinuation of metformin immediate-release tablet in 6% of patients. Additionally, the following adverse reactions were reported in ≥ 1% to ≤ 5% of metformin immediaterelease tablet treated patients and were more commonly reported with metformin immediate-release tablet than placebo: abnormal stools, hypoglycemia, myalgia, lightheaded, dyspnea, nail disorder, rash, sweating increased, taste disorder, chest discomfort, chills, flu syndrome, flushing, palpitation.
In metformin immediate-release tablet clinical trials of 29 week duration, a decrease to subnormal levels of previously normal serum vitamin B12 levels was observed in approximately 7% of patients.
Pediatric Patients
In clinical trials with metformin in pediatric patients with type 2 diabetes mellitus, the profile of adverse reactions was similar to that observed in adults.
Metformin Extended-Release
In placebo-controlled trials, 781 patients were administered metformin extended-release tablet. Adverse reactions reported in greater than 5% of the metformin extended-release tablet patients, and that were more common in metformin extended-release tablet- than placebo-treated patients, are listed in Table 2.
Table 2: Adverse Reactions from Clinical Trials of
Metformin Hydrochloride Extended- Release Tablet Occurring >5% and More
Common than Placebo in Patients with Type 2 Diabetes Mellitus
| Adverse Reaction | Metformin Hydrochloride Extended- Release Tablet (n = 781) |
Placebo (n = 195) |
| Diarrhea | 10% | 3% |
| Nausea/Vomiting | 7% | 2% |
| *Reactions that were more common in metformin hydrochloride extended-release tablet- than placebo-treated patients. | ||
Diarrhea led to discontinuation of metformin hydrochloride extended-release tablet in 0.6% of patients. Additionally, the following adverse reactions were reported in ≥ 1.0% to ≤ 5.0% of metformin hydrochloride extended-release tablet patients and were more commonly reported with metformin hydrochloride extended-release tablet than placebo: abdominal pain, constipation, distention abdomen, dyspepsia/heartburn, flatulence, dizziness, headache, upper respiratory infection, taste disturbance.
Postmarketing Experience
The following adverse reactions have been identified during post approval use of metformin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Cholestatic, hepatocellular, and mixed hepatocellular liver injury have been reported with postmarketing use of metformin.
Read the entire FDA prescribing information for Riomet ER (Metformin Hydrochloride for Extended-release Oral Suspension)
© Riomet ER Patient Information is supplied by Cerner Multum, Inc. and Riomet ER Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.