Commonly reported side effects of metformin include: lactic acidosis, diarrhea, nausea, nausea and vomiting, vomiting, and flatulence. Other side effects include: asthenia, and decreased vitamin b12 serum concentrate. See below for a comprehensive list of adverse effects.
Applies to metformin: oral solution, oral tablet, oral tablet extended release
Oral route (Tablet; Tablet, Extended Release; Solution)
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.
Along with its needed effects, metformin 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:
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:
Applies to metformin: compounding powder, oral solution, 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.
Common (1% to 10%): Hypoglycemia
Very rare (less than 0.01%): Lactic acidosis
Very common (10% or more): Diarrhea (53.2%), nausea/vomiting (25.5%), flatulence (12.1%)
Common (1% to 10%): Indigestion, abdominal discomfort, abnormal stools, dyspepsia, loss of appetite
Very rare (less than 0.01%): Subnormal vitamin B12 levels
Common (1% to 10%): Asthenia, chills, flu syndrome, accidental injury
Very rare (less than 0.01%): Liver function test abnormalities, hepatitis
Common (1% to 10%): Chest discomfort, flushing, palpitation
Common (1% to 10%): Rash, nail disorder, increased sweating
Very rare (less than 0.01%): Erythema, pruritus, urticaria
Frequency not reported: Reduction in thyrotropin (TSH) levels
Very common (10% or more): Infection (20.5%)
Common (1% to 10%): Myalgia
Common (1% to 10%): Lightheadedness, taste disturbances
Common (1% to 10%): Headache
Common (1% to 10%): Rhinitis
Medically reviewed by USARx EDITORIAL TEAM Last updated on 1/1/2020.
Source: Drugs.com Metformin Hcl (www.drugs.com/metformin.html).