RiteMED Metformin HCl Adverse Reactions

Metformin may provoke or augment lactic acidosis particularly if it is present in high concentrations in the blood. Some of the symptoms of lactic acidosis may mimic certain adverse effects of metformin. Physicians should instruct their patients to recognize the onset of symptoms of lactic acidosis to avoid this adverse reaction.
The most frequent adverse effects reported with metformin include nausea, vomiting, diarrhea, abdominal pain and loss of appetite. These adverse effects occur during initiation of treatment and resolve spontaneously in most cases.
Blood and lymphatic system disorders: Decrease in serum vitamin B₁₂, megaloblastic anemia (rare); serum folic acid concentrations do not appear to decrease substantially in patients receiving metformin.
Metabolism and nutrition disorders: Hyperglycemia, hypoglycemia (may occur when metformin is given concomitantly with sulfonylureas and/or alcohol), lactic acidosis, weight decreased.
Nervous system disorders: Agitation, dizziness, headache, lightheadedness.
Cardiac disorders: Chest discomfort, palpitations.
Vascular disorders: Flushing, hypertension.
Respiratory, thoracic and mediastinal disorders: Dyspnea, flu syndrome, pneumonitis with vasculitis, rhinitis, upper respiratory infection.
Gastrointestinal disorders: Abdominal discomfort (e.g., bloating, abdominal cramps), abdominal distention, abnormal stools/loose stools, anorexia, constipation, dry mouth, dyspepsia/heartburn, epigastric discomfort, flatulence, gastric disorder, gastric ulcer, gastrointestinal disorder, indigestion, taste disturbance specifically metallic taste in the mouth.
Hepatobiliary disorders: Abnormal liver function tests, autoimmune hepatitis, cholestasis, hepatic injury, hepatitis.
Skin and subcutaneous tissue disorders: Erythema, nail disorder, pruritus, rash, skin lesion, urticaria.
Musculoskeletal and connective tissue disorders: Asthenia, chills, musculoskeletal pain, myalgia.
Renal and urinary disorders: Urinary tract infection.
General disorders and administration site conditions: Fatigue, increased sweating.