From the central nervous system (CNS): headache, fatigue, with prolonged use of large doses (more than 1000 mg) - increased excitability of the central nervous system, sleep disturbance.
From the digestive system: irritation of the mucosa of the gastrointestinal tract, with prolonged use of large doses - nausea, vomiting, diarrhea, hyperacid gastritis, ulceration of the mucous membrane of the gastrointestinal tract.
From the endocrine system: oppression of insular function pancreas (hyperglycemia, glucosuria).
From the urinary system: moderate pollakiuria (when taking a dose of more than 600 mg / day), with long-term use of large doses - hyperoxaluria,formation of urinary stones from calcium oxalate, damage to the glomerular apparatus of the kidneys.
From the side of the cardiovascular system: with prolonged use of large doses - a decrease in the permeability of capillaries (possibly worsening of tissue trophism, increased blood pressure, hypercoagulation, development of microangiopathies).
Allergic reactions: skin rash, anaphylactic shock.
Laboratory indicators: thrombocytosis, hyperprothrombinemia, erythropenia, neutrophilic leukocytosis, hypokalemia, glucosuria.
Other: hypervitaminosis, a feeling of heat, with prolonged use of large doses - the retention of sodium and liquid, the disruption of the exchange of zinc, copper.
If any side effects occur, stop taking the medication and consult a doctor.