From the nervous system: drowsiness, dizziness, insomnia (at the beginning of treatment), with prolonged use in high doses (0.5-1.5 g / day) - akathisia, dystonic extrapyramidal reactions (spasms of the muscles of the face, neck and back, tick-like movements or twitches, the movement of the trunk, the inability to move the eyes, weakness in the arms and legs), parkinsonism (difficulty in speaking and swallowing, loss of balance control, masklike face, shuffling gait, stiffness of hands and feet, trembling of hands and fingers), tardive dyskinesia (smacked and wrinkled lips, cheeks inflating, rapid or vermiform movements of the tongue, uncontrolled chewing movements, uncontrolled movements of hands and feet),malignant neuroleptic syndrome (convulsions, difficulty or rapid breathing, palpitations or irregular heartbeats, hyperthermia, unstable blood pressure, increased sweating, loss of control of urination, severe muscle stiffness, unusually pale skin, excessive fatigue and weakness), psychic indifference, late reactions to external stimuli and other changes in the psyche, convulsions.
From the genitourinary system: retention of urine, decreased potency, frigidity (at the beginning of treatment), decreased libido, ejaculatory disorders, priapism, oliguria.
From the endocrine system: hypo- or hyperglycemia, hyperprolactinaemia, galactorrhea, swelling or pain in the mammary glands, gynecomastia, amenorrhea, dysmenorrhea, weight gain.
From the digestive system: loss of appetite, dry mouth, constipation (at the beginning of treatment), bulimia or anorexia, nausea, vomiting, diarrhea, gastralgia, cholestatic jaundice, hepatitis, intestinal paresis.
From the sense organs: visual impairment - paresis of accommodation (at the beginning of treatment), retinopathy, clouding of the lens and cornea, blurred vision. From the hematopoiesis: oppression of bone marrow hematopoiesis (thrombocytopenia, leukopenia, agranulocytosis (for 4-10 weeks of treatment), pancytopenia, eosinophilia), hemolytic anemia.
Laboratory indicators: false positive tests for pregnancy and phenylketonuria.
From the cardiovascular system: tachycardia, lowering of blood pressure (including orthostatic hypotension) especially in elderly patients and people with alcoholism (at the beginning of treatment), heart rhythm disturbances, lengthening of the interval Q-T, a decrease or inversion of the T wave, an increase in angina attacks (against the background of increased physical activity).
Allergic reactions: skin rash, hives, exfoliative dermatitis, angioedema.
Other: coloring of the skin from blue-violet to brown, photosensitization, discoloration of the sclera and cornea, a decrease in the tolerance of exposure to high temperatures (up to the development of heat stroke - hot dry skin, loss of sweating, confusion), myasthenia gravis.