According to the World Health Organization (WHO), unwanted the effects are classified according to the frequency of their development as follows: very often (> 1/10), often (> 1/100 to <1/10), infrequently (> 1/1000 to <1/100), rarely ( from> 1/10000 to <1/1000), very rarely (<1/10000); frequency is unknown - according to available data, it was not possible to establish the frequency of occurrence.
Application of the drug in monotherapy
The most common undesirable phenomena
(gynecomastia and / or pain in the thoracic region glands, sometimes
accompanied by galactorrhea) disappear when discontinuation or after a reduction in the dose of the drug.
Infectious and parasitic diseases
rarely: herpes zoster.
Benign, malignant and unspecified neoplasms (including cysts and polyps)
rarely: malignant neoplasm of mammary glands in men.
Violations of the blood and lymphatic system
rarely: lymphogenous edema.
Immune system disorders
rarely: lupus-like syndrome.
Disorders from the metabolism and nutrition
often: increased appetite;
rarely: lack of appetite (anorexia).
Disorders of the psyche
often: insomnia;
rarely: anxiety, depression.
Disturbances from the nervous system
rarely: dizziness, headache.
Disturbances on the part of the organ of sight
rarely: blurred vision.
Heart Disease
frequency unknown: QT interval elongation.
Vascular disorders
rarely: "flushes" of blood to the face (sensation of heat).
Disorders from the gastrointestinal tract
often: diarrhea, nausea, vomiting;
rarely: nonspecific symptoms from the gastrointestinal tract, heartburn, constipation.
Disturbances from the liver and bile ducts
often: hepatitis.
Disturbances from the skin and subcutaneous tissues
rarely: skin itch, ecchymosis (bleeding in the skin or mucous membranes);
very rarely: photosensitization reactions;
frequency unknown: changes in hair.
Violations of the genitals and mammary gland
very often: gynecomastia and / or pain in the mammary gland, galactorrhea;
rarely: decreased libido, reduced production of seminal fluid; frequency is unknown: an increase in the concentration of testosterone in the blood plasma (in the initial period of therapy).
General disorders and disorders at the site of administration
often: feeling tired;
rarely: swelling, general weakness, malaise, thirst, chest pain.
Impact on the results of laboratory and instrumental studies
often: transient violations of the liver.
Cases of development of malignant neoplasms of the mammary gland in men receiving flutamide therapy have been reported. In one case, the development of malignant neoplasm was noted against the background of pre-existing nodular formation in the mammary gland, revealed 3-4 months before the start of flutamide therapy in a patient with benign prostatic hypertrophy. After the removal and histological examination, a low-differentiated ductal adenocarcinoma was identified. Another report describes the development of gynecomastia two months after the initiation of flutamide therapy and the development of neoplasm - after 6 months in a patient receiving metastatic prostate cancer therapy. After 9 months from the start of therapy, the formation was removed, with histological the study revealed a low-grade ductal adenocarcinoma, T4N0M0 G3.
The use in combination with analogues of the hormone-releasing hormone (GnRH)
The most common side effects that develop against a background of combined therapy with flutamide and agonists of GnRH are "hot flashes", decreased libido, impotence, diarrhea, nausea and vomiting. With the exception of diarrhea, all these effects occur with a similar frequency with monotherapy with HGH agonists.
The incidence of gynecomastia compared with monotherapy with flutamide is significantly reduced when combined therapy is used. In clinical studies, there was no significant difference between the incidence of this undesirable effect with the use of hormone agonists in combination with flutamide and placebo. Violations of the blood and lymphatic system
rarely: anemia, leukopenia, thrombocytopenia;
very rarely: hemolytic anemia, macrocytic anemia, methemoglobinemia, sulfogemoglobinemia.
Disorders from the metabolism and nutrition
rarely: lack of appetite (anorexia);
highly rarely: hyperglycemia, aggravation of the severity of the course of diabetes mellitus.
Disorders of the psyche
rarely: anxiety, depression.
Disturbances from the nervous system
rarely: confusion, nervousness, numbness.
Heart Disease
frequency is unknown: extension of the QT interval.
Vascular disorders
very often: "tides" of blood to the face (sensation of heat);
rarely: hypertension;
frequency unknown: thromboembolism.
Disturbances from the respiratory system, chest and mediastinal organs
very rarely: symptoms from the respiratory system, including shortness of breath, interstitial lung disease.
Disorders from the gastrointestinal tract
often: diarrhea, nausea, vomiting;
rarely: nonspecific symptoms from the gastrointestinal tract.
Disturbances from the liver and bile ducts
infrequently: hepatitis;
rarely: liver failure, jaundice;
rarely: Cholestatic jaundice, hepatic encephalopathy, necrosis of hepatocytes. fatal outcome, as manifestations of severe hepatic insufficiency on background of hepatotoxic action
preparation.
Disturbances from the skin and subcutaneous tissues
rarely: skin rash;
highly rarely: photosensitivity reaction, erythema, ulceration of the skin, epidermal necrolysis.
Disturbances from the musculoskeletal and connective tissue are rare: symptoms of impairmentneuromuscular conductivity
(numbness, paresthesia, myalgia and / or myasthenia gravis in the hands, hands, feet, legs).
Disorders from the kidneys and urinary tract
rarely: pollakiuria, nocturia, incontinence;
very rarely: change of color of urine to amber or greenish-yellow color.
Violations of the genitals and mammary gland
Often: decreased libido, impotence;
infrequently: gynecomastia;
rarely: dyspareunia.
General disorders and disorders at the site of administration
rarely: swelling, irritation at the injection site.
Impact on results of laboratory and instrumental studies
rarely: increase in the concentration of urea and / or creatinine in the blood plasma.
Also, during the post-test trials of flutamide, adverse effects such as acute renal failure, interstitial nephritis, myocardial ischemia, micro-nodular changes in the mammary gland tissue were reported. To date, it is not possible to estimate the incidence of these unwanted effects.