Testosterone, main natural androgen, is responsible for the development and maintenance of male secondary sex characteristis, exerting a significant anabolic action.
The latter contributes, especially, to accelerate the growth process at puberty, by stimulation of bone growth and modulation of the welding process of the epiphysis of long bones. In normal subjects it promotes the activity of the enzime RNA polymerase and the synthesis of specific RNA, resulting in increased protein production.
Testosterone stimulates erythrocite production because it promotes the synthesis of erythropoiesis stimulating factors.
Congenital or acquired primary hypogonadism: in cases of testicular failure due to cryptorchidism, bilateral torsion, testicular absence syndrome or orchydoctomy.
Hypogonadotrophic hypogonadism: in cases of congenital or acquired deficiency of LH-RH (luteinising hormone liberating hormone) or hypothalamic pituitary damage due to surgeries, traumas, tumors or radiation.
Delayed Puberty: in cases of history of delayed puberty, not secondary to a pathological disorder, in patients who did not respond to psychological support therapy.
Male Menopause: as replacement therapy in impotence or other symptoms associated to this disorder, when the etiology is due to a confirmed androgen deficiency.
Specific anemia: aplastic anemia myelofibrosis, myelosclerosis, chronic idiopathic myelofibrosis, hypoplastic anemias caused by malignancies or myelotoxic drugs.
Inoperable breast carcinoma: as palliative secondary – tertiary treatment of metastatic breast cancer in women with hormone-responsive tumors or women that have demonstrated prior response to hormonal therapy.
The following reactions require medical supervision:
Virilization and menstrual irregularities in women, irritability of the bladder, gynecomastia. Anaphylaxis, oedema, erythrocytes, gastrointestinal irritation, hypercalcemia and polycythemia, androgenic alopecia, seborrhea and acne in women and men. Carcinoma, prostatic hypertrophy and increased sexual desire.
Adverse reactions of rare ocurrence during a long term therapy or with high doses are: hepatic necrosis, leucopenia, liver purpura.
Other adverse reactions are: constipation, nausea, diarrhea, infection, redness, pain or discomfort at injection site, changes in libido, stomachache, sleeping disorders, impotence, testicular atrophy, headache, anxiety, depression, generalized paresthesia, sleep apnea, rash.
This drug is contraindicated in male subjects with breast cancer, diagnosed or suspected prostate cancer or adenoma, severe heart, liver or kidney failure, in prepubertal individuals or in aggressive state, during pregnancy, hypercalcemia.
Hypogonadism, climaterium or impotence (male replacement therapy) 50 to 400 mg I.M. every 2-4 weeks.
Delayed male puberty (replacement therapy) 25 to 200 mg every 2-4 weeks, for a limited period of 6 months.
Antineoplastic, in inoperable breast cancer (women) 200 to 400 mg I.M. every 2 to 4 weeks.
PRECAUTIONS AND WARNINGS
In palliative treatment of breast cancer do not continue therapy if after three months of treatment ailment continues to develop or hypocalcemia has been reported at any phase of treatment.
Androgen therapy in women, even for a short term, can cause virilization, especially of vocal cords and body hair.
Androgen therapy is not recommended to enhance athletic performance. In children, this drug must be used carefully due to adverse effects on bone growth that can be accelerated without producing a compensatory gain in lineal growth.
When male subjects over 50 are treated with androgens, there is a bigger risk of prostate enlargement or development of prostate cancer. For this reason, prostate examinations and blood counts must be indicated before prescribing androgens to males within this age range.
During long-term treatment oligospermia, azoospermia or reduced sperm function can occur, resulting in possible infertility, with spontaneuos remission after withdrawal of treatment.
Patients with benign prostatic hypertrophy can develop acute urethral obstruction. In this case drugs should be immediately withdrawn.
Calcium leves in serum and urine should be frequently measured in women with metastatic breast carcinoma under testosterone treatment.
During treatment of prepubertal subjects bone x-rays should be performed every six months.
In patients with acute intermittent porphyria, androgens can precipitate seizures of this condition.
It is usually recommended to start with full doses and titrate according to individual needs.
Testosterone can interact with the following drugs:
– Adrenocorticosteroids, glycocorticosteroids or mineralocorticosteroids: corticotrophin, food or drugs that contain sodium (may increase risk of oedema and predispose to acne).
– Oral antidiabetic agents or insulin (because there might be a decrease of glucose serum leves).
– Hepatotoxic drugs (increase of hepatotoxicity).
Frequent doses can trigger symptoms of slow remission, because it is a long-acting medication. Immediate discontinuation of the medication is recommended.
Use of wet needle or syringe can cause claudiness of solution that does not affect the effectiveness of the drug. If crystalls are formed in vials, gentle heating by friction between the hands or shaking can dissolve crystals.
Intramuscular injection is to be administered deep into the muscle, gluteus or deltoid muscle. Do not administer intravenously.
Keep at 15-30º C. Do not freeze. Shake well before use.