Pharmacotherapy of Klinefelter syndrome is an adjuvant treatment, which is mainly using hormonal replacement, to help improve patient’s life. 

An excellent treatment of Klinefelter syndrome (KS) is the testosterone replacement therapy (TRT) that consists in the fact of giving testosterone (the primary male sex hormone) through injections to the male at the age he is starting puberty. Replacement therapy with long acting testosterone depends on the age of patient, and may be commenced at 11-12 years of age. 

Generally, sex hormone levels and bone mineral density (BMD), which is controled by the testosterone levels, are lower in patients with KS than normal. Androgens (primary male hormones) play an important role in the prenatal and pubertal virilization of the external genitalia in 46,XY fetuses. The effect of androgens plays a critical role in male sexual differentiation, development and maintenance of secondary male characteristics (Pic. 1) and the induction and maintenance of spermatogenesis (development of sperms from germ cells).

TRT results in the that the male develops normally, meaning his voice gets deep, his penis grows, he gets hair and also increasing muscles mass as well as reduced breast tissue growth. 

Testosterone replacement therapy can not improve fertility or testicle enlargement, but is has possitive impact on bone density which leads to reduction of risk of fractures. Testosterone therapy can also help in improving concentration, mood and self esteem.

Hormonal therapy has possitive impact on any man which can and is taking this medication. 

TRT cannot be prescribed for those men, which have any of the conditions mentioned below, because any of this health conditions which can be worsened by the TRT.

These conditions include:

  • benigh prostatic hypertophy - the prostate growth is stimulated by the testosterone, THT can enlarged the gland which leads to difficulties with urination
  • prostate cancer - testosterone can stimulate prostate cancer to grow, it is recommended to check the prostate before the onsed of TRT
  • sleep apnea - TRT can worsened this condition
  • blood clots - TRT is asociated with increased risk of deep vein thrombosis (the formation of a blood clot within a deep vein) and pulmonary embolism
  • congestive heart failure - for men with severe congestive heart failure the TRT is forbidden

Hormonal replacement can have side effects, which can be relatively minor, but some of them can be very serious. Minor side effects include acne, fluid retention or increased urination. Severe potential side effects include breast enlargement, decreased testicle size and decreased sperm count. Increased cholesterol levels can lead to atherosclerosis (narrowing of blood vessels) which is a risk factor of heart attack or stroke. Testosterone therapy can lowered the amount of red blood cells which is accompanied by muscle pain, high blood pressure, blurry vision, chest pain and there is higher possibility of blood clots.

If a testosterone treatment is started early in puberty, the child may develop more normally than they would without it. The infertility is not improved with TRT.

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Klinefelters Syndrome ―sourced from Wikispaces licensed under CC BY- SA 3.0
Klinefelter's Syndrome in an Adolescent ―by Uchenna and Ifeanyichukwu licensed under CC BY- SA 4.0
Klinefelter syndrome ―sourced from Wikivisually licensed under CC BY- SA 3.0
Klinefelter Syndrome ―sourced from Wikispaces licensed under CC BY- SA 3.0
Klinefelter's syndrome.jpg ―by Unknown licensed under CC BY- SA 3.0
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