Please consult your physician before taking any medication. Formulation and Dosage Form Each vial contains: 1,000 mg testosterone undecanoate (250 mg testosterone undecanoate / ml) Vehicle c.b.p. 4 ml. Dosage and administration NEBIDO ® (light bulb up to 1000 mg testosterone undecanoate) is injected every 10 to 14 weeks. Injections given this often help maintain sufficient levels of testosterone without causing buildup. The injections should be administered slowly. NEBIDO ® are strictly administered by intramuscular injection. Special attention should be paid to avoid intravascular injection. Start of treatment: serum testosterone levels should be measured before starting treatment. The first injection interval can be reduced to a minimum of 6 weeks. With this loading dose levels at steady state is reached quickly. Individualization of treatment: It is advisable to measure serum testosterone levels, occasionally, at the end of the interval between injections. Levels below the normal range serum levels indicate the need to shorten the interval between injections. In case of high serum levels shall be considered to extend the interval between injections. The interval between injections will remain within the recommended range of 10 to 14 weeks. INDICATIONS: Testosterone replacement in primary and secondary male hypogonadism. Pharmacokinetics: Pharmacodynamic Properties Pharmacotherapeutic group: Androgen-oxoandrosteno derivative 2. Testosterone undecanoate is an ester of the natural androgen testosterone. The active, testosterone, is formed by cleavage of the side chain. Testosterone is the more important androgen in men, and is mainly synthesized in the testes and, to a lesser extent in the adrenal cortex. Testosterone is responsible for the expression of male characters during fetal development, early childhood and puberty; subsequently maintaining the male phenotype and functions of androgen dependent (eg, spermatogenesis, accessory sex glands). It also acts, for example in skin, muscle, skeleton, kidney, liver, bone marrow and CNS. Insufficient secretion of testosterone produces male hypogonadism, characterized by low serum testosterone concentrations. Symptoms associated with male hypogonadism include, among others, impotence and decreased libido, fatigue and depressed mood, plus absence, incomplete development or regression of secondary sexual characteristics, increased risk of osteoporosis, increased visceral fat and loss of muscle mass and strength. Exogenous androgens are given to improve the deficient endogenous testosterone levels and symptoms related to these. Depending on the target organ, the spectrum of activities of testosterone is primarily androgen (eg, prostate, seminal vesicles, epididymis) or anabolic protein (muscle, bone, hematopoietic, kidney, liver). The effects of testosterone on organs arising after conversion peripheral estradiol, which binds to estrogen receptors in the nucleus of target cells, for example, pituitary, fat, brain, bone, and testicular Leydig cells. In hypogonadal men, androgens decrease body fat mass, increasing lean body mass, muscle strength and prevent bone loss. Androgens may improve sexual function and also have positive psychotropic effects to enhance the mood. Pharmacokinetics Absorption Nebido® a depot preparation testosterone undecanoate intramuscularly administered and, therefore, avoid first pass effect. After intramuscular injection of testosterone undecanoate in oil solution, the compound is released gradually from the depot and is almost entirely metabolized by esterases in the serum testosterone and undecanoic acid. Increased serum levels of testosterone above the baseline and can be measured one day after administration. Distribution: In two separate studies, overall mean concentrations of 24 and 45 nmol / L testosterone about 14 and 7 days, respectively, were determined following single administration im 1,000 mg of testosterone undecanoate to hypogonadal men. The posmáximos decreased testosterone levels estimated half-life of about 53 days. In the serum of men, approximately 98% of circulating testosterone is bound to SHBG and albumin. Only considered biologically active free fraction of testosterone. After intravenous infusion of testosterone to elderly men, apparent volume of distribution of approximately 1.0 L / kg was determined. Metabolism testosterone formed by cleavage of the ester is testosterone undecanoate metabolized and excreted in the same way as the endogenous testosterone. Undecanoic acid is metabolized by beta-oxidation in the same way that other aliphatic carboxylic acids. Elimination Testosterone undergoes extensive hepatic and extrahepatic metabolism. Following administration of radiolabeled testosterone, about 90% of the radioactivity appears in urine as glucuronic acid conjugates and sulfuric acid, and 6% in feces is detected after the enterohepatic circulation. Urinary androsterone and etiocholanolone products include. Steady-state conditions: After repeated im injection 1,000 mg of testosterone undecanoate to hypogonadal men using a 10-week interval between two injections, steady state conditions were reached between the third and the fifth administration. Mean Cmax and Cmin. testosterone at steady state were about 42 and 17 nmol / L, respectively. Testosterone levels in serum posmáximos decreased with a half life of about 90 days, which corresponds to the rate of release from the reservoir.
