Primoteston depot contains a derivative of the natural male sex hormone
testosterone, testosterone enanthate as its active ingredient.
After intramuscular administration, testosterone enanthate becomes
completely systemically available. The compound is gradually released from
the depot with a half-life of about 4.5 days and is cleaved into
testosterone and enanthic acid.
Maximum concentrations of testosterone of 20 ng/ml were measured 1.5 - 3
days after i.m. administration of 250 mg of testosterone enanthate to young
men. Thereafter, testosterone levels in the plasma decreased with a
half-life of about 4.5 days which corresponds to the release rate from
depot.
Testosterone concentrations of=2 ng/ml were maintained for 20 days and
concentrations=1 ng/ml for 26 days. With a dose of 250 mg testosterone
enanthate, patients receive a total dose of 180 mg testosterone. Around the
time where maximum serum levels are achieved, average daily doses after 1
and 2 weeks correspond to 12 and 4 mg testosterone, respectively. Within
approximately 4 weeks after drug administration, testosterone is completely
released from the depot.
Testosterone, which was generated by ester cleavage from testosterone
enanthate, is metabolised and excreted the same way as endogenous
testosterone. The enanthic acid is metabolised by ß-oxidation in the same
way as other aliphatic carboxylic acids. The metabolic clearance of
testosterone is calculated to be 16±7 ml/min/kg and refers to hepatic and
extra-hepatic metabolism of testosterone. The metabolites of testosterone
are eliminated with a half-life of 7.8 days. About 90 % are excreted renally
and about 10 % with the bile.
Testosterone is highly bound to serum proteins, in particular to albumin and
SHBG. The absolute bioavailability of testosterone from the ester was almost
complete, indicating a rapid and efficient cleavage of the ester.
Injection of 250 mg testosterone enanthate every 3 - 4 weeks will not result
in any clinically relevant accumulation of testosterone in serum.
Like all oily solutions, Primoteston depot must be injected intramuscularly.
Experience shows that the short-lasting reactions (urge to cough, coughing
fits, respiratory distress) which occur in rare cases during or immediately
after the injection of oily solutions can be avoided by injecting the
solution extremely slowly.
Disorders of potency based on an androgen deficiency are eliminated by
administration of Primoteston depot. Mental changes, stress and conflict
situations and physical ailments are frequently predominant in potency
disorders. Supportive therapy with androgens can be beneficial during the
elimination and treatment of causative factors and disorders.
For the therapy of diminishing androgen production - frequently with onset
in middle age - and its possible concomitant symptoms, e.g. reduced
performance, rapid fatigability, diminishing memory and ability to
concentrate, disorders of libido and potency, depressive moods,
irritability, sleep disturbances, general vegetative complaints.
The solvent of Primoteston depot has been used for many years in numerous
formulations for human use. In this time no local irritant effects have been
observed which could object to its further use. Many years of clinical
experience have shown only sporadic cases in which allergenic reactions have
been suspected. No clear sensitising effect has been proven.
On the whole, the available toxicological findings do not present any
objections to the prescriptive use of Primoteston depot in humans for the
given indications and at the dosages prescribed.
Adverse Effects
High-dosed or long -term administration of testosterone occasionally
increases the tendency to water retention and oedema. Caution should
therefore be exercised in patients predisposed to oedema.
In very rare cases jaundice and liver function test abnormalities were
reported. Rare cases of polycythemia were reported. Gynaecomastia may occur
in rare cases. Acne may occur.
Depending on the individual sensitivity to androgenic impulses, women may
develop signs of virilisation, e.g. acne, hirsutism, voice changes
(particular care is necessary in women whose occupations involve singing or
speaking).
Interactions
Phenobarbital increases the break down of steroid hormones in the liver
(possible impairment of efficacy).
The clotting status should be monitored particularly closely when
Primoteston depot is administered together with coumarin derivatives.
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