Data Sheet

PANTESTON

testosterone undecanoate 40mg capsule

Presentation

40mg capsules: glossy, oval, soft gelatin capsule, reddish-brown in colour, coded DV/3 and ORG in white, and containing 40mg testosterone undecanoate. Dimensions about 11mm in length and about 8mm in diameter.

Uses

Actions

Testosterone is the principal endogenous hormone essential for normal growth and development of the male sex organs and male secondary sex characteristics. During adult life testosterone is essential for the functioning of the testes and accessory structures, and for the maintenance of libido, sense of well-being, erectile potency, prostate and seminal vesicle function.

Treatment of hypogonadal males with PANTESTON results in a clinically significant rise of plasma concentrations of testosterone, dihydrotestosterone and androstenedione, as well as a decrease of SHBG (sex hormone binding globulin). In males with primary (hypergonadotropic) hypogonadism treatment with PANTESTON results in a normalization of pituitary function.

Pharmacokinetics

Following oral administration, part of the testosterone undecanoate is co-absorbed with the oleic acid from the intestine into the lymphatic system, thus circumventing the first-pass inactivation by the liver. During absorption testosterone undecanoate is partly reduced to dihydrotestosterone undecanoate. From the lymphatic system it is released into the plasma. In plasma and tissues both testosterone undecanoate and dihydrotestosterone undecanoate are hydrolysed to yield the natural male androgens testosterone and dihydrotestosterone. Single administration of 80-160mg PANTESTON leads to a clinically significant increase of total plasma testosterone with peak-levels of approximately 40 nmol/l (C_max) reached approximately 4-5 hours after administration (t_max). Plasma testosterone levels remain elevated for at least 8 hours. Testosterone and dihydrotestosterone are metabolised via the normal pathways. Excretion mainly takes place via the urine as conjugates of etiocholanolone and androsterone.

Indications

In the male

Testosterone replacement therapy for primary or secondary hypogonadal disorders, for example:

• after castration
• eunuchoidism
• hypopituitarism
• endocrine impotence
• male climacteric symptoms such as decreased libido and decreased mental and physical activity
• certain types of infertility due to disorders of spermatogenesis.

Moreover, testosterone therapy may be indicated in osteoporosis in the male due to androgen deficiency.

Dosage And Administration

Dosage

In general, dosage should be adjusted according to the response of the individual patient. Usually, an initial dosage of 120-160mg daily for 2-3 weeks is adequate, followed by a maintenance dosage of 40-120mg daily.

Administration

PANTESTON capsules should be taken after meals, with a little fluid if necessary, and swallowed whole without chewing. It is preferable that half of the daily dose be taken in the morning and the other half in the evening. If an uneven number of capsules is to be taken, the larger dose should be taken in the morning.

Contraindications

Known or suspected prostatic or mammary carcinoma.

Warnings And Precautions

• If androgen-associated adverse reactions occur, PANTESTON treatment should be interrupted and, after disappearance of the symptoms, be resumed at a lower dosage.
• Patients with latent or overt cardiac failure, renal dysfunction, hypertension, epilepsy or migraine (or a history of these conditions) should be monitored, since aggravation or recurrence may occasionally be induced.
• Androgens should be used cautiously in prepubertal boys to avoid premature epiphyseal closure or precocious sexual development. Skeletal maturation should be monitored regularly.
• The use of steroids may influence the results of certain laboratory tests.
• Hepatotoxicity has been reported after prolonged use of some testosterone derivatives, particularly 17-alpha alkyl derivatives. Hepatotoxicity has so far not been reported with PANTESTON, but the possibility of it should not be entirely excluded.
• Use should be restricted in cases of male hypogonadism to those in which testosterone levels have been demonstrated to be low.
• In the treatment of males, stimulation to the point of increasing nervous, mental and physical activities beyond the patient's cardiovascular capacity should be avoided.

Adverse Effects

The following adverse reactions have been associated with androgen therapy:

• Priapism and other signs of excessive sexual stimulation.
• In prepubertal boys, precocious sexual development, an increased frequency of erections, phallic enlargement and premature epiphyseal closure.
• Oligospermia and decreased ejaculatory volume.
• Water and salt retention.

Interactions

Enzyme-inducing agents may exert different effects on the endogenous and exogenous testosterone levels. Therefore adjustment of dose for PANTESTON may be required.

Overdosage

The acute oral toxicity of testosterone undecanoate is very low. High dosages of PANTESTON may cause diarrhoea due to the solvent oleic acid contained in the capsules. Treatment may consist of emptying the stomach and supportive measures.

Pharmaceutical Precautions

For wholesale and pharmacy: Store 36 months at 2-8°C.

For the user: Store in a dry place at room temperature. Use within 90 days.

Medicine Classification

Prescription Medicine.

Package Quantities

HDPE bottles containing 60 capsules.

Further Information

Nil.

Name and Address

Schering-Plough
a division of Schering-Plough Animal Health Ltd
36 Kitchener St
Auckland
Telephone: (09) 375 9210

Date of Preparation

7 October 2008

Version 1