Pharmacology of testosterone preparations

As all other androgens, testosterone derives from the basic structure of androstane. This molecule consists of three cyclohexane and one cyclopentane ring (perhydro-cyclopentanephenanthrene ring) and a methyl group each in position 10 and 13. Androstane itself is biologically inactive and gains activity through oxygroups in position 3 and 17. Testosterone, the quantitatively most important androgen synthesized in the organism, is characterized by an oxy group in position 3, a hydroxy group in position 17 and a double bond in position 4 (Fig. 14.1).

Table 14.1 Mode of application and dosage of various testosterone preparations

Preparation

Route of application

Full substitution dose

In clinical use

Testosterone undecanoate

oral

2-4 capsules a 40 mg per day

Testosterone tablets

buccal

30 mg / twice daily

Testosterone enanthate

intramuscular injection

200-250 mg every 2-3 weeks

Testosterone cypionate

intramuscular injection

200 mg every 2 weeks

Testosterone undecanoate

intramuscular injection

1000 mg every 10-12 weeks

Testosterone implants

implantation under the

4 implants a 200 mg every

abdominal skin

5-6 months

Transdermal testosterone patch

scrotal skin

1 patch per day

Transdermal testosterone patch

non-scrotal skin

1 or 2 systems per day

Transdermal testosterone gel

non-scrotal skin

5 to 10 g gel per day

Under development

Testosterone cyclodextrin

sublingual

not yet determined

Testosterone buciclate

intramuscular injection

not yet determined

Testosterone microcapsules

subcutaneous injection

not yet determined

Obsolete

17a-Methyltestosterone

oral

Fluoxymesterone

sublingual/oral

To make testosterone therapeutically effective three approaches have been used:

1) different routes of administration,

2) esterification in position 17, and

3) chemical modification of the molecule.

In addition, these approaches have been combined. Since of practical clinical relevance, the route of administration is used here for categorizing the various testosterone preparations (overview in Table 14.1).

Hair Loss Prevention

Hair Loss Prevention

The best start to preventing hair loss is understanding the basics of hair what it is, how it grows, what system malfunctions can cause it to stop growing. And this ebook will cover the bases for you. Note that the contents here are not presented from a medical practitioner, and that any and all dietary and medical planning should be made under the guidance of your own medical and health practitioners. This content only presents overviews of hair loss prevention research for educational purposes and does not replace medical advice from a professional physician.

Get My Free Ebook


Post a comment