testosterone

Action and Spectrum

Testosterone plays a crucial role in development and maintenance of male reproductive tissues by promoting secondary sexual characteristics and maintaining bone density. It also regulates sexual function, mood, cognitive function, metabolism, and cardiovascular health. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Edema 

Acne 

Menstrual irregularities 

Virilization 

Breast soreness 

Priapism 

Frequency not defined 

Gynecomastia 

Anaphylaxis 

Cholestatic jaundice syndrome 

Neoplasm of liver 

Anaphylaxis 

Black Box Warning

Anaphylaxis  

Contraindication / Caution

Contraindication/Caution: 

Testosterone works in development and maintenance of male reproductive tissues, promoting secondary sexual characteristics, maintaining bone density, regulating mood, cognitive function, regulating metabolism, and promoting cardiovascular health. 

Pregnancy / Lactation

Pregnancy consideration:  

Category X 

Breastfeeding warnings:  

methyltestosterone is excreted in breastmilk; hence contraindicated 

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 

• Category B: No evidence of risk to the fetus is found in animal reproduction studies, and there are not enough studies on pregnant women. 

• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for a human product; Pregnant women must take care of the potential risks. 

• Category D: There is adequate data with sufficient evidence of human fetal risk from various platforms. However, despite potential dangers may be used only in emergencies for potential benefits. 

• Category X: Drugs listed in this category outweigh the risks over benefits. The drug is not for pregnant women. 

• Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology 

Testosterone is an endogenous steroid hormone classified as an androgen, commonly prescribed for hormone replacement therapy in men with hypogonadism. Beyond this, it has additional medical uses. Its pharmacological activity includes binding to androgen receptors, being converted into dihydrotestosterone (DHT) and estradiol, and influencing gene expression to produce its physiological effects. 

Pharmacodynamics: 

Testosterone binds to androgen receptors in various tissues causing hair growth, sebum production, and prostate size. It also promotes protein synthesis in skeletal muscle which increases red blood cell production and improves erythropoietic function. 

Pharmacokinetics: 

Absorption 

Peak plasma concentration is 852.4 ng/dL  

Distribution 

Circulating testosterone gets bound to albumin and (SHBG) sex hormone-binding globulin  

Protein bound for  Xyosted and Aveed is 40% (SHBG) and 2% (free) 

Depo-Testosterone and Testopel: 98% (SHBG); and 2 % (free) 

Metabolism 

testosterone undecanoate is metabolized to testosterone through the ester cleavage of undecanoate group 

testosterone enanthate is metabolized to testosterone through ester cleavage of an enanthate group 

testosterone is metabolized to the various 17-keto steroids  

Elimination and Excretion 

The half-life is 8 days (for Depo-Testosterone) and 10-100 minutes (for Testopel) 

The drug is excreted 90% in urine and 6% in feces  

Adminstartion

Testosterone can be given through injections, transdermal patches, topical gels, buccal patches, and oral capsules. The frequency and route depend on the patient age, medical history, and treatment condition. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: testosterone 

Pronounced: tes-TOS-ter-one 

Why do we use testosterone? 

Testosterone is a hormone responsible for male reproductive development and sexual characteristics. It is used in testosterone replacement therapy to treat hypogonadism, delayed puberty, menopause symptoms, HIV-associated wasting syndrome, osteoporosis, and breast cancer. It can also improve athletic performance, but its use is prohibited in competitive sports due to health risks.