Testosterone enantate

How it works

It is slowly hydrolysed after injection to release testosterone, which acts on androgen receptors to maintain male secondary sexual characteristics, libido, muscle mass, bone density, and spermatogenesis.

Prescribing in practice

• It is contraindicated in known or suspected prostate or breast carcinoma in men, so prostate assessment and PSA (where appropriate) should be undertaken before and during treatment, as androgens can promote existing prostate cancer.
• Polycythaemia is a recognised effect, so haematocrit should be monitored periodically.
• It is contraindicated in pregnancy owing to the risk of virilising a female foetus, and is administered by deep intramuscular injection.

Monitoring

Monitor serum testosterone to optimise the dosing interval, alongside haematocrit, prostate status, PSA, lipids, and liver function during long-term use.

Counselling the patient

• This medicine is given as a deep injection into a muscle.
• Report trouble passing urine, breast swelling or tenderness, or unusual mood changes.
• Tell your clinician if you are planning to father a child, as treatment can affect fertility.

Evidence & guidelines

Its role in male hypogonadism is well established through extensive clinical use and endocrine guideline recommendations for testosterone replacement.