Indications
Testosterone Isocaproate is a form (ester) of the male hormone testosterone. It is mainly found as one part of mixed testosterone injections, where several esters are combined so that the hormone is released over a few weeks. These injections are used to treat men whose bodies do not make enough testosterone (male hypogonadism), which can cause low sex drive, erection problems, tiredness, loss of muscle and bone and delayed puberty.
How It Works
After injection into a muscle, the isocaproate ester is slowly broken down to release testosterone. It acts at a medium speed, filling the gap between the fast-acting and slow-acting esters in a mixed injection. Testosterone then works on the body like natural male hormone, supporting male sexual features, muscle, bone, red blood cell production and sex drive.
Dosage and Administration
This is a hormone injection given deep into a muscle by a doctor or nurse. The dose and how often it is given (often every few weeks) are decided by the doctor as prescribed, based on symptoms and blood tests. Do not use it to build muscle or improve sports performance.
Interactions
- Warfarin and other blood thinners: bleeding risk may increase; blood tests are needed.
- Insulin and other medicines for diabetes: blood sugar may fall, doses may need adjusting.
- Corticosteroids (such as Prednisolone): more fluid retention and swelling.
Contraindications
Do not use in men with prostate cancer or male breast cancer, in people with high blood calcium linked to cancer, in pregnancy or breastfeeding, or if allergic to any ingredient (some injections contain peanut oil, so people allergic to peanut or soya should not use them). Not for use in women and children unless a specialist decides.
Side Effects
- Acne, oily skin and increased body hair.
- Pain or swelling at the injection site.
- Fluid retention, weight gain and raised blood pressure.
- Higher red blood cell count (thick blood), mood changes, breast swelling.
- Reduced sperm count and smaller testicles during use; worsening of sleep apnoea.
Get urgent medical help if you have chest pain, sudden breathlessness, pain or swelling in one leg, weakness on one side of the body, yellow skin or eyes, a painful erection lasting more than 4 hours, or a severe allergic reaction.
Pregnancy and Lactation
Must not be used in pregnancy or breastfeeding, as it can cause male features to develop in a female baby. Women should avoid contact with the medicine.
Precautions and Warnings
Your doctor will check blood counts, prostate health (PSA), liver tests and cholesterol during treatment. Tell your doctor if you have heart, kidney or liver disease, high blood pressure, epilepsy, migraine, diabetes or sleep apnoea. Misuse at high doses can cause heart problems, liver damage, infertility and mood disturbance. In boys it can close the growth plates early, so it is used only by specialists.
Overdose
A single extra dose is unlikely to cause serious harm, but repeated high doses can lead to thick blood, fluid retention and other side effects. Contact your doctor if you think too much has been given.
Therapeutic Class
Androgen (male sex hormone).
Storage
Store below 30°C, away from light, do not refrigerate, and keep out of the reach of children. In hospital, store as directed on the pack.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.