Medroxyhexal

Generic Name: Medroxyprogesterone acetate
Product Name: Medroxyhexal

Indication

Medroxyhexal can be used in the palliative treatment of recurrent and/or metastatic breast, renal cell or endometrial cancer.

It can also be used in the treatment of visually proven endometriosis when pregnancy is the desired treatment outcome, or when surgery is contraindicated or has been unsuccessful.

Due to its ovulation-suppressing effects, a high dose of Medroxyprogesterone is also useful as a contraceptive agent. Medroxyhexal can be administered every three months for this purpose.

Action

Many cancers rely on supplies of specific sex hormones, such as oestrogen, to grow. Cancer cells have proteins called receptors on their surface which the sex hormones attach to. The easiest way to understand the significance of these receptors is to compare the process to that of a lock and key. Under normal circumstances, when the sex hormones come into contact with the receptors they fit into the lock and activate the cancer cells to divide, and the tumour grows.

Medroxyprogesterone acetate disrupts this process in some way. It may be that it prevents the cancer cells from maintaining the receptors on their surface, effectively removing the lock. Or it may have a more direct means of destroying cancer cells that has not, as yet, been identified. Medroxyprogesterone acetate is a hormonal agent that supports pregnancy. It transforms the endometrium (lining of the uterus) into the kind that supports pregnancy, it maintains pregnancy, delays labour/birth and suppresses ovulation. At high doses Medroxyhexal can be used to treat certain cancers, where it has corticoid-like activity.

Dose advice

Inoperable/recurrent/metastatic renal cell and endometrial cancer

initially 600-1200mg weekly
450-600mg every 1-4 weeks for maintenance

Breast cancer

500mg daily by IM injection
treat for at least 6 months

Endometriosis

50mg weekly or 100mg every 2 weeks by IM injection
treat for at least 6 months

Contraception

150mg every three months by deep IM injection
give first injection within 5 days of normal menstrual period
if the period between injections is greater than 14 weeks, pregnancy needs to be excluded before the next injection
the 50mg/1ml preparation is NOT to be used for contraception, the 150mg1/ml vial should be used

Administration

If volumes larger than 2.5ml are to be injected, the dose should be divided and multiple sites used, as gluteal infiltration and abscess formation may occur with large doses- long term use of cyclical oestrogens with Medroxyhexal is not recommended

Schedule

Common side effects

Menstrual irregularities:

prolonged bleeding
spotting
cessation of periods
depression
weight gain
moderate increase in blood pressure
decreased glucose tolerance

Increased appetite:

The most commonly reported side effect is an increase in appetite, causing some people to put on weight.

Nausea and indigestion:

Occasionally nausea is are present for the first few weeks of taking medroxyprogesterone acetate, but often the nausea then disappears. It can usually be relieved by taking the tablets with food and milk.

Fluid retention: