Most prostate cancers need supplies of the male hormone testosterone to grow. Testosterone is produced by the testes and the adrenal glands. Luteinising hormone (LH) from the pituitary gland stimulates the testes to produce testosterone. LH in turn is released upon stimulation by luteinising hormone- releasing hormone (LHRH) by the hypothalamus. Buserelin, an LHRH-analogue, evokes a brief increase in testosterone levels in the first few days of starting treatment because of the increased LH release. However, the pituitary will become short of LH and the LH levels will drop soon and so the levels of testosterone fall. This may shrink or slow down the development of the cancer. During the first week of buserelin therapy antihormones are added to inhibit testosterone action.
Buserelin is given by implantation and/or nasal spray. Some patients experience some of the following side effects: hot flushes, decreased libido, gynaecomastia, weight gain, nausea and nasal irritation (in case of nasal spray application). Other side effects include headaches, dizziness, blurred vision and skin rashes.