Somatostatin analogues stop your body from making too many hormones. They can reduce the symptoms of carcinoid syndrome and may slow down tumour growth.

What they are

Somatostatin is a protein made naturally in the body. It is made by:

• a gland in the brain (hypothalamus)
• the stomach
• the pancreas
• the bowel

Somatostatin does several things. It:

• slows down hormone production, including many of the gut hormones
• slows down the emptying of the stomach and bowel
• controls the release of hormones made by the pancreas, including insulin
• slows down or stops the release of growth hormones

If you have carcinoid syndrome, you might have a man made type of somatostatin as part of your treatment. These drugs are called somatostatin analogues. The most commonly used drugs are:

• octreotide (Sandostatin)
• lanreotide (Somatuline)

Why you have them

The symptoms of carcinoid syndrome include diarrhoea and flushing. These symptoms are caused by hormones released by the tumour.

Somatostatin analogues work by slowing down the production of hormones, particularly growth hormone and serotonin. Reducing these hormones helps to control the diarrhoea and skin flushing. They may also shrink the tumour.

How you have them

You have these drugs by injection under the skin or into the muscle. You might have them:

• 2 to 3 times a day
• once every 7 to 14 days
• once every 28 days

Most people have the injection once every 28 days to control their symptoms.

Your nurse might give you the injections. Or they might show you how to inject the drug yourself, depending on which drug you have.

Side effects

Somatostatin analogues do not usually cause many side effects. The main side effects are:

• loss of appetite
• feeling sick
• feeling bloated
• stomach pain
• tiredness (fatigue)
• increased diarrhoea (this is rare)
• soreness at the injection site

You might have raised or lowered blood sugar levels. If you are a diabetic you need to check your blood sugar more often. You might also need fewer diabetic tablets and less insulin.

Talk to your doctor or specialist nurse about any side effects you have.

Having octreotide over many months can cause gallstones. So you might have an ultrasound scan of your gallbladder before you start treatment, and then every 6 to 12 months. Between 10 and 50 out of 100 people (10 to 50%) develop gallstones while they are having octreotide. Most people have no symptoms from the gallstones.