Snail venom painkiller

A drug that harnesses the power of deadly sea snail venom has been launched in Britain.

Prialt is a strong painkiller designed for patients suffering from chronic pain who cannot tolerate treatments like morphine.

It is based on a toxin produced by the magician's cone snail. The snail uses venom to paralyze passing fish, but scientists found chemicals in the poison could also block pain signals in the human brain.

Conus magus, or the magician's cone snail, is one of about 500 species of cone snail. It is found in tropical waters such as the Great Barrier Reef and in the South Pacific.

About 25 years ago, scientists at the University of Utah, in the US, managed to isolate a molecule from the venom that also had painkilling properties in humans.

The molecule works by preventing nerve cells from sending pain signals to the brain.

Now researchers have created a synthetic version of the compound with similar pain-killing effects, and it forms the basis of this new drug, Prialt.

Prialt is injected directly into the fluid surrounding the spinal cord through a small pump worn by the patient.

It is to be used for those suffering extreme chronic pain - such as cancer patients - for whom morphine is ineffective or unsuitable.