A sharp rise in the number of Christchurch alcoholics drinking methylated spirits is worrying poison experts and alcohol counsellors.

The Christchurch City Mission is counselling six people who started drinking the household solvent in the last month.

Mission night shelter attendant Greg Lee said meths drinkers became ill rapidly.

"You watch the deterioration and it is quite shocking. It is a very addictive substance. You are hooked within three months and then you are dead within six months," he said.

Mission alcohol and drug practitioner Glenda Miller said alcoholics were turning to meths in search of a cheap "buzz".

The 100 per cent alcohol content of meths caused rapid brain and liver damage.

"They are driven to get high and many people who are addicted will drink anything that they can get down their throat without vomiting. They do it for the buzz because they have been alcohol-dependent for so long that their tolerance is such that they cannot get the buzz from it," Miller said.

One client who had recently taken up meths was previously drinking about nine litres of wine a day.

Toxicologist Dr Wayne Temple, director of the National Poisons Centre at Otago University, said methylated spirits used to have methanol added to make it undrinkable. The methanol was toxic and caused blindness, organ damage and death.

The methanol was removed in 2007 and replaced with a bitter non-toxic substance that is supposed to make it undrinkable.

"I'm surprised people are still drinking it with that bittering agent in it because it is one of the strongest you can get," he said.

Temple has called for a national review to confirm whether meths drinking is increasing.

Withdrawing meths from public sale could help solve the problem, he said.

- © Fairfax NZ News