Street name: K, Special K, Katie.

Street use: Mainly snorted but can also be taken orally, smoked or injected.

Therapeutic use: Used as an anaesthetic, most commonly in emergency surgery. Has been used by some vets when treating large animals - hence its 'horse tranquilliser' tag.

Drug effect: An anaesthetic with analgesic (pain killing) and hallucinogenic properties. Takes between 30 seconds and twenty minutes to take effect depending on how it is administered. Ketamine is often described as being very 'dose specific' meaning that the effects of the drug can change quite dramatically with small increase in dosage. With small doses users describe cocaine – like energy and confidence but with higher doses users can start to become disassociated from reality (known as entering the 'k hole')

Street form: Often imported as a clear liquid but then dried into a white powder which can be snorted.

Dependency: Yes (psychological)

Withdrawal: There are no physical withdrawal symptoms but heavy users report a strong psychological dependency. Some users report severe depression and anxiety after regular, heavy use.

Long-term use: Heavy, regular users can develop a condition known as Ketamine Bladder Syndrome. The toxic effect of the ketamine can cause the bladder to reduce in size, harden and ulcerate. Symptoms include frequent need to urinate, blood in the urine and intense pain when urinating.

Prolonged use of the drug has also been linked to the development of memory problems and psychological disorders.

Overdose risk: As with any anaesthetic, inhalation of vomit (after eating) is a serious risk if doses sufficient to induce anaesthesia are taken. Mixing ketamine with drugs like alcohol can increase the risk of problems.

Legal status: In 2014 Ketamine was reclassified from a Class C to a Class B drug – mainly due to its increased popularity and concerns around bladder damage.

Maximum penalty:

For possession: 5 years and/or unlimited fine

For dealing: 14 years and/or unlimited fine.