Regular use of GHB can cause physical dependence. Withdrawal effects may include insomnia, restlessness, anxiety, tremors, sweating, loss of appetite, tachycardia, chest pain, high blood pressure, muscle and bone aches, sensitivity to external stimuli and inability to sleep. The withdrawal symptoms will subside after 2–21 days depending on the doses and frequency of use. Withdrawal from GHB may cause symptoms similar to acute withdrawal from alcohol or barbiturates (delirium tremens) and can cause convulsions, paranoia and hallucinations.
ACTIVITY 11.4
• What is GHB?• What are the sought-after effects of GHB? • What are the adverse effects of GHB? • What are the risks associated with GHB? • What are the withdrawal effects of GHB?
KETAMINE
Ketamine (Special K, green, super K, vitamin K), in powder form, appears similar to that of pharmaceutical cocaine and can act as a depressant and a hallucinogen. It is sold in either powdered or liquid form. Ketamine can be inhaled, injected or mixed in drinks. The effects are evident in about 10–15 minutes and last about one hour. It is also possible to smoke ketamine mixed with cannabis and tobacco. The drug is often mixed with other psychoactive substances such as cocaine and ecstasy to enhance their potency. With intravenous use, the onset of the effects of ketamine is immediate and reaches peak effects within minutes. Ketamine is odourless and tasteless, so it can be added to beverages without being detected, and it induces amnesia.
Ketamine is now a significant player in the UK drugs market and has widened its appeal to a larger group of partygoers. Owing to growing concern about the rising popularity as a recreational drug in Europe, Asia and North America and the misuse of the drug by medical personnel in a number of countries, the World Health Organization (WHO) Expert Committee on Drug Dependence in its thirty-third report (2003) recommended research into its recreational use or misuse.The British Crime Survey (Roe and Man 2006) reported that use of ketamine in the past year was reported by 0.3% of 16- to 59-year-olds in England and Wales. Use of ketamine in the past year was reported by 0.8% of 16- to 24-year-olds.
Legal status
Ketamine is a class C drug, which means that it is illegal to possess it and to supply it.
Therapeutic use
Ketamine is currently used in human anaesthesia and veterinary medicine.
Sought-after effects
Ketamine users report sensations ranging from a pleasant feeling of floating to being separated from their bodies. A giddy euphoria occurs with lower doses, often followed by bursts of anxiety or mood lability. Some ketamine users’ experiences involve a terrifying feeling of almost complete sensory detachment that is likened to a near-death experience. These experiences, similar to a ‘bad trip’ on LSD, are called the ‘K-hole’.
Adverse effects
Higher doses produce a withdrawn state (disassociation); when doses are higher still, disassociation (known as a ‘K-hole’) can become severe with ataxia, dysarthria, muscular hypertonicity, and myoclonic jerks. With very high doses, coma and severe hypertension may occur; deaths are unusual. Acute effects generally fade after 30 minutes. Ketamine may impair memory and aggravate existing psychosis, anxiety or depression. Prolonged use may cause disorientation and gradual detachment from the world. Ketamine produces only mild respiratory depression, and cardiovascular status is usually unaffected. In addition, ketamine has both analgesic and amnesic properties and is associated with less confusion, irrationality and violent behaviour than PCP.
A few deaths have occurred through overdose, heart or respiratory failure. With large or repeat doses hallucinations occur, for example, loss of sense of time, feeling disconnected from the body, near-death experiences. Large doses can lead to loss of consciousness. In a study of ten ketamine users, there was some evidence to suggest that long-term use may result in damage to the liver or urinary bladder, or even acute renal failure (Chu et al. 2007). However, the researchers suspect that the damage ‘may be due to other toxins that the “street ketamine” has been contaminated with’. A summary of the physiological and psychological effects of ketamine is shown in Table 11.4.
ACTIVITY 11.5
• What is ketamine?• What are the sought-after effects of ketamine? • What are the adverse effects of ketamine?
PSILOCYBIN
Psilocybin (‘magic mushrooms’) is the hallucinogenic chemical that occurs in some mushrooms. In its pure form, psilocybin is also a white powder, but it is usually sold as dried mushrooms or in substances made from mushrooms. There is a variety of wild growing fungi native to the UK and the most common one is the liberty cap. International varieties are becoming more widely available through specialist shops and the internet. Psilocybin is from the same chemical family as LSD so its effects are similar. The mushrooms can be eaten fresh, cooked or brewed into a ‘tea’. It usually takes about 30–50 mushrooms to produce a hallucinogenic experience similar to that experienced with LSD. Physical effects of psilocybin are usually experienced within 20 minutes of ingestion and can last for six hours. Other hallucinogens include Amanita muscaria (fly agaric mushrooms) and mescaline which is derived from the peyote cactus.
Legal status
Psilocybin or psilocybin-containing mushrooms are now a class A drug under the Drugs Act 2005 and ‘fungus (of any kind) which contains psilocin or an ester of psilocin’. This does not include fly agaric, which is still legal.