Ketamine physical effects

Physical effects of high doses of ketamine include decreased respiration and heart rate, increased blood pressure, and the possibility of vomiting and convulsions. These can lead to cardiac and respiratory arrest, coma, and death. The risk of ketamine overdose is much greater when it is mixed with other drugs such as alcohol, Ecstasy, caffeine, or cocaine. Overdoses of ketamine have been reported when people boost the drug (take another dose before the first dose wears off) to prolong its psychedelic effects. 

Ketamine hydrochloride is a synthetic drug called a dissociative anesthetic. It is a very strong hallucinogen. Its physical effects are similar to those produced by PCP (phencyclidine). Ketamine also causes the type of visual hallucinations that are often associated with taking LSD. 

In overdose, ketamine may lead to hyperthermia, seizures, hypertensive crisis, coma, and even death. These symptoms are generally thought to be caused by ketamine s catecholaminergic effects (Reich and Silvay 1989). Ketamine is physically addicting, with a described withdrawal syndrome. 

The effects of a ketamine high usually last an hour, but they can last for 4 to 6 hours, and 24 to 48 hours are generally required before the user will feel completely normal again. Effects of chronic use of ketamine may take from several months to 2 years to disappear completely. Low doses (25 to 100 mg) produce psychedelic effects quickly. Large doses can produce vomiting and convulsions and may lead to hypoxia of the brain and muscles 1 g can cause death. Flashbacks may even occur 1 year after use. Long-term effects include tolerance and possible physical and/or psychological dependence. 

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