Cannabis, also known as marijuana among other names,[a] is a psychoactive drug from the Cannabis plant used for medical or recreational purposes.The main psychoactive part of cannabis is tetrahydrocannabinol (THC), one of 483 known compounds in the plant, including at least 65 other cannabinoids. Cannabis can be used by smoking, vaporizing, within food, or as an extract.Encyclopedia Entry for Marijuana :Marijuana intoxication. The intoxicating effects of marijuana include relaxation, sleepiness, and mild euphoria (getting high). Smoking marijuana leads to fast and predictable signs and symptoms. Eating marijuana can cause slower, and sometimes less predictable effects. Marijuana can cause undesirable side effects, which increase with higher doses. These side effects include: Decreased short-term memory Dry mouth Impaired perception and motor skills Red eyes More serious side effects include panic, paranoia, or acute psychosis , which may be more common with new users or in those who already have a psychiatric disease. The degree of these side effects varies from person to person, as well as with the amount of marijuana used. Marijuana is often cut with hallucinogens and other, more dangerous drugs that have more serious side effects than marijuana. These side effects may include: Sudden high blood pressure with headache Chest pain and heart rhythm disturbances Extreme hyperactivity and physical violence Heart attack Seizures Stroke Sudden collapse (cardiac arrest).Treatment and care involves: Preventing injury Reassuring those who have panic reactions due to the drug Sedatives, called benzodiazepines, such as diazepam (Valium) or lorazepam (Ativan), may be given. Children who have more serious symptoms or those with serious side effects may need to stay in the hospital for treatment. Treatment may include heart and brain monitoring. In the emergency department, the patient may receive: Activated charcoal, if the drug has been eaten Blood and urine tests Breathing support Chest x-ray ECG (electrocardiogram, or heart tracing) Fluids through the vein (intravenous, or IV) Medicines to relieve symptoms (see above).Uncomplicated marijuana intoxication rarely needs medical advice or treatment. Occasionally, serious symptoms occur. However, these symptoms are rare and usually associated with other drugs or compounds mixed in with marijuana.If someone who has been using marijuana develops any of the symptoms of intoxication, has trouble breathing, or cannot be awakened, call 911 or your local emergency number. If the person has stopped breathing or has no pulse, begin cardiopulmonary resuscitation (CPR) and continue it until help arrives.Cannabis intoxication; Intoxication - marijuana (cannabis); Pot; Mary Jane; Weed; Grass; Cannabis.Brust JCM. Effects of drug abuse on the nervous system.