The male is experiencing cardinal symptoms of intoxication with marijuana: slow reflexes, paranoia, anxiety, dry mouth, and conjunctival injection.
The active ingredient in marijuana (aka: weed, pot, reefer, etc.), tetrahydrocannabinol (THC), functions by binding to the CB1/CB2 cannabinoid receptor, thereby producing the effect of euphoria, disinhibition, and decrease in pain. Intoxication with THC results largely in psychological effects such as anxiety, paranoid delusions, slowed perception of time, impaired judgment, social withdrawal, increased in appetite, and dry mouth. Aside from the use of marijuana as a recreational drug, its medicinal uses range from pain relief to glaucoma treatment to preventing nausea and vomiting in patients undergoing chemotherapy. If used often, mild withdrawal symptoms can occur (irritability, depression, and insomnia), peak at 48 hours after last use, and last for up to 5-7 days.
Volkow et al. review the adverse effects of marijuana. Short-term effects can results in impaired short-term memory and motor coordination, altered judgement increasing risky sexual behavior, and in very high doses, paranoia and psychosis. Long-term effects of marijuana can interfere with normal brain development and produce symptoms of bronchitis.
Ashton discusses the pharmacology of cannabis which contains over 60 cannabinoids, with the most potent being THC. Smoking cannabis only allows 50% of the THC to be inhaled with nearly 100% being absorbed by the lungs and reaches the brain via the bloodstream within a few minutes. THC distributes throughout the body depending on blood flow, and due to its lipophilicity, it accumulates in fatty tissue reaching peak concentrations within 4-5 days and slowly releases back into the blood with complete elimination taking up to 30 days.
Illustration A demonstrates the conjunctival injection (aka red eyes) after smoking marijuana.
Answer 1: Intoxication with PCP has the following characteristics: belligerence, impulsiveness, homicidality, psychosis, delirium, seizures, vertical and horizontal mystagmus, tachycardia, and ataxia.
Answer 2: Intoxication with cocaine has the following characteristics: grandiosity, tactile hallucination, paranoid ideations, euphoria, decreased appetite, tachycardia, and pupillary dilation.
Answer 3: Intoxication with heroin has the following characteristics: constipation, respiratory depression, pin point pupils, and seizures. When doing a physical exam, look for track marks to determine if there are needle injections versus snorting or smoking heroin.
Answer 4: Intoxication with alprazolam (a benzodiazepine) has the following characteristics: amnesia, ataxia, stupor/somnolence, and minor respiratory depression.
Volkow ND, Baler RD, Compton WM, Weiss SR. Adverse health effects of marijuana use. N Engl J Med. 2014 Jun 5;370(23):2219-27.
PMID:24897085 (Link to Abstract)
Ashton CH. Pharmacology and effects of cannabis: a brief review. Br J Psychiatry. 2001 Feb;178:101-6. Review.
PMID:11157422 (Link to Abstract)