Tobacco, consumed mainly through smoking and smokeless forms, contains nicotine—an addictive alkaloid responsible for dependence and toxicity. Tobacco use is a leading preventable cause of disease worldwide, contributing to cardiovascular,…
Cannabis, derived from Cannabis sativa and Cannabis indica, is one of the most widely used psychoactive substances. Its active components, cannabinoids—especially delta-9-tetrahydrocannabinol (THC)—produce euphoria, altered perception, and relaxation. Although cannabis…
Lysergic acid diethylamide (LSD) is a potent hallucinogenic drug derived from ergot alkaloids. It produces profound alterations in perception, mood, and cognition. Although LSD toxicity is rarely fatal, psychological distress,…
CNS depressants include a broad category of drugs such as benzodiazepines, barbiturates, alcohols, and some sleep medications. These agents slow brain activity and are commonly used for anxiety, insomnia, and…
Opioids are potent analgesics acting on the central and peripheral nervous systems. They include natural (morphine, codeine), semi-synthetic (oxycodone, heroin), and synthetic opioids (fentanyl, methadone). While widely used for pain…
Amphetamines are potent central nervous system (CNS) stimulants used medically for ADHD and narcolepsy but widely misused for their euphoric and performance-enhancing effects. Toxicity results from excessive sympathetic stimulation and…
Arthropods—including insects and arachnids—are responsible for a large number of bites and stings worldwide. While many cause only mild local reactions, some species inject potent venom that may result in…