[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Environmental pathology](https://durgical.com/en/general-pathology/#a-environment) › Drugs of abuse: cocaine, opioids, amphetamines, cannabis [General pathology](https://durgical.com/en/general-pathology/) · [Environmental pathology](https://durgical.com/en/general-pathology/#a-environment) # Drugs of abuse: cocaine, opioids, amphetamines, cannabis - Topic Drugs of abuse injure the heart, brain, lungs and other organs through their action on neurotransmitters and through the way they are used. Updated 2026-11-01 ## Key points - Cocaine: vasospasm and catecholamine excess → MI, stroke, aortic dissection; nasal septal perforation when snorted. - Opioid overdose triad: coma, miosis, respiratory depression. - Injection drug use → tricuspid valve endocarditis by Staphylococcus aureus. - MDMA: hyperthermia, hyponatraemia and serotonin syndrome. - Cocaine in pregnancy: placental abruption and fetal growth restriction. ## What it is Each drug has its own main target. Stimulants such as cocaine and amphetamines flood synapses with catecholamines and constrict vessels; opioids depress breathing; cannabis acts on cannabinoid receptors. Injecting, snorting or smoking adds infections, burns and airway injury, and use in pregnancy harms the newborn. ## Step by step - Cocaine blocks the reuptake of noradrenaline, dopamine and serotonin; amphetamines release them. - Excess catecholamines raise heart rate and blood pressure and constrict coronary and cerebral arteries. - Vasospasm, faster atherosclerosis and thrombosis cause myocardial infarction and stroke, even in young people. - Sudden surges of blood pressure can tear the aorta or rupture brain vessels. - Opioids act on mu receptors in the brainstem: breathing slows, the brain becomes hypoxic and the lungs fill with fluid. - Unsterile injection brings Staphylococcus aureus to the right-sided heart valves and spreads HIV and hepatitis C. ## What each drug does to tissue | Drug | Main action | Typical injury | | --- | --- | --- | | [Cocaine](https://durgical.com/en/conditions/cocaine-and-sympathomimetic-toxicity/) | Blocks catecholamine reuptake; local vasoconstriction | Infarction, stroke, aortic dissection, arrhythmia, nasal septum perforation, placental abruption | | [Amphetamines and methamphetamine](https://durgical.com/en/conditions/stimulant-use-disorder/) | Releases catecholamines | Hypertension, cardiomyopathy, psychosis, severe dental decay; MDMA: hyperthermia and hyponatraemia | | [Opioids (heroin, fentanyl)](https://durgical.com/en/conditions/opioid-overdose/) | Mu-receptor agonism | Respiratory depression, pulmonary oedema, endocarditis, skin abscesses, neonatal abstinence | | [Cannabis](https://durgical.com/en/conditions/cannabis-toxicity-and-cannabinoid-hyperemesis-syndrome/) | CB1 receptor agonism (THC) | Cyclic vomiting (hyperemesis), psychosis in vulnerable youth, airway irritation when smoked | ## Clinical notes - Chest pain in a young adult without risk factors raises the question of cocaine use. - Opioid overdose: coma, pinpoint pupils and slow breathing; naloxone reverses it quickly. - Stimulant toxicity may cause hyperthermia, rhabdomyolysis and kidney injury. ## Memory aid Stimulants squeeze the arteries and speed the heart; opioids silence the breathing. ## Test yourself Think of the answer, then tap the question to see it. ## How does cocaine cause myocardial infarction in a young person? It blocks catecholamine reuptake: coronary vasospasm, higher oxygen demand, platelet activation and thrombosis. ## Which heart valve is most often infected in people who inject drugs? The tricuspid valve, most often by Staphylococcus aureus from the skin, with septic emboli to the lungs. ## What are the three classic signs of opioid overdose? Depressed consciousness, pinpoint pupils and slow, shallow breathing. ## Which local lesion is typical of repeated snorting of cocaine? Ischaemic necrosis and perforation of the nasal septum from repeated vasoconstriction. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/general-pathology/drugs-of-abuse-cocaine-opioids-amphetamines-cannabis/) ## Related - [Tobacco: how smoking injures tissue](https://durgical.com/en/general-pathology/tobacco-how-smoking-injures-tissue/) - [Alcohol: how it injures the liver, brain, heart and fetus](https://durgical.com/en/general-pathology/alcohol-how-it-injures-the-liver-brain-heart-and-fetus/) - [Infarction: red vs white, and what decides the damage](https://durgical.com/en/general-pathology/infarction-red-vs-white-and-what-decides-the-damage/) ## Related conditions - [Cocaine and sympathomimetic toxicity](https://durgical.com/en/conditions/cocaine-and-sympathomimetic-toxicity/) - [Opioid overdose](https://durgical.com/en/conditions/opioid-overdose/) - [Stimulant use disorder (cocaine, amphetamines)](https://durgical.com/en/conditions/stimulant-use-disorder/) - [Opioid use disorder, overdose and withdrawal](https://durgical.com/en/conditions/opioid-use-disorder-overdose-and-withdrawal/) - [Cannabis toxicity and cannabinoid hyperemesis syndrome](https://durgical.com/en/conditions/cannabis-toxicity-and-cannabinoid-hyperemesis-syndrome/) - [Cannabis use disorder](https://durgical.com/en/conditions/cannabis-use-disorder/) - [Hallucinogen and dissociative drug intoxication (LSD, PCP, ketamine)](https://durgical.com/en/conditions/hallucinogen-and-dissociative-drug-intoxication/) - [Infective endocarditis](https://durgical.com/en/conditions/infective-endocarditis/) - [Myocardial Infarction (Heart Attack)](https://durgical.com/en/conditions/myocardial-infarction/) - [Aortic dissection](https://durgical.com/en/conditions/aortic-dissection/) - [Intracerebral haemorrhage](https://durgical.com/en/conditions/intracerebral-haemorrhage/) - [Placental abruption](https://durgical.com/en/conditions/placental-abruption/) - [Neonatal abstinence syndrome](https://durgical.com/en/conditions/neonatal-abstinence-syndrome/) - [Rhabdomyolysis](https://durgical.com/en/conditions/rhabdomyolysis/) - [Serotonin syndrome](https://durgical.com/en/conditions/serotonin-syndrome/) ## Elsewhere in DurgiPedia - [The main neurotransmitters](https://durgical.com/en/physiology/the-main-neurotransmitters/) - [Synaptic transmission](https://durgical.com/en/physiology/synaptic-transmission/) - [Coronary circulation and myocardial ischemia](https://durgical.com/en/physiology/coronary-circulation-and-myocardial-ischemia/) ## Microorganisms - [Staphylococcus aureus](https://durgical.com/en/microbiology/staphylococcus-aureus/) ## In Pharmacology - [Naloxone](https://durgical.com/en/pharmacology/naloxone/) - [Methadone](https://durgical.com/en/pharmacology/methadone/) - [Buprenorphine](https://durgical.com/en/pharmacology/buprenorphine/) [← All of general pathology](https://durgical.com/en/general-pathology/) Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Cocaine intoxication: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000946.htm) (MedlinePlus, US National Library of Medicine, 2026); [Opioids and Opioid Use Disorder (OUD): MedlinePlus](https://medlineplus.gov/opioidmisuseandaddiction.html) (MedlinePlus, US National Library of Medicine, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/general-pathology/drugs-of-abuse-cocaine-opioids-amphetamines-cannabis/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/drugs-of-abuse-cocaine-opioids-amphetamines-cannabis/