Cocaine is a powerful CNS stimulant. It rapidly increases levels of neurotransmitters like dopamine, norepinephrine, and serotonin by preventing their reabsorption in the brain. These effects trigger elevated heart rate, blood pressure, and body temperature, which can quickly progress to life-threatening conditions.
Impact on the Heart and Blood Vessels
Cocaine profoundly affects the cardiovascular system by increasing sympathetic nervous system activity. This overstimulation causes an accelerated heart rate, elevated blood pressure, and increased heart muscle contractility.
Cocaine use causes vasoconstriction, narrowing blood vessels and restricting blood flow. This is dangerous in coronary arteries, as it reduces oxygen supply to the heart muscle. The imbalance between the heart’s increased oxygen demand and reduced supply can lead to myocardial ischemia or a myocardial infarction (heart attack). Cocaine also promotes platelet clumping and blood clot formation, which can block coronary arteries and contribute to heart attacks.
Cocaine can disturb the heart’s electrical system, leading to abnormal heart rhythms (arrhythmias). These include dangerously fast heartbeats like ventricular tachycardia and ventricular fibrillation, which can result in sudden cardiac arrest. Severe hypertension and vasoconstriction in the brain’s blood vessels can also cause a stroke, either ischemic (due to a clot) or hemorrhagic (due to bleeding).
Another severe cardiovascular complication is acute aortic dissection, a tear in the body’s main artery, the aorta. This condition is often triggered by sudden, extreme spikes in blood pressure induced by cocaine, which can weaken vessel walls. Aortic dissection is a life-threatening event.
Impact on the Brain and Nervous System
Cocaine’s effects on the brain and nervous system stem from excessive neurotransmitter signaling across neural pathways. This overstimulation disrupts normal brain activity, which can result in neurological events.
One significant neurological consequence is seizures. Cocaine lowers the brain’s seizure threshold, making individuals more susceptible, even without a prior history of epilepsy. While many cocaine-associated seizures are self-limited, prolonged or repeated seizures without recovery, known as status epilepticus, can occur. Status epilepticus is a medical emergency that can lead to brain damage, severe respiratory issues, and multi-organ failure.
Although cocaine is a stimulant, severe intoxication can indirectly suppress the central nervous system’s control over breathing. This can lead to acute respiratory failure, where the lungs cannot adequately exchange oxygen and carbon dioxide. This respiratory depression can result from direct neurological effects or as a complication of prolonged seizures.
Cocaine also interferes with the body’s ability to regulate temperature, causing a significant increase in core body temperature, known as hyperthermia. This elevated temperature is often exacerbated by increased muscular activity and the drug’s vasoconstrictive effects, which hinder heat loss. Severe hyperthermia can cause widespread cellular damage and organ dysfunction, leading to organ failure and death.
Other Acute Physiological Failures
Beyond direct cardiovascular and neurological effects, cocaine can trigger other acute systemic failures. These complications often arise from initial physiological stress, representing distinct pathways to death.
One such pathway involves rhabdomyolysis and acute kidney injury. Prolonged seizures, extreme agitation, or severe hyperthermia induced by cocaine can cause muscle tissue breakdown. This process releases myoglobin and other harmful substances into the bloodstream. These toxic byproducts overwhelm the kidneys, impairing their ability to filter waste and leading to acute kidney failure.
Cocaine intoxication can cause direct liver damage, resulting in acute liver injury. This can progress to liver failure, a condition where the liver loses its ability to perform essential functions, including detoxification and protein synthesis.
Cocaine use can also lead to acute respiratory distress syndrome (ARDS). This severe lung condition involves fluid accumulation in the lung’s air sacs (non-cardiogenic pulmonary edema) or direct lung tissue injury. ARDS severely impairs the lungs’ ability to transfer oxygen into the bloodstream, leading to profound oxygen deprivation and significant breathing difficulties. This respiratory compromise can be fatal.