Extreme social problems can develop from irritability, depression, and financial difficulties. Death from overdose is common, as are suicide, homicide, fatal accidents while under the influence. Snorting can be fatal in itself. Breathing is often stopped when combined doses of cocaine and heroin are taken. Lethal doses vary by individual and are not predictable.
Dependence occurs as a psychological craving and physical withdrawal process.
Unlike other drugs, intense psychological dependence is developed with even occasional low doses. Street purchases are commonly substitute or diluted drugs. The unsuspecting buyer risks having no knowledge of what he or she is taking or what the effects may be. Irregular breathing and heartbeat, respiratory and cardiac arrest. Slowed breathing may lead to oxygen starvation and brain damage.