Cocaine is a powerful central nervous system stimulant with potent cardiovascular (heart and blood vessel) side effects. Signs of intoxication typically begin with enlarged pupils, euphoria, agitation, and increased heart rate and blood pressure. With higher doses, symptoms can progress to sweating, tremors, confusion, hyperactivity, seizures, stroke , cardiac arrhythmias , and sudden death. See also related topics: drug abuse , drug abuse and dependence , drug abuse first aid , and stroke secondary to cocaine .