Drug overdose symptoms:

• abnormal pupil size
• dilated pupils (enlarged)
• pinpoint pupils (very small)
• non-reactive pupils (pupils do not change size when exposed to light)
• nausea and vomiting
• sweating
• agitation
• convulsions
• tremors
• staggering or unsteady gait (ataxia)
• difficulty breathing
• rapid breathing (tachypnea)
• shallow decreased breathing (respiratory depression)
• labored breathing
• drowsiness
• unconsciousness
• coma
• hallucinations
• terror
• delusional or paranoid behavior
• violent behavior

    Behavioral signs of drug abuse
          People abusing drugs often exhibit a variety of behavioral signs and changes. Such signs usually involve a prolonged change in mood and include irritability, depression, secretiveness, hostility, and unpredictability. A decrease in responsibility, such as missing work or school or forgetting family occasions, is another sign, as well as a sudden change in friends or hobbies. Additional behavioral changes include difficulty or refusal to communicate, as well as physical and mental deterioration. If excessive drug use continues, the person can become more demanding and intolerable, even to the extreme of committing crimes and attempting suicide.

          Your local council on drug abuse can give you more information on the behavioral signs of drug abuse.