b)
Classify heroin and briefly explain how the problem above can develop. (3 marks)
Heroin – strong opioid agonist Chronic use physiologic and psychological dependence. Physiological dependence abstinence syndrome when abruptly withdrawn c)
What drug can the doctor use to reduce the severity of his symptoms? Explain the mechanism. (3 marks)
Methadone Long half-life longer acting than heroin. When withdrawn, the drug concentration in the body declines more slowly than heroin, so the withdrawal syndrome is less svere and less sudden. After 3 days of admission, the patient was found missing from the hospital and a missing persons report was lodged with the police. Two weeks later he was found unconscious by the roadside and was brought to hospital by strangers. On examination, he was found to have respiratory depression. d)
What is the reason for his respiratory depression? What is the receptor subtype involved in this complication. (1½ mark)
Heroin overdose μ receptor e)
What drug can the doctor use to reverse his respiratory depression? Briefly explain the mechanism. (1½ mark)
Naloxone Opoid antagonist at all the receptors μ, κ, δ
213