Download
1 / 20
200 likes | 508 Views
OPIOIDS . Dr. Hisham Zein Alabdin. Plant origin. It is the dried extract of the poppy plant: Popover somniferum . Raw opium typically is composed of at least 10% morphine. Opioids. The term opioids are compounds that exert pharmacologic activity at opioids receptors.
E N D
OPIOIDS Dr. Hisham Zein Alabdin
Plant origin • It is the dried extract of the poppy plant: Popover somniferum. • Raw opium typically is composed of at least 10% morphine.
Opioids The term opioids are compounds that exert pharmacologic activity at opioids receptors. Opium derivatives: • Natural: morphine , codeine. • Semi- synthetic: heroin (Diacetyl morphine) , apomorphine. • Wholly synthetic: methadone, pethidine.
Uses • Medical: Analgesic, • Surgical. • Toxicological uses: in corrosive . Contraindications: • Age: patient less than twelve (very sensitive respiratory center). • Head injury: it masks the pupil change, it leads to increased intracranial pressure by producing vasodilatation.
Acute abdomen: it masks the sign and symptom. • Bronchial asthma:(it cause bronchospasm). • Pregnancy and delivery: (crosses placental barrier) • Liver & kidney disease .
Toxicokinetics • Absorption: are well absorbed from GIT, IM, subcutaneous. • Metabolism: it takes place in the liver undergo hepatic conjugation with glucoronic acid . • Excretion: stomach is the main excretory organ (reexcetion).
Clinical picture A-CNS Are combination of stimulation and depression. There is transient euphoria followed by dysphoria . Stimulant effects: • Chemoreceptor trigger zone nausea, vomiting • Vagus nucleus slow full pulse. • Third nerve nucleus pin point pupils.
Depressant effects: • on cerebral cortex: • Analgesia :by increasing pain tolerance and altering psychological response to pain. • Suppression of anxiety sedation. • Drowsiness, mood changes and mental cloudiness followed by sleep.
On the cough centre suppression of cough reflex. • On the respiratory centre slow, shallow (by reducing the sensitivity of respiratory centre to raised arterial CO2 tension) and apnea. • On the heat regulating centre hypothermia
On the cough centre suppression of the cough reflex e.g. codeine. • On respiratory centre slow, shallow respiration (by reducing the sensitivity of respiratory centre to raised arterial Co2 tension) and apnea. • On the heat regulating centre hypothermia
B) Cardiovascular effects: • Peripheral vasodilatations orthostatic hypotension and syncope due to release of histamine and central depression of vasomotor centre.
C) Gastrointestinal effects Mainly constipation due to: 1- Decreased gastrointestinal motility. 2- Decreased HCL secretion 3- Increased antral muscle tone and duodenal muscle tone. 4- Increased iliocecal valve and sphincter tone.
D) Biliary tract: Aggravates biliary colic by: 1- Constriction of sphincter of Oddi. 2- Increased biliary tract pressure. 3-Decreased biliary secretion.
E) Genito- urinary tract: • Increased detrusor muscle tone and increased vesicle sphincter tone urgency and retention of urine, it is aggravated by increased secretion of ADH. F) Skin: Flushing, urticaria, and skin rash.
Diagnosis • By circumstantial evidence • History • Clinical examination: • CNS depression, miosis, hypothermia and respiratory depression.
Differential diagnosis • Other toxic coma (parathione). • Traumatic and pathological coma with miosis the most important is coma due to pontinehaemorrhage.
Investigation • TLC It gives a positive result about 30 minutes after a single dose and remains +ve up to 36 hrs and up to 72 hrs after repeated doses.
Treatment • A B C • Prevent further absorption • Narcotic antagonists: • Pure narcotic antagonist: Naltrexone, Naloxone(Narcan). • Mixed narcotic agonist-antagonist: Not used
Disadvantages of mixed agonist-antagonist • So they can produce synergism with opiates and aggravate respiratory depression. • In non opiate poisoning, they produce symptoms and signs like opiate toxic effects. • In addicts they produce severe withdrawal syndrome.
Cause of death • Central asphyxia
