1. P H R M A C O L O G Y - NOTE 9 - Opioid Analgesics (Nacrotic analgesic)
OPIOID ANALGESICS DRUGS
pure Agonist patial Agonist Atagonist
Morphine Nalorphine Pentazocainel Naloxone
Methagone
Codeine
Pholocodeine
Dextropropoxyphene
• Mu
Classes of Opioid Rs •Kappa
•Delta
Diphenoxylate
•CNS
Loperamide
place of Opioid R •Periphral tiissues
Noscapine •agonist if it is combined
partial Agonist with pure agonist.
(mixed agonist-antagonist) •antagonist if it is combined
Fentanyl with antagonist.
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2. P H R M A C O L O G Y - NOTE 9 - Opioid Analgesics (Nacrotic analgesic)
DRUG PHARMACOKINETIC USES ACTION SIDE EFFECT
Morphine Administration  Strong analgesic for chronic pain (cancer). On CNS.  Dysphoria.
 All taken by orally.  MI ACTION MECHNISM  Respiratory depression.
 Sustained release formulation.  Add with inhaler GA to produce analgesia. 1 Analgesia  Nausea & vomiting.
 Morphine is given by I.V.  Manegment for dyspnea. 2 Euphoria  prominent with pain   intra-cranial pressure.
Methadone o 75% of it, become inactive  Strong analgesic for chronic pain (cancer). 3 Dysphoria  Constipation.
Meperidine after absorption  Strong analgesic for chronic pain (cancer). 4 Resp.  sensitivity of RC to CO2  Urinary retention.
 Analgesic for labor pain. 5 Nausea stimulation of CTZ  Allergy:
Distribution
 Add with inhaler GA to produce analgesia. Vomiting  Itching.
 They are well distributed.
Pure Agonists
Codeine  Moderate analgesic for chronic pain (cancer) 6 Miosis agonize R on III c.n.  Bronchospasm.
 It is lipid soluble.
 7 Antitussive depress the CC  Tranceal rigidity(back
 They cross BBB & placenta. Cough suppression.
pain)
hydrocodeine  Moderate analgesic for chronic pain (cancer 8  BP & VD Depress VMC
Metabolism
Pholocodeine  Cough suppression On CVS. ( in large iv dose)
 By microsomal system
Dextropropoxyphen BP depress VMC  VD
 The metabolites are active.
Noscapine  Heroin (diacetylmorphine) Morphine. direct VD effect
Diphenoxylate  Codeine (Methylomorphine)  Morphine.  Treatment of diarrhea. release of histamine  VD
Loperamide  The metabolite are conjugated. On GIT.
Fentanyl  Add with inhaler GA to produce analgesia. 1 Constipa- sphincter tone
Elimination tion s.m. motility
 Mainly by kidney. 2 intra- spasm of bile duct
USES COTRA-INDICATION billary P spasm sphincter of oddi Treatment of addication
1) Analgesic for acute & chronic sever pain. 1) Head injury. On UT. Clonidine.
a. Acute pain (MI , post-operative)  Miosis. 1 spasm of ureters Control withdrawal
b. Chronic pain (cancer)   Resp. 2 Constriction of U sphincter symptom.
c. Labor pain 2) Biliary & renal colic(ex Meperidine) 3 micturation reflex
2) Cough suppression. Tolerance & Dependence. Methadone
3) Respiratory diseases.
3) Treatment of diarrhea. effect with repeated administration
 (asthma & COPD)
4) Mangment of dyspnea. 1 Analgesic Rapid tolerance
5) Analgesic with GA 4) Acute abdomen pain.
 Interfere with proper 2  Resp. Slow tolerance
a. Add with inhaler GA
diagnosis. 3 Miosis NOT develop
Acute MORPHINE poisoning 5) Pregnancy & labor (ex Meperidine) 4 constipation
Manifestation: Treatment  Addict fetus. 5 convulsion
Coma / pin point pupil 1) Artificial respiration.  Neonatal asphyxia. 6 Cross tolerance occur different agonist
Hypoventilation & hypoxia 2) Stomach wash. Addcation.
6) Liver diseases
Hypotension 3) Repeated I.V. Physical D Sudden withdrawal lead to
 Deficient metabolism
Hypothermia Naloxone Psycho. D withdrawal syndrome
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3. P H R M A C O L O G Y - NOTE 9 - Opioid Analgesics (Nacrotic analgesic)
DRUG PHARMACOKINETIC USES ACTION SIDE EFFECT
Pentazocine  Agonist on Kappa R.  Analgesia.  Dysphoria.
 Partial agonist on Mu R.  Psychomimetic effect.
 Cause weak  RC.  Anxiety.
 Mild dependency.  Nightmares.
Partial Agonists
 Mild withdrawal manifestations.  Hallucination.
 Withdrawal manifest.
with morphine addict.
Buprenorphine  Maintainance drug for opioid dependent  Psychomimetic effect.
patient.  Anxiety.
 Nightmares.
Nalorphine  Hallucination.
 Withdrawal manifest.
with morphine addict
Naloxone  Acute opiod poisoing  Reverse sever respiratory depression.
Antagonist
Pure
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