This interesting ppt is the continuation of the Pharmacology of Opioid analgesics I... This impressive ppt highlight the pharmacology, advantages and disadvantages of opioid analgesics other than morphine with illustrations....!!

1. Dr. V. SATHYANARAYANAN M.B.B.S., M.D., ACME
PROFESSOR OF PHARMACOLOGY
SRM MCH & RC, KATTANKULATHUR, CHENNAI, INDIA
*

15. *
*Morphine is the prototype of opioid analgesics
*It is Very useful in severe visceral pain, Though it has many
side effects
*It acts on opioid receptors
*Long term use cause tolerance and dependence
*Naloxone is the specific antidote for morphine poisoning
*Respiratory depression and hypotension has to be watched
for during morphine use

18. *
*Semisynthetic drug
*Diacetylmorphine
*Converted into morphine in the body
*Greater and faster euphoria
*Higher abuse potential
*Banned in many countries
*Can be used for continuous pain control in
palliative care

28. *
*Naturally occurring opium alkaloid
*Less potent than morphine ( 1/10th as analgesic)
*Depresses cough in subanalgesic doses
*Less constipating and respiratory depressant
*Less addiction liability
*Used as antitussive and in diarrhoea
*Combined with paracetamol for analgesia

35. *
*Semisynthetic opioids
*Have codeine like properties
*Antitussives
*Less constipating

37. *
*Semisynthetic opioid
*Controlled release tab for cancer and other
chronic pain
*Higher systemic availability

41. *
* recently developed Synthetic codeine analogue
*Atypical opioid
*Weak opioid agonist
*Also blocks reuptake of serotonin, NA in the CNS  additional
mechanism for pain relief
*Good oral bioavailability
*Generally well tolerated
*Cause sedation, dry mouth, nausea, mild respiratory depression
* may precipitate seizures
*Drug of dependence, but low abuse potential
*Avoided with MAO inhibitors, SSRIs ( serotonin syndrome )
*Used in mild to moderate acute and chronic pain
*Not for severe pain

47. *
*Similar to tramadol
*Inhibition of NET is more marked than SERT
*Effective in moderately severe pain
*Less nausea and vomiting
*Risk of seizures and serotonin syndrome
*Useful alternate to tramadol

51. *
*1/10th as potent as morphine
*Efficacy is equal to morphine
*More rapid onset of action & shorter duration of action
after I.M injection
*Does not effectively suppress cough
*Also has anticholinergic effects ( dry mouth, blurring of
vision)
*May produce negative inotropic effect

53. *
*Similar to morphine
*Less constipation & urinary retention
*Dry mouth, blurred vision, tachycardia
*Serotonin syndrome
*Toxic doses  sometimes produces CNS stimulation with
* tremors
*Restlessness
*Convulsions
*Because of norpethidine

58. *
*Analgesic in visceral pain
*( preferred over morphine because of better
oral efficacy & less spasmogenic action )
*Obstetric analgesia ( less apnoea, no effect on
uterus )
*Preanaesthetic medication

65. *
*Fentanyl and its congeners ( sufentanil,
alfentanil, remifentanil )
*Alphaprodine
*Diphenoxylate
*Loperamide

66. *
*100 times more potent than morphine as analgesic and
respiratory depression
*Fast acting ( max effect within 5 minutes after I.V
Injection) but duration shorter (30-40 minutes )
*Mild effects on CVS
*Does not increase intracranial pressure
*Does not release histamine
*Available as transdermal patches ( act for 48 hours ) and
buccal preparation
*Commonly used opioid analgesic

71. *
*In neuroleptanalgesia for short surgical procedures
*Postoperative analgesia, Obstetric analgesia ( epidural
fentanyl )
*Cancer/terminal illness pain
*Also used in chronic pain where opioid use is permissible

76. *
*Nausea, vomiting,
*respiratory depression
*Bolus doses cause muscle rigidity

79. *
*alfentanil, remifentanil are faster acting ( act
within a minute )
*Recovery is rapid
*Used for short surgical procedures
*Diphenoxylate , Loperamide  used in
diarrhoeas

83. *
*Synthetic opioid
*Mu receptor agonist
*Also blocks NMDA receptors
*Blocks monoaminergic receptor uptake transporters
*Has high oral:parenteral ratio ( 1:2 )
*90% plasma protein bound
*Gradually accumulates

85. *
*Actions similar to morphine
*Effective analgesic
*Relieves even certain type of neuropathic pain,
cancer pain
*Longer duration of action ( t1/2 24-36 hours )
*Effective by many routes ( oral, rectal, SC, IV,
Spinal routes )
*Less abuse potential

89. *
*Substitution therapy : in opioid dependence
*Methadone maintenance therapy in opioid addicts
*As an analgesic
*Caution --- may predispose to arrhythmias
*LAAM  is a derivative of methadone with longer
duration of action than methadone

91. *
*A congener of methadone
*Binds to opioid receptors with similar actions to morphine
*Less constipating
*Longer acting
*Good oral bioavailability
*Used in mild to moderate pain
*Several deaths have been reported ( rapid absorption 
respiratory arrest, hypotension )
* has abuse potential
*Low efficacy
*BANNED IN INDIA, UK, EUROPE, USA ( CARDIOTOXICITY,
DELIRIUM, SEIZURES )

96. *
*Related to pethidine
*Mild analgesic effects
*Low addiction potential
*Used orally in combination with NSAIDs
*EQUAGESIC – aspirin 325mg + ethoheptazine75mg
1tab tds

100. *COMPLEX ACTION OPIOIDS

102. *
*Analgesics of limited efficacy
*Equivalent to lower doses of morphine
*AGONIST-ANTAGONIST DRUGS
*Cause submaximal respiratory depression
*Less addicting
*Should not be administerd to patients who
receieved Mu opioid agonist  May cause
withdrawal symptoms in addicts

104. *
*Pentazocine
*Cyclazocine
*Nalbuphine
*Buprenorphine
*Butarphanol
*Nalorphine

105. *
*Kappa receptor agonist, weak mu antagonist
*½ potent as morphine
*Cause primarily spinal analgesia
*Sedation, respiratory depression are less marked
*Increases BP and heart rate ( not suitable for MI )
*Less biliary spasm and constipation
*Less abuse liability
*Not a favoured analgesic now
*May be used for postoperative pain, moderately severe pain
in burns, trauma, fractures, cancer, etc

108. *
*Sedation
*Dizziness
*Sweating
*Nausea
*Dysphoria with anxiety
*Nightmares, hallucinations
*Tolerance and dependence develops on repeated
use
*IM injections painful, sterile abscess may come

112. *
*Analogue of naloxone
*Strong Kappa agonist with weak mu antagonist
*More potent analgesic than pentazocine
*Produces few dysphoric or psychotomimetic effects than
pentazocine
*Does not cause sympathetic stimulation, no cardiovascular effects (
safe in MI )
*Has a ceiling effect for analgesia and respiratory depression at
30mg IM
*Low abuse potential
*Useful in moderately severe pain, post operative pain
*10-20 mg IM

115. *
*Synthetic thebaine congener
*Partial mu agonist
*25 times as potent as morphine
*Slow onset of action but long duration of analgesia
*Repeated use cause accumulation
*Less respiratory depression
*Lower tolerance and dependence
*Mild and late withdrawal symptoms
*Useful in Chronic painful conditions like that in terminal
cancer patients

118. *
*Highly lipid soluble
*Extensive 1st pass metabolism
*Given sublingually or IM or IV
*Also transdermally

123. *
*For long-lasting painful conditions ( cancer pain )
*Premedication,
*post operative pain
*MI
*Treatment of morphine dependence ( alternative to
methadone )
*NOT SUITABLE FOR USE DURING LABOUR

125. *
*Similar and more potent than pentazocine
*Causes tachycardia but does not increase BP
*Milder dysphoria
*1-2 mg IM/IV

126. *
*Low doses good analgesic
*but no increased analgesia with increase in dose
*Causes dysphoria ( K agonist ) and respiratory
depression even in low doses
*Cannot be used as an analgesic
*High doses act as an antagonist and counters all
actions of opioids
*May be used in acute opioid poisoning
*Also used for the diagnosis of opioid addiction

130. *
*Short acting agonist – antagonist with
anticholinergic actions
*Short duration of analgesia with less
respiratory depression
*Low incidence of confusion and abuse
*Suitable for obstetric analgesia

133. *
*Naloxone
*Naltrexone
*Nalmefene

134. *
*Pure antagonist
*For all 3 opioid receptors
*Normal people --- no actions
*Opium addicts – antagonises all actions of
morphine
*Blocks actions of endo.opioid peptides
*Dose – 0.4 mg IV
*Acts for 1-2 hours

135. *
*Drug of choice for morphine overdosage
*To reverse neonatal asphyxia due to opioids
during labour
*Diagnosis of opioid dependence
*Hypotension during shock

139. *
*More potent pure opioid antagonist
*Orally effective
*Longer duration of action ( 1-2 days)
*Used for opioid blockade therapy in post
addicts
*Used to prevent relapse of heavy drinking as it
Reduces alcohol craving

146. *
*Derivative of naltrexone
*Orally effective and long acting
*Not hepatotoxic
*Used in opioid over dosage

149. *
*Several synthetic and semisynthetic opioids are
available
* some are more potent than morphine
*They afford several pharmacokinetic and
pharmacodynamic advantages over morphine
*The adverse effects also less with them
*Opioid antagonists are also useful therapeutically
*Short acting drugs are preferred for for acute pain
*Opioid rotation for chronic pain

159. *THANK YOU…