Opioids Flashcards
✓ Natural and from phenanthrene group
Morphine, codeine, and thebaine
✓ Natural and from benzylisoquinoline
Papaverine, noscapine, and narcein.
-Semisynthetic
-More potent than morphine
-Rapid onset and shorter duration
-Not used clinically bec they are highly addictive
Heroin( diacetylmorphine) and hydromorphone
Synthetic and they are agonist
✓ Meperidine family
✓ Methadone family
✓ Tramadol
Synthetic and they are mixed agonist antagonist
Nalorphine
Nalbuphine
Pentazocine
Butorphanol
Bupernorphine
Synthetic and they are antagonist
Naloxone
Naltrexone
Bioavailability is 60%
Codein
Analgesic potency is 10-20%
Codeine
More potent cough suppressant
Codeine
Little euphoria effect
Codeine
Methylmorphine is a demethylation of morphine
Codeine
Analgesic for mild to moderate pain usually combine with paracetamol
Codeine
Used as central antitussive
Codeine
Adverse effect less than morphine
Codeine
Adverse effects:
✓ constipation
✓ RC depression
Codeine
- Synthetic and full agonist with
- Better absorbed orally and has greater bioavailability than morphine
Meperidine ( pethidine)
Analgesic potency is 10% of morphy
Meperidine (pethidine)
Used as analgesic in the following cases:
✓ Inferior myocardial infarction bec the patient has bradycardia
✓ during labour bec it is shorter in Duration and doesn’t prolong labour
Meperidine (pethidine)
✓ addiction liability but less than morphine
Codeine and Meperidine ( pethidine)
Cause histamine release and bronchoconstriction
Meperidine
Has weak atropine like actions ( dry mouth, tachycardia )
Meperidine
No GIT
NO antitussive
NO vagal stimulant effects
Meperidine
Synthetic derivatives of Meperidine
Fentanyl and alfentanil
The most potent and the shortest duration opioid agonists
Fentanyl and alfentanil
Analgesic in severe pain as long acting transdermal skin patch
Fentanyl and alfentanil
12 microgram patch =~ 30mg oral morphine daily
Fentanyl
Analgesic effect equal to morphine
Methadone
Longer duration than of morphine ( t 1/2 ) is 24h
Methadone
Used in treatment of chronic opiate and heroin users
Methadone
Can satisfy the craving need of the patient with less addictive features
Methadone
Has withdrawal symptoms less than the other opioids
Methadone
Has two different mechanisms
✓ Binds to the mu opioid receptor
✓ inhibits the re-uptake of serotonin and NA
Tramadol
Used as analgesic for moderate to severe pain ( especially musculo- skeletal pain )
Tramadol
Has relatively fewer side effects than most opioid but addiction can occur
Tramadol
May induce seizures in epileptic patients
Tramadol
Have agonist activity on kappa receptors
Nalbuphine, pentazocine, and Butorphanol
Have antagonist or partially agonist activity on mu receptors
Nalbuphine, pentazocine, and Butorphanol
Their analgesic activity and respiratory depression are less marked than morphine
Nalbuphine, pentazocine, and Butorphanol
Increase systemic and pulmonary vascular resistance lead to high cardiac load so they are contraindicated in acute myocardial infarction
Pentazocine and Butorphanol
Competitive blockers of all opioid receptors
Naloxone and naltrexone
Is given I.V and has short t 1/2 ( ~1h )
Naloxone
Could be administered orally and has longer ( t 1/2 ) 48h
Naltrexone
Can precipitate severe withdrawal syndrome if administered to opioid-addict patient
Naloxone and naltrexone
Used in treatment of acute opioid toxicity ( the adverse respiratory and CVS effects of opioids are reversed within 1-2 min and lasts for 1-2hrs
Naloxone
Is given during labour to mothers, who received opioids, to prevent neonatal respiratory depression or it can be given to the neonate via the umbilical vein
Naloxone
