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  #1  
Old 12-16-2009
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Drug Pharmacology of opiates

A patient known to be a heroin abuser comes to ER with a painful stab wound . The ER physician administers Nalbuphine for the pain. Why is this not a good idea?

a. The patient is probably tolerant to Nalbuphine.
b. The drug may precipitate a withdrawal state.
c. Nalbuphine is a weaker analgesic than codeine .
d. Vasodilating effects of nalbuphine increase blood loss .
e. Nalbuphine is a strong miu receptor agonist .
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Old 12-16-2009
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I think the answer is B
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Old 12-18-2009
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codeine because it's partial agonist
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Old 12-22-2009
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Default pharmacology of opiates

Answer is B.

Nalbuphine is an agonist at kappa opioid receptors and an antagonist at miu opioid receptors.

Mixed agonist -antagonist can displace miu receptor
agonists such as heroin from receptors, resulting in rapid development of symptoms of withdrawal in patients who are physically dependant on such drugs .

Nalbuphine is superior to Codeine as an analgesic .
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Old 12-29-2009
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usmlerx Qmax ques!!!!!
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Old 07-07-2010
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Post opioid

nalbuphine is a synthetic opioid and it will cause a withdrawal reaction in heroin addict because it resembles structurally to narcotic antagonist naloxone..but it can be used as an analgesic because of structural resemblance to oxymorphone!! only trick is not to use it in an opioid addict..
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Old 07-07-2010
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Default opioid pharmacology

Quote:
Originally Posted by faith View Post
nalbuphine is a synthetic opioid and it will cause a withdrawal reaction in heroin addict because it resembles structurally to narcotic antagonist naloxone..but it can be used as an analgesic because of structural resemblance to oxymorphone!! only trick is not to use it in an opioid addict..
Naloxone is an antagonist at the mu -opioid receptor.

Naloxone chemical structure is similar to Oxymorphone the only difference is the substitution of N-methyl group with allyl from where the name:Naloxone-derived from N-allyl & Oxymorphone.

Naloxone is distributed to heroin users to reduce the rates of fatal overdose.
For Nalbuphine please see the previous poster .
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Old 07-09-2010
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Default i think

ans should be --a--pt is known abuser so tolerance level..
cant be withdrwal state as it dosent sates that pt have left heroin.. he still does it..
cant be c--its def stronger than codiene.. codiene is oct at least in india..
cant be d..its u antagonist:sorry:
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Old 07-09-2010
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Default opioid pharmacology

Quote:
Originally Posted by gayfish View Post
ans should be --a--pt is known abuser so tolerance level..
cant be withdrwal state as it dosent sates that pt have left heroin.. he still does it..
cant be c--its def stronger than codiene.. codiene is oct at least in india..
cant be d..its u antagonist:sorry:
The corect answer is B

Pls see explanation in the post above.
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Old 07-09-2010
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Quote:
Originally Posted by Laurentiu View Post
The corect answer is B

Pls see explanation in the post above.
but he question states -- patient known to be a heroin abuser..
are you sure the ans is b..
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  #11  
Old 07-09-2010
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Correct Answer opioid pharmacology

I think this concept has already been explained but any how

The correct answer is

b. The drug may precipitate a withdrawal state.

Explanation

Heroin is metabolized in the body to morphine and other metabolites which are all mu receptor agonists.
Nalbuphine is kappa agonist & mu antagonist.

Mixed agonists-antagonists (nalbuphine) can displace mu receptor agonists (heroin) from receptors, resulting in the rapid development of symptoms of withdrawal in pts who are physically dependant on these drugs...a phenomenon called precipitated withdrawal.

---------------------------------------
*Source Kaplan Pharma lecture Notes
----------------------------------------

Quote:
Originally Posted by gayfish View Post
ans should be --a--pt is known abuser so tolerance level..
cant be withdrwal state as it dosent sates that pt have left heroin.. he still does it..
As the pt is a known abuser so he must have physical dependence. This means he still has heroin in his system which will be displaced if he is given Nalbuphine.

Although cross tolerance does occur between opioids, in the relief of pain this can be overcome by increased dosage.

I hope this concludes it.....
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