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Acetaminophen (paracetamol) pharmacology

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Use the PharmacoPhoto video ‘flash-card’ series to reinforce your knowledge of drug classes and specific medications.

And thanks for joining me as we get a drug picture of paracetamol or in the united states acetaminophen paracetamol or acetaminophen is a medication that’s used to treat pain and fever paracetamol or acetaminophen is not classified as a anti-inflammatory agent it’s classified as a mild analgesic a paracetamol was discovered in 1877 and after all this time

We still don’t know how it works we had thought that it was a enzymatic inhibition of cyclooxygenase 3 and then it worked centrally only but recent studies have cast a lot of doubt on it working on any enzymes so unfortunately we’re not going to get a real clear picture of how it works but we’ll still get a good picture of what it does we can say with near

Certainty that acetaminophen or paracetamol does not work in the periphery like the non-steroidal anti-inflammatory drugs recall how we have three what we term orders of neurons in the pain pathway so the first order of neurons is going to go in the extremities up into the spinal cord the second order of neurons goes from the spinal cord to the thalamus and

The third order of neurons travels takes that message over to the brain and there it’s going to be interpreted we also have an inhibitory pathway which goes from the brain down to the level of the spinal cord and whatever points that that first and second order of neurons met that point is a gate basically a gate and at that gate we have the ability to put some

Inhibition or inhibitory post-synaptic potentials in that area and we think that acetaminophen or paracetamol actually works around that area at least that’s where most of the research is being done acetaminophen at this point paracetamol is said to be useful for the relief of mild to moderate pain but like all analgesics the efficacy of paracetamol is variable

Not only between different conditions but also between different individuals so for instance non-steroidal anti-inflammatory drugs including aspirin and ibuprofen are thought to be generally a lot better at relieving pain that involves inflammation for instance pain from rheumatoid arthritis and then some individuals will receive pain relief from a condition for

Instance osteoarthritis with the paracetamol or acetaminophen and then others will not so it’s important to switch to a different analgesic if there is no pain relief paracetamol is also regarded as an anti pyrogenic agent or in other words it’s said to decrease favor one of the most important adverse effects of paracetamol is liver damage paracetamol toxicity

Is the foremost cause of acute liver failure in the western world it’s caused by a number of different things first of all paracetamol is oftentimes in medications with opioids and somebody wants to like overdo the opioids they actually get liver toxicity doing that another possibility is that somebody is not realizing that they’re taking paracetamol in several

Different cold and flu remedies that they’re taking simultaneously and another possibility is that they don’t metabolize the paracetamol very well so for instance the half-life of paracetamol or acetaminophen is anywhere between one and four hours depending on the individual so someone who metabolizes the drug very slowly is going to be at greater risk of hepatic

Damage and now you understand that paracetamol also known as acetaminophen in the united states is a medication that’s used to treat pain and fever paracetamol is used for the relief of mild to moderate pain but one must remember that no analgesic is going to be effective in all people and no analgesic is going to be effective for all conditions so the smallest

Dose for the shortest period of time is most appropriate well paracetamol or acetaminophen does not harm the gi t or the kidneys to the same degree as the non-steroidal anti-inflammatory drugs and it doesn’t affect platelet aggregation in the same way that the non-steroidal anti-inflammatory drugs do it’s important to remember that it is toxic to the liver and

It can cause serious liver damage if more than the recommended dose is used and now you know thanks for joining me you

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Acetaminophen (paracetamol) pharmacology By PharmacoPhoto