What's the difference between aspirin, acetaminophen, and ibuprofen... and what's best for pain relief?

Question

What is the difference between the three drugs?

Which is best (safest & most effective) for general pain relief?

Answer 1

All these drugs are mostly anti-inflammatory medications with very weak pain relief effect. Aspirin has also very strong anti-fever effect.

To relieve pain it is better to use special class of drugs, painkillers (of course if your pain is not caused by an inflammation). About most popular pain killers you can read here http://bisina.info/order_pain_relief_en-...

Answer 2

All three drugs have different chemical structures, with aspirin having the most basic structure.

Aspirin is a prodrug, one that has to be metabolised before it becomes active. The other two are already active in their normal form.

Aspirin and ibuprofen are NSAIDs, analgesics with anti-inflammatory properties. Acetaminophen is not classed as an NSAID, because there is practically no anti-inflammatory effect.

Ibuprofen gives the least side effects at low doses. It has slight anti-coagulating properties, meaning it thins the blood slightly. Its bioavailability ranges from 49-73%, meaning this amount is not neutralised by your body before it can become effective. Of this amount, about 99% is effective. It is metabolised by the liver.

Aspirin has stronger anti-coagulation properties, but can cause stomach problems. It is absorbed completely, and is also metabolised by the liver. It is easier to overdose on aspirin, and chronic overdosage can lead to mortality rates of 25%. It has been associated with Reye's Sundrome in children.

Acetaminophen is metabolised in the liver as well, but at high doses, the body can't handle it and it is metabolised into toxic substances. This is a prime example of bioactivation, where the products are toxic, but the initial molecule is not. It has less side effects than NSAIDs.