[rustyhancock]

You're partially right compared to placebo only about 5% of people are painfree over the effect of a placebo when taking paracetamol.

Paracetamol got it's start as replacing the more effective but much more dangerous and withdrawn drug Phenacetin.

Why don't people notice that it's such a small benefit over nothing? Well because placebo effect is quite good for pain and pain is usually transitory anywhere..if you have a tension headache you're probably going to aim to relax. Turn away from the screen or even have some caffeine and those are more effective than paracetamol!

[freehorse]

Where did you pull this 5% from? There are gazillions of studies showing higher or lower efficacies for different kinds of pain. Along with the inaccuracies about Phenacetin (whose MOA is metabolising into paracetamol).

[rustyhancock]

You will indeed find various figures for various pain types all are far worse than ibuprofen.

Here is an example from the Cochrane library

> For the IHS preferred outcome of being pain free at two hours the NNT for paracetamol 1000 mg compared with placebo was 22 (95% confidence interval (CI) 15 to 40) in eight studies (5890 participants; high quality evidence), with no significant difference from placebo at one hour.

A NNT of 22 means that in absolute terms 1/22 people met the positive endpoint criteria more than placebo. This figure is usually quoted as 20% for placebo and 25% for paracetamol giving NNT of 20.

The NNT of 22 gives 1/22= 4.5%.

https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD...

[emj]

"pain free" is a long way from the pain is manageable. Pain is an understudied subject, where we have too little knowledge. Just using the word manageable is an indication of this.

[rustyhancock]

That's very true, but the metric is applied to all medications you compare against that's what's important. You also just get a baseline idea of what's good by guessing what you'd accept.

Episodic tension type headache tested with ibuprofen Vs placebo NNT is 14. (Btw that's not great itself) But it's better than paracetamols often quoted figure 20.

Here's why I say it's not great. Why don't you guess some reasonable NNTs for say moderate depression treated with SSRIs, or no relapse in schizophrenia treated with an antipsychotic. Now guess the NNT for a statin to prevent a first heart attack.

SSRI for moderate depression about 10, antipsychotics to prevent schizophrenia relapse over 2 years NNT= 3 (excellent )Statin to prevent a first heart attack 200! (This one always shocks me). Statins have a clear role of course.

[0] https://thennt.com/nnt/ibuprofen-treatment-episodic-tension-...

[emj]

Good answer from you part, but I am not qualified to write an response. Pain is temporary for most of us, what we mostly need is something that is slightly better than placebo. I will stick to my "it is probably more complex" I will not make a decision.