Explain to me how Mefenamic Acid works on periods - Emma1977 or someone else!

[nobaby]

Posted a couple of weeks ago about painful heavy periods and being prescribed mefenamic acid to control the pain after coming off the pill (due to migraines). Firstly sorry if TMI at any point!

Anyway I am somewhat confused (and pleased maybe) following my period. I know this drug is supposed to help with the pain, but can also make bleeding lighter... What I want to know is how?! I have a biology background so want to know details! I dont know whether the 'light' period I have just had is a result of the mef acid or was just because my body hasnt yet adjusted to coming off the pill (a month ago). My natural periods used to be extremely heavy and last for 8-10 days (5 very heavy days then the rest 'normal'). I have tried coming off the pill before and these horrendous periods still existed.

So this time round I was prepared! Thursday evening I had a bad headache so took iboprofen (didnt expect period for another week or so) Ten minutes later my period came- heavy. I was told not to take iboprofen with the mefanamic acid so I didnt take any more medication (but was in a lot of pain overnight and period was VERY heavy). Anyway, friday I took 3 doses of the Mefenamic acid as prescribed. Had mild pain, and normalish flow. Saturday, mild pain and virtually no bleeding. Sunday nothing, Monday nothing. Am still waiting for it to come back full flow!

So is this normal? And if so how?! There are no hormones in the mefenamic acid so how does it slow/stop the bleeding? Or do you think this is coincidence and Im just not back to 'normal' yet? I kind of wish I had left it without taking any medication this time to see what happened as now I dont know what it would have been naturally and how much was down to the mefenamic acid. I only took 5 doses in all - is it that powerful?

It's not known, but they think it interferes with prostaglandin synthesis (inhibiting COXs), hence reducing pain. I've not experienced it making bleeding lighter (and when I was at boarding school practically everyone took it, as it wasn't yet prescription-only).

It's not that powerful - taking paracetamol with it may be an idea if it's still painful. Avoiding caffiene can also help with period pains. But a period of a couple days could just be a variation of normal anyway!

Possible TMI - sex just before a period can speed it all up as all the gunk is shifted out faster, so it lasts fewer days...

thanks, so no one knows!? The pain was numbed enough (this time anyway) but I will take paracetamol too next time if its still bad. I dont drink tea or coffee and avoid anything with caffiene anyway as it can give me a migraine. Im just quite at the lightness this time and what happened to the 'gunk' as you put it! Surely it cant just disappear?!

My sister takes this, isn't it also given post operatively, to reduce risk of haemerege?(sp)

It's not a hormonal thing, it is to do with the blood.

nobody knows...

It does slow down the bleeding as well as help with the pain.
I also take tranexamic acid with mefanamic acid. It clots the blood so lessens the flow considerably. Well worth the bother of revisiting GP.

Oh right now i'm in desperate need of some mef acid as i've run ot and in a great deal of pain. Nurofen etc very rarely works for me, certainly not this month anyway. Need to see doc re prescription and soon.

Hi there,

What notcitrus said about the mechanism of action. It is classified as an NSAID (similar chemically to ibuprofen, diclofenac, etc) and they all have the same mechanism of action. However, Mefenamic seems unique in also somehow inhibiting menstrual flow. Nobody knows why it happens, but it is a recognised and recommended treatment for menorrhagia (heavy periods).

I'm glad you've got some relief from it.

I wouldn't class it as particularly powerful, but it seems to either really help or do nothing at all.

Thanks everyone, no wander I couldnt find an explanation for how it works online for inhibiting flow. I dont know that it would control the pain if it was as severe as it used to be (but I dont know if it would have been as severe as it used to be had I not taken it if that makes sense!?)

I guess I will just have to wait until this time next month to see if I get the same again or am back to the hell of my former periods..

Here in the states there is a drug called Ponstel that is a mefenamic acid. While it does everything you want it to it does have risks...such as cardiovascular risks and gastrointestinal risks.
Please please discuss this with your doctor. I know so many people ( and now it seems so many drugs out there) that take something that the risks outweigh the good.

The risks do worry me, this is partly why I am trying to find out more about the drug. I have been prescribed mef acid by my GP after discussing my problem with her. I came off the pill because the risks to me had become too high and felt a lot better for it. But I need something to help with this pain...

As it is similar to iboprofen, does mef acid have the same effect on digestive system? I had problems when I was 14, sort of sore upper stomach..?! after taking iboprofen regularly to help with period pain...

It can have the same effects on the digestive system, but you'd really have to try it and see. I think that's why they made it prescription-only. But on the other hand you could probably take less of it than you were of ibuprofen, so side-effects less likely.

How much are you taking? I think 2x250ug (two of the blue+yellow capsules) is the standard dose, thrice daily, but there's also large yellow tablets (400ug?) which I ended up taking (again 2, thrice daily).

My quick Google of "'mefenamic acid' mechanism" and reading various articles implied that the risks are similar to other NSAIDs, ie not very high unless you notice your GI tract is sensitive to NSAIDs - but I'm not a doctor. Well, I've got a doctorate in medical research, but that's a bit different.

nobaby

If your periods are both painful and heavy then I would seek a referral to a gynae as a matter of course.

Mefenamic acid is all very well short term but its no real solution. You need to determine exactly why this is happening in the first place (you should be investigated further by a gynae to see if there are fibroids and or endometriosis present). Both can cause heavy bleeding and in the case of endo, very painful periods.

notcitrus the dose I have been prescribed is 500mg which should be taken 3 times a day.

I know this isnt really a long term solution, it was suggested I try the progesterone only pill but I know that may not control my periods either and they may then be unpredictable. At least at the moment I know (or should) when they will come!

My periods have always been this way since I started when I was 13. Early on, I went through tests at the hospital (ultrasounds etc) to see if there was any abnormalities and they couldnt find anything... They put me on the contraceptive pill at 14 or 15 when they didnt settle down after a year and a half as I was having too much time off school. Im guessing that nothing has changed since I was younger as it hasnt got worse, but not much better either!

Standard dose, then. Like you I was taking days off school and prescribed the pill. In combination with the pill it was an OK long term solution for me for about 13 years - I tried stopping a few times to see if it had got better, but it hadn't.

Ironically when I stopped most recently to try to get pregnant, I ended up with no periods and seeing a gynae - but again while they thought I had very mild PCOS, nothing to explain it. Maybe being that much older helped; maybe it's true that people who fear periods when they start them have more painful ones and having psychotherapy happened to improve that as well as so much else?

So I agree with Attila that seeing a gynae would be a good idea, but assuming nothing is found, I know of no reason not to keep with the Ponstan, just like there's no usual reason not to take paracetamol every time you have a headache.

Hi nobaby

Re your comment:-

"My periods have always been this way since I started when I was 13. Early on, I went through tests at the hospital (ultrasounds etc) to see if there was any abnormalities and they couldnt find anything... They put me on the contraceptive pill at 14 or 15 when they didnt settle down after a year and a half as I was having too much time off school. Im guessing that nothing has changed since I was younger as it hasnt got worse, but not much better either!"

I can so relate to this. My periods were also extremely painful from the age of 14 when I started menstruating and no-one knew why. Well until I got to 31 years of age that is.....

I was diagnosed with endometriosis - this was the cause of all that pain. I've had surgery for it and saw the photos of my uterus (these photos were used for training purposes!) with the endo all over it.

Endometriosis is NOT detected on ultrasound scans; I am not therefore surprosed that an ultrasound scan revealed anything untoward.

There is much ignorance still out there about endometriosis - you need to find a gynae with up to date knowledge. I had a GP tell me that endo is not a common condition - infact it is the second most common gyanecological problem seen in women after fibroids.

Not knocking the mefanemic acid per se but you need to find out why this is happening.
The pill and these tablets dampens everything down and thus masks the symptoms. It does not take the problem away entirely.

Would urge you to speak with a gynae and keep asking questions - find that many GPs are next to useless when it comes to dealing with such problems.

Do not be fobbed off!!.

Hi Attila! I think I will try and get it investigated further, but when I was on the pill it was so under control, surely there would have been some indication i wasnt normal then?

I am 23 and have been on the contraceptive pill as I said since I was 14 or 15 so I dont really know what my natural periods would be like. I tried a few years ago to come off it but was in agony so went straight back on, but as someone mentioned just aging a bit might make a difference. I have not got any children yet (sorry hijack of mumsnet!) but I desperately do want children later on. I worry about trying to conceive, pregnancy and birth and how painful that is likely to be... do women who have painful periods usually get worse pain?

Having said all this, the period I have just had(as mentioned in OP) wasnt that 'bad'. I think next month I will go cold turkey and see how it is with no medication...so watch out for me moaning about the pain on here! But after that I will look into getting it investigated as I know the medical profession in general are crap with womens health!

if you ar trying for kids can u still take mefenamic acid