sdyer@bbncca.ARPA (Steve Dyer) (12/10/84)
The active ingredient in Midol is plain old aspirin, along with something
which is claimed to be an anti-spasmodic/muscle relaxant--cinnamedrine, an
obscure drug which is related to ephedrine, a mild stimulant/decongestant.
Cinnemadrine may have some relaxant effect on the uterus; it's interesting
that another sympathetic amine, ritodrine, was recently approved by the FDA
for treatment of premature labor. I wonder if Mike's testimonial for Midol
for headaches may result from any "feel-good" stimulant effects it might
have! :-)
Menstrual cramps have been traced to excessive levels of prostaglandins
produced during the cycle. Strangely, both aspirin and ibuprofen work by
inhibiting prostaglandin synthesis, but aspirin is MUCH less effective than
ibuprofen or similar drugs when treating women with menstrual cramps-- no
one knows why. Many women would swallow entire bottles of aspirin over the
time of an attack, and not get the relief that 400mg of ibuprofen provides.
--
/Steve Dyer
{decvax,linus,ima,ihnp4}!bbncca!sdyer
sdyer@bbncca.ARPAgoadsby@rocky2.UUCP (Peter Goadsby) (12/22/84)
The difference in actions of 'cinnamedrine' and 'ritodrine' is related to there different agonist profiles. The former having greater alpha-1 agonist activity, and the latter having greater beta-2 agonist properties. The use of beta-2 agonists to delay labour is a well established O&G indication in other countries.