Posted by pinksharkmark (216.209.183.37) on June 16, 2001 at 08:14:11:
In Reply to: Imitrex, how old is too old? posted by Van on June 15, 2001 at 21:03:13:
Medications are dated conservatively. If a date says May 2000, it should really read May 2001.
The date at which a compound loses an arbitrary percentage of its strength is considered to be the expiration date. I have no idea exactly what that percentage might be. A licensed pharmacist should be able to tell you.
Almost all complex molecules will break down over time under the influence of heat, light, oxidation and humidity. Once a medication passes its expiration date, it doesn't automatically become poisonous, it simply becomes less and less effective, since more and more of the active ingredient has broken down to simpler compounds.
If your Imitrex injectors were stored according to the directions that accompanied them, they should still be 99% as effective as the day they were purchased.
pinky