How do "extended release" medications work?

[merrilinda]

I recently had a bad reaction to Tussionex Suspension and had to go to the ER.  I agree with the doctor that I had a reaction to the Tussionex, but I'm wondering why it affected me so long after I initially took it (I didn't have any symptoms for the first 7-8 hours).

I apologize if this is in the wrong forum, but I thought a pharmacist would be the best one to answer my question.

How do extended release medications work? (In this instance a suspension)  Could it be possible that I didn't shake the bottle up well enough and got too much of the "extended release" part of the medication and not enough of the "immediate release" part?  Are there 2 types of the medication in the suspension? Or is it made in such a way that it's all absorbed at once and just metabolizes more slowly (so it lasts a longer time)?  

I'm just confused about how this medication works, and trying to understand the side effects/symptoms that I experienced in relation to how the medicine works.

[Jennifer R, RPh]

Glad it helped.

Jennifer R RPh www.drugstore.com

[merrilinda]

Thank you! I've already made an appointment with my PCP to discuss the whole thing, but I was hoping that by figuring out how the medications work I might find where I did something wrong.  I know that my Adderall XR works by having some lightly coated "beads" that are absorbed quickly, and some heavier coated "beads" that are absorbed later.......so I was thinking there may have been a similar system with the Tussionex.  I kept thinking maybe I didn't shake up the bottle well enough and got an uneven amount of the "extended release" part of the medication.  If that's the case then what happened was caused by me and isn't anything to see my doctor about.

But what you've told me helps tremendously and lets me know that I've made the right decision to go see my doctor, that something else is possibly wrong that caused my reaction.  Thank you VERY much! :)

[Jennifer R, RPh]

I apologize that I cannot offer more to you than a description of how Tussionex works. I am not a doctor so I can diagnose you or evaluate why you may have had the reaction that you did that forced you to go to the ER. I would urge you to make an appointment with your primary prescriber to have him or her evaluate you as there truly is no substitute for a doctor's visit and physical exam.

With that said, this is the information I can offer you regarding Tussionex.
Chlorpheniramine maleate and hydrocodone bitartrate are used together in an oral preparation to relieve coughing and upper respiratory symptoms associated with allergic rhinitis or the common cold. Hydrocodone release from the Tussionex® oral suspension is controlled by the Pennkinetic® system. Chlorpheniramine release from Tussionex® is prolonged by use of an ion-exchange polymer system.

Chlorpheniramine is well absorbed from the GI tract. The onset of action of chlorpheniramine is about 30—60 minutes, with peak concentrations occurring in about 2-6 hours and peak effect in about 6 hours. The duration of action is between 4—8 hours.

Hydrocodone is well absorbed from the GI tract. Onset of analgesic action is achieved in 10—30 minutes. Peak analgesic effect occurs in 30—60 minutes and lasts for 4—6 hours. Antitussive activity also lasts for 4—6 hours.

Again I would urge you to follow up with your primary care prescriber to discuss your situation. Best of luck to you.

Jennifer R RPh www.drugstore.com