cellio: (lilac)
[personal profile] cellio
I'm allergic to Pennsic. (Well, to dust and grass and pollen and weeds and...) So I take Allegra for about three weeks each year to deal with that, but don't take it the rest of the year. (I don't want to develop a resistance to it like I did to all previous allergy drugs save one [1].)

This year I started taking it on Saturday, and then went to Cooper's Lake Sunday for setup. I was fine yesterday, but today I've been congested all day. Mid-day I added Sudafed to the mix; I hope that wasn't bad but I really needed to treat the symptoms. (I take the Allegra once a day and had taken it this morning.) It took about four hours for the Sudafed to produce results.

I think this must have happened in the past, because there's Sudafed in with my use-only-at-Pennsic stuff. Now that I think about it, I remember once calling my doctor from Pennsic to ask if taking Sudafed while taking Allegra would kill me and he said it wouldn't.

I don't know if starting the Allegra earlier would help; how long does it have to be coursing through your veins to lay down a basic barrier against the nasty little allergens? With luck, writing this entry will help me remember next year to start earlier. (I'm sort of assuming that I should be taking allergy drugs (Allegra) and not cold drugs (Sudafed) as a baeline. I don't have a cold; I just have some of the symptoms.)

I should remember to ask my doctor if he can improve on this for me.

[1] Seldane. It worked gloriously, better than Allegra I think, so naturally the FDA eventually decided I couldn't have it.

(no subject)

Date: 2005-08-08 10:20 pm (UTC)
kayre: (Default)
From: [personal profile] kayre
You can buy Allegra-D, which is allegra plus sudafed, so adding the sudafed is absolutely fine.

Allegra is supposed to be very closely related chemically to Seldane, but I also found Seldane more effective.

I'm not sure how long it would take to be effective, but I'd try at least 3 days ahead, personally.

(no subject)

Date: 2005-08-08 10:58 pm (UTC)
geekosaur: orange tabby with head canted 90 degrees, giving impression of "maybe it'll make more sense if I look at it this way?" (Default)
From: [personal profile] geekosaur
I recall their recommmending taking it 1-2 weeks ahead, since the time it takes to reach full potency varies. (Of course, they'd also like you to take — and pay for — more of it....)

I also seem to recall that Allegra and Seldane both are metabolized into the same actual antihistamine, but Allegra is less effectively metabolized. (Whereas Seldane is simultaneously metabolized via another pathway to something that causes heart attacks (or was it strokes?) in some percentage of people, or something like that.) I didn't pay too much attention, since it turned out that I don't even digest it. (Oy. On the other hand, it also turned out that antihistamines don't help me, so it's all irrelevant.)

(no subject)

Date: 2005-08-09 12:27 am (UTC)
From: [identity profile] sethcohen.livejournal.com
As a result of the drug-drug interactions Seldane and Hismanal exhibited, there was serious research done into what drugs also cause Q-T prolongation. Neither Seldane or Hismanal alone were risky if taken alone, but people rarely take just one pharmaceutical product...so the drugs came off the market.

(no subject)

Date: 2005-08-09 12:25 am (UTC)
From: [identity profile] sethcohen.livejournal.com
Allegra is what Seldane is metabolized into. There are drug-drug interactions that cause Q-T prolongation (a kind of heart arrythmia) that is bad enough in some people that it can kill them. This only happens with Seldane, not Allegra.

(no subject)

Date: 2005-08-09 12:35 am (UTC)
From: (Anonymous)
how long does it have to be coursing through your veins to lay down a basic barrier against the nasty little allergens?

About an hour. Peak blood serum concentrations are reached (on average) in 2.6 hours. FYI, the laws of steady-state metabolism means that it takes about 5 half-lives for steady-state to be reached. I recall that you've taken enough math to know what I mean, but I don't remember if you remember the math in question. In general, if the drug is supposed to last 12 hours and you take it every 12 hours, it'll take (5x12, or 60) hours for you to reach the maximum amount in your body, and thus maximum effectiveness. It works in reverse as well. If you were at maximum blood levels, and you stopped taking it, it'll all be out of your body in the same amount of time.

Be lucky that antihistamines aren't as bad as amiodarone. Amiodarone has a 51-day half-life.

D'oh!

Date: 2005-08-09 12:36 am (UTC)
From: [identity profile] sethcohen.livejournal.com
Of course, that was me. I'm responding from Karen's computer, which can be placed under a fan or air conditioning (or, in this case, both). I'm warm.

(no subject)

Date: 2005-08-09 10:18 am (UTC)
From: [identity profile] sethcohen.livejournal.com
Whoa...remember that it's still 5 half-lives. If the drugs lasts for 24 hours, then you need to take it for 5x24 hours, or 5 days to reach maximum potency.

Amiodarone is used to treat a kind of heart arrythmia. :)

(no subject)

Date: 2005-08-09 05:31 pm (UTC)
From: [identity profile] jerusha.livejournal.com
According to my pocket reference, the elimination half-life of fexofenadine (the active ingredient in Allegra) is 14.4 hrs. So you would need to start your dosing 72 hours in advance of exposure. So if you'll be on site Sunday, you should start taking it on Wednesday night or Thursday morning.

(no subject)

Date: 2005-08-09 06:50 pm (UTC)
From: [identity profile] sethcohen.livejournal.com
As your allergies are situational, I'd recommend taking it in the morning. It takes a bit for your immune system to respond to the pollen insult, so the antihistamine will already be in your blood by the time it's thinking about responding. If you had allergies related to being home (e.g. dust mite allergy) I'd recommend you take the Allegra in the afternoon or evening.

(no subject)

Date: 2005-08-09 03:48 am (UTC)
From: [identity profile] sekhmets-song.livejournal.com
Funny how different people react differently to the same drug: Seldane didn't do crap for me. I suspect I'd have the same issue with Allegra. I'm a Clariton girl (though I only take it one or two days a week in the summer. The winter is when I need it daily), now.
I remember when they pulled Seldane from the market. I still had half a bottle left (and something like 4 months left on the prescription) and had friends begging for my leftovers when theirs ran out.

(no subject)

Date: 2005-08-09 04:35 am (UTC)
From: [identity profile] dagonell.livejournal.com
If I could figure out how the quirk in my brain functioned, I would be revered throughout Pennsic... For the longest time, David suffered from hayfever while Dagonell did not. Yes, you're reading that correctly! My mundane modern identity had a prescription for hayfever which my medieval persona never needed. Camping with the family? Bring the tissues and meds. Pennsic? No problem! Nowadays, I'm more fortunate. It has to be a *very* heavy pollen day before I'm affected.

Weirdly enough, the effect is not undocumented. Sybil, the famous multiple personality, had it. Several of her personas had allergies that other personas didn't have. It's apparently a mental trick, but I don't know how I did it.
-- Dagonell

(no subject)

Date: 2005-08-10 10:19 pm (UTC)
From: [identity profile] alfiechat.livejournal.com
Loved taking Seldane. I beleive i used to take seldane D. Allegra didn't work as well. Now i take Zyrtec D and it works much better than allegra ever did.

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