Timing of medication consumption

Note: I am not asking for medical advice, any concerns I have about my medication I intend to discuss with my doctor at my next appointment.

So, onto the question. I was recenty prescribed Topamax 25mg as a mood stabilizer. My doctor instructed I take it at dinner then at bedtime, because of its tendency to cause drowsiness. I, however, haven’t noticed any drowsiness.

Now, she also instructed me to start off with 1 pill a day for a week, then increase it to 2, and we’ll see about any necessary dosage increases at my next appointment. She didn’t tell me whether I should take the 1 pill at dinner or bedtime- I’ve been taking it at dinner. My question is- is taking it at a particular time of day better for keeping a higher dose of it in my system when it’s really needed? I mean, if I take it at dinner, by the time it’s been broken down and all gotten into my bloodstream, I will be ready for bed shortly thereafter, and spend 8 hours with it at its highest efficacy (I assume) while I’m sleeping.

For certain medications, this doesn’t matter, but for something like a mood stabilizer, I’m not sure. I don’t know if it takes a while to build up in your system, as antidepressants do (it doesn’t seem like it- the literature I’ve read indicated some patients begin to feel its effects the first week).

I know that my niece takes Ritalin for ADHD and by 7 or 8 PM she’s a terror because the Ritalin has effectively “worn off.” I also remember when I was a teenager, I was taking Wellbutrin and my doctor recommended switching to taking one of them at bedtime so I would feel better when I woke up instead of waiting for it to kick in- it worked very well, my friends at school wondered why I was so cheerful in the mornings all of a sudden.

Any doctors or pharmacists care to weigh in on the most effective timing of taking certain medications?

When I had a similar question about a medication I asked my pharmacist who seemed to be able to call up the half-life of the medication on his database with no problem. If your pharmacist has the same capability, you could call and ask.

>is taking it at a particular time of day better for keeping a higher dose of it in my system when it’s really needed?

This is one of a variety of reasons for taking it at a particular time. As an example of another reason, Prednisone, a stearoid, should be taken early in the morning because the body makes its own version of that stearoid, and measures its levels during the hours before normally arising in order to decide how much to make. If you took the drug shortly before then, for example just before going to bed, the body would back way off its own manufacture to compensate, and the drug would have less effect on what it is supposed to fix and more effect on your own endocrine system regulating itself.

I take my antidepressant (Amitriptyline HCl) in the evening, because I also suffer from severe insomnia, and it works better than any dedicated sleeping pill I’ve tried. Actually, it works much better as a sleeping aid than as an antidepressant.

From Wikipedia: “In order to avoid early side-effects (e.g. cognitive dysfunction) the initial dose normally is low and increased in slow steps. The usual initial dose is 25 to 50 mg daily in 2 single doses. Recommended increments are 25 to 50mg every 1 or 2 weeks. Common doses for maintenance treatment are 100 to 200 mg daily. The highest dose possible is 1,000 mg daily in divided doses.”

Also from that site, the half life of Topamax is 19-23hrs. For most medications, it takes 4-5 half-lives to reach a steady state. In other words 76-115hrs to reach a steady state of plasma concentrations. This is variable depending on your other medications, your personal metabolic rate, your liver and kidney function, etc. For a medication that is once-a-day like Topamax, it usually doesn’t matter what time of day you take it as far as your desired effects, but it can make a difference for your side effects.

Interesting. I didn’t realize the slow increase in dosage of medications was meant to minimize side effects- I always assumed it was to find the lowest effective dose for your body so that you weren’t ingesting more than necessary.

Speaking of side effects- I haven’t noticed any of the bad ones, like drowsiness or cognitive dysfunction, but I did notice a change in the taste of carbinated beverages. I had a Coke tonight, it tasted so weird.