Dose vs Manufacturer -- Why does the lower dose work better?

I have Sleep Apnea and control it with CPAP therapy.

I've been taking 50mg Nuvigil daily for years for daytime sleepiness. (It's almost nothing -- the usual starting dose is 150mg.)

I'm wondering why two 50mg pills is way more effective than a single 150mg pill. They're made by different labs in India. What do you think it's due to?

1. The 50mg pills are produced by a "better" lab. (My theory)
2. The optimum dose for me at this time really is 100mg, and side effects from the higher dose are outweighing the benefits. (Pharmacist's theory)
3. Other

I haven't spoken to the doctor yet -- I wanted to give the 150mg dose more time. Here's more background...

At my latest office visit, I complained about fatigue and brain fog, so the doctor suggested increasing the dose. The pills come in 50, 150, 200+, so we collectively agreed to go right up to 150 without titrating.

I still had several pills of the 50mg left, so I started taking two at once at the usual time. I was impressed by how effective it was! This lasted for a few days, until I ran out and switched to the 150mg pills.

The triple dose was much less effective than the double dose.

Hi @SquarePegGuy that is interesting. I am not familiar with that med but I have experienced that a small dose of Mirtzapine induces sleep much better than a 30 mg dose. This was recommended by the prescriber.

I think buying overseas meds has a risk that they may not be the dosage on the label. Try US made meds if your pharmacy has them.

Also you might tell the different symptoms of the higher dose and ask your prescriber if you can try a lower dosage, but the one site I checked says the recommended adult dose is 150 MG.

Different manufacturers can use different non medicinal ingredients in their formulary. I know a woman who is really sensitive to meds. She takes an antidepressant that's available as a generic. The pill from one pharmacy works great for her, but when they discontinued manufacturing she found that none of the pills from the other manufacturers worked for her.

Also sometimes people react differently to lower vs higher doses of meds. For example I find 25 mg of Seroquel much more sedating than 200 mg, which makes no sense to me, but that's what it is for me.

Same thing for me with Seroquel, but it is a known fact about Seroquel: it is used as a sleep med in low doses (even in non-psych patients) and in high doses as a full-force mood stabilizer.

I have no new theory, SPG, but I will be curious to learn what you ultimately conclude the cause is.

I would've initially thought #2 because I know it can work that way with certain meds (I know the benzos and stimulants that I've tried specifically are like that for me), but I've had some scenarios with some meds (Ativan comes to mind) where I'll take 2mg of brand x and 2mg of brand y and have totally different reactions so #1 is a valid speculation as well.

There's also the "placebo/psychological" effect idea where maybe you think taking 2 pills is going to be more effective and therefore it is?? Possibly. Just throwing that as an idea out there. I might do that with antipsychotics (or they all just DO make me irritable and Rexulti DOES really make me compulsively chew myself...) (well, it does, but is that because that's a side effect or because I think it will so it does?)

Thank you, all, for these comments.

I found I was able to cut the pills into a 2/3 piece and a 1/3 piece (approximately). I'd been taking the 2/3 piece (or two 1/3 pieces) for ovre a week. This still didn't provide the same response as the two 50mg pills.

Then I started working a third explanation this morning -- oral absorption. The 50mg pills would partially dissolve in my mouth before I could swallow them. But the new 150mg pills have a smooth coating; they go down without a hitch.

The 50mg pills do not have a coating. They remind me of the old-fashioned aspirin tablets (before enteric coatings became popular). The pill(s) would get stuck to my tongue. (I take all five pills at once.) I'd swallow all the other pills, but then have to take more water to swallow the 50mg Nuvigil.

So this morning I held the 2/3 pill in my mouth until I started to taste it. Only then I swallowed it. It's only the first day of trying this, but I seemed a little more alert after that, even though I was extra groggy. I think "oral absorption" might explain the effects.