what are the medications that have to be taken on an empty stomach?

February 10, 2023 5:33 PM

I am asking that because I think most medications have to be taken with food. And I As an aside, how does one measure empty stomach? How long should it be since you've eaten? Or do you have to feel hungry? P.S I put it in "health and fitness" category, but I'm wondering if it would be better in "science and nature".
posted by amfgf to Health & Fitness (18 answers total)

Best answer: Levothyroxine does, and you're not supposed to eat for awhile afterwards either. Most people who need thyroid hormone supplementation take it first thing after they wake up.
posted by potrzebie at 5:35 PM on February 10, 2023 [8 favorites]

Best answer: And in general if a medication is meant to be taken on an empty stomach your doctor will give you some guidelines on what that means. In my experience it's either "first thing in the morning" as above, or 4+ hours after the last time you ate anything.
posted by potrzebie at 5:37 PM on February 10, 2023

Best answer: And to add to potrzebie's answer, the reason you need to take that medication on an empty stomach is because food changes how the medication is absorbed to your body. It may prevent the medication from working correctly.
posted by meowzilla at 5:40 PM on February 10, 2023

Best answer: Thank you potrzebie, and meowzilla. I googled for a list of medications that need an empty stomach.
posted by amfgf at 5:56 PM on February 10, 2023

Best answer: Tylenol acts a bit faster on an empty stomach.
posted by 922257033c4a0f3cecdbd819a46d626999d1af4a at 7:13 PM on February 10, 2023

Best answer: When I was taking Doxycycline for malaria prophylaxis I was told to take it on an empty stomach. Which was miserable -- it made me nauseous every morning on that vacation.

The next time I was prescribed it, the doctor told me to go ahead and eat something.

Your question made me curious as to why, and I found a short article "effect of food on doxycline absorption" . The introduction may have some good search terms for you if you want to dig deeper.
posted by Metasyntactic at 8:27 PM on February 10, 2023

Best answer: Omeprazole and derivatives are usually advised at least a few hours after food (or first thing in the morning) and 20-30 minutes before your next meal. Try explaining that to a hungry cat...
posted by I claim sanctuary at 9:16 PM on February 10, 2023 [2 favorites]

Best answer: With levothyroxine sodium, the advice often seems to be to take first thing in the morning and wait 30 - 60 minutes before food, coffee etc. But it apparently absorbs over three hours, so even waiting 60 minutes is not ideal.

I switched to taking it before bed instead. I wait two hours after eating, but I suspect the advice is probably to wait longer than that. It sucks.
posted by kinddieserzeit at 9:44 PM on February 10, 2023 [1 favorite]

Best answer: Klonopin and presumably other benzos have no warning either way but taking them with food will slow down how fast it's absorbed so presumably you want to take it on an empty stomach for effectiveness.
posted by fiercekitten at 10:21 PM on February 10, 2023

Best answer: My cat was on Denamarin for years for his liver, and it's supposed to be taken on an empty stomach. For cats that's one hour before eating or two hours after.
posted by Violet Hour at 11:21 PM on February 10, 2023

Best answer: I take micronised progesterone, and that needs to be taken on an empty stomach, which the packet states means 2 hours after food or half an hour before food. It also has a mildly sedative effect so I take it at bedtime.
posted by altolinguistic at 12:08 AM on February 11, 2023

Best answer: The oral typhoid vaccine is supposed to be taken on an empty stomach; I think the bottle said take it first thing in the morning and then wait an hour before eating.
posted by Ms Vegetable at 6:30 AM on February 11, 2023

Best answer: Rybelsus (oral semaglutide for t2 diabetes) is supposed to be taken on an empty stomach first thing in the morning with a minimal amount of water, and then you’re supposed to wait an additional 30 min before eating. The instructions are very specific.
posted by maleficent at 6:32 AM on February 11, 2023

Best answer: Ambien is supposed to be taken on an empty stomach.
posted by lhauser at 11:02 AM on February 11, 2023

Best answer: My blood pressure medicine needs to be taken on an empty stomach. A buddy who used to be a pharmacy technician told me that means two hours after eating something. I take some other medication that can be taken with food or on an empty stomach. So I think it really truly no kidding depends on the specific medication. Yesterday I was researching my meds by searching for the name of the medication with “best time to take” because I suspected I was taking some at times that were not optimal.
posted by Bella Donna at 1:24 PM on February 11, 2023

Best answer: My physician suggested I take my levothyroxine when I wake up in the night to pee, which I do every night without fail. She's a genius.

Alendronate sodium (generic for Fosamax) has to be taken on an empty stomach, and 30 minutes to an hour before eating.
posted by Dolley at 5:06 PM on February 11, 2023 [1 favorite]

Best answer: how does one measure empty stomach? How long should it be since you've eaten?

This can sometimes get tricky. Got accused of being noncompliant because my blood tests showed such uneven levels of what a med I was taking was affecting, from month to month. But I knew I was taken my pills very regularly in the middle of the night, when I invariably woke up for no good reason, about as far from mealtimes as I could get. Turns out, they weren't considering that a person with slow digestion (e.g., gastroparesis) might not ever have an empty stomach.

Sometimes meds can be given in different formulations to get around this.
posted by to wound the autumnal city at 9:36 PM on February 11, 2023 [1 favorite]

Response by poster: Thank you everyone.

I find all the answers (on all my questions) useful. I find it impossible to chose just one or two or three, as best answers. Some are detailed and helpful, some are brief and helpful. So, I give everyone best answers, and then later one I give to all the favorite.
posted by amfgf at 2:59 PM on February 14, 2023 [1 favorite]