# What Happens If You Take A Nitroglycerin Tablet Without Needing It? **URL:** \ **Category:** Factual Questions\ **Created:** [June 11, 2011, 4:00am UTC](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074 "2011-06-11T04:00:32Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [June 11, 2011, 10:06pm UTC](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074/21 "2011-06-11T22:06:24Z")
> [@KlondikeGeoff](#): > > Wow, that takes me back. I was a chemistry freak, and had a pretty good lab even before I took Chemistry in HS. I loved to make nitro tri-iodide, pouring it on a piece of filter paper to dry. Made a nice loud noise when hit, alright. As a public safety message I want to point out that stuff is both extremely unstable and extremely powerful. You’ve been warned. ---
**Author:** ![Andy](https://avatars.discourse-cdn.com/v4/letter/a/aeb1de/32.png) [@Andy](https://boards.straightdope.com/u/Andy)\ **Post date:** [June 11, 2011, 10:09pm UTC](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074/22 "2011-06-11T22:09:53Z")
Nitroglycerine is just a prodrug in this situation; the active compound is nitric oxide, NO, which has got to be the simplest/lowest molecular weight biologically active compound out there. Hydrazoic acid, HN3, is also a potent vasodilator. It gives an appallingly intense, albeit short lived, headache. ---
**Author:** ![Pai325](https://avatars.discourse-cdn.com/v4/letter/p/c68b51/32.png) [@Pai325](https://boards.straightdope.com/u/Pai325)\ **Post date:** [June 11, 2011, 10:57pm UTC](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074/23 "2011-06-11T22:57:22Z")
They gave me a nitroglycerine tablet in the ER when they were trying to figure out if I was having a heart attack. I don’t remember anything happening, but that might have been because I was in so much pain. It was not heart; it was my first (and last) gall bladder attack. I had it out the next week. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [June 12, 2011, 6:58am UTC](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074/24 "2011-06-12T06:58:17Z")
> [@Crescend](#): > > It has a whole bunch of effects. It prevents the formation of vasoconstrictive factors (like thromboxanes), but it also prevents the formation of vasodilatory factors (like prostacyclins). There’s some cross-talk with other pathways like bradykinins. Overall, many of those effects are a wash, and its main effects are analgesic, anti-inflammatory, and anti-platelet aggregation - which is what it’s prescribed for. The trick is that the enzyme that aspirin inhibits is found in multiple places in the body, but most of those places can make more of it after aspirin knocks it out; the places that can’t regenerate the enzyme (i.e., platelets) largely determine the overall effect. > > Interestingly, because similar factors also have an effect on bronchoconstriction/dilation, there are some variants of asthma that are sensitive to aspirin - in those cases, taking aspirin will prevent the formation of bronchodilatory factors, causing an asthma attack. It’s not common, though. Which of these effects cure headaches? ---
**Author:** ![Khan](https://avatars.discourse-cdn.com/v4/letter/k/3ab097/32.png) [@Khan](https://boards.straightdope.com/u/Khan)\ **Post date:** [June 12, 2011, 4:44pm UTC](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074/25 "2011-06-12T16:44:11Z")
> [@KarlGauss](#): > > Pardon my nitpickiness, but all other things being equal, anything that drops your blood pressure will lead to a compensatory _increase_ in heart rate. > > … > > NTG prevents/relieves angina by both dilating arteries in the heart itself (thereby bringing more oxygen to the heart) and by causing blood to pool in the veins of the body. Such pooling means that there will be less blood delivered back to the heart which means, in turn, that the heart muscle isn’t strained as much (and thus can get by with less oxygen than when not experiencing that NTG effect). You’re right about the decreased O2 demand and the effect of decreased blood pressure on heart rate. Giving a little nitro can decrease O2 demand, but too much can have systemic effects that drop blood pressure and make the heart beat faster, thereby actually INCREASING the strain. What’s tricky is that the tipping point where you go from decreased O2 demand to reflex tachycardia can vary a lot from person to person and is very difficult to predict. With someone who has nitro pills for angina, the goal is pain relief. Less pain is more calm, more calm is less stress on the heart while you wait for the ambulance to pick you up and take you to the hospital for an EKG, blood tests, and maybe a trip to the cath lab to get a stent put in. Someone else takes it who doesn’t need it? Yeah, headache and maybe dizziness upon standing. That’s what you get for taking grandpa’s medicine, ingrate. 😉 ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [June 12, 2011, 10:48pm UTC](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074/26 "2011-06-12T22:48:46Z")
> [@AaronX](#): > > Which of these effects cure headaches? Short answer: the reduced proglastandins, as proglastandins are not only inflammatory but also transmit pain. Longer answer: Aspirin’s primary mode of action is to stop the production of the COX enzymes. COX-1 is used to create thromboxanes, while COX-2 is used to create proglastandins. But it doesn’t just block COX-2, it also modifies it so tjat, instead of producing proglastandins, it also produces lipoxins, which are anti-inflammatory. The lack of proglastandins reduce the transmission of pain, but, due to the opposite effect of the lack of thromboxanes, are not that anti-inflammatory. But the lipoxins make up for this. Both reduction in pain transmission and anti-inflammatory actions help to reduce headaches. ---
**Author:** ![Rysdad](https://avatars.discourse-cdn.com/v4/letter/r/7cd45c/32.png) [@Rysdad](https://boards.straightdope.com/u/Rysdad)\ **Post date:** [June 13, 2011, 1:36am UTC](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074/27 "2011-06-13T01:36:08Z")
> [@Markxxx](#): > > So everyone gets headaches? Even the cardiac patients? I guess it’s better than dying 🙂 I had bronchitis, and I went to the emergency room. I made the mistake of saving that it hurts ::here:: while pointing to my chest. Among other things they did was to give me a nitro pill. They said it would give me a bad headache. It didn’t. Still, to this day, I can say that I’ve never, ever had a headache. So, in answer to your question…no. [Previous page](https://boards.straightdope.com/t/what-happens-if-you-take-a-nitroglycerin-tablet-without-needing-it/585074.md?page=1)