I rate Nitro 8 out of the 33 drugs we carry.
Nitro has two main indications – for cardiac chest pain and for pulmonary edema. It is of minor utility in one, and lifesaving in the other.
I once gave Nitro all the time to any type of chest pain. If they improved, I deduced the chest pain was cardiac, if they didn’t it was plueritic pain. Wrong assumptions. I later read that Nitro as a smooth muscle relaxant is as likely to resolve non-cardiac chest pain as it is cardiac. I also recognized that nitro, other than a wishful thinking effect, quite often had very little effect on patients having obvious STEMIs. It also had a tendency to drop the blood pressure of certain patients.
When I started as a medic no one ever taught us about right-sided MIs. Looking back at old run forms, I dropped the blood pressure in quite a few people having inferior MIs. I thought their heart attack was just making them worse. Preload? What’s preload got to do with it?
On top of all this, studies came out that showed that nitro makes no difference at all in mortality or morbity in patients having MIs.
Here’s some of what the American Heart Association says about Nitro for ACS in the 2005 Guidelines – Stabilization of the Patient With Acute Coronary Syndromes:
The treatment benefits of nitroglycerin are limited, however, and no conclusive evidence has been shown to support routine use of IV, oral, or topical nitrate therapy in patients with AMI. With this in mind, these agents should be carefully considered, especially when low blood pressure precludes the use of other agents shown to be effective in reducing morbidity and mortality (eg, beta-blockers and angiotensin-converting enzyme [ACE] inhibitors).
We were finally taught to use caution in the use of Nitro if the patient is having a right-sided MI. I then routinely did right-sided ECGs until one ED doctor I greatly respect told me he just assumes all inferior MIs are right-sided and just doesn’t give them nitro. The possible danger to the patient’s preload is just too great too risk for no benefit in outcome. With other tasks to be done during a chest pain, while doing a right-sided 12-lead can produce an I’m a smart medic look at me moment, it is of less priority since it doesn’t effect my treatment.
It is amazing to me sometimes how poorly we do spreading knowledge to medics or even doctors. The 2005 AHA guidelines prohibit the use of Nitro in chest pain under the following three conditions (Class III, which means harmful):
1. Patients with hypotension (SBP 30 mm Hg below baseline),
2. Bradycardia (100 bpm)
Less than 90 was always apparent. We use 30 below baseline I had been unfamilar with. I had thought <100 applied to all patients. So if someone started out with a BP of 180, I just kept dropping it down until it hit 100. And I had routinely given Nitro to ACS patients with heart rates above 100.
I brought in a recent inferior MI with a heart rate of 112. The doctor asked me if I had given Nitro. I said "No, he’s tachycardiac, its contraindicated." I could see in the doctor’s eye a little Hmm going on. She did not then order Nitro. I have had other doctors thank me for not giving nitro in inferior MIs.
So, if Nitro was just for chest pain, it would not be in my Essential Eight. It would be pretty far down the list. (I should point out IV Nitro, which we don't carry, has earned more positive recommendations for its use).
Nitro for pulmonary edema, on the other hand, is a different story.
Jems magazine ran a picture a few years ago in a story about CHF that had vials of Lasix and Morphine with the circle with the slash through it sign over the vials. The article said what is being widely taught now that CPAP and Nitro are the front line against CHF, while Lasix and Morphine our on the way out the door completely. Pulmonary edema is frightening call, and I pound the Nitro into my patients, and have seen great results. You don’t stop at 3, but keep giving it every 3-5 minutes as long as their pressure holds. The Nitro with the CPAP is an awesome combo. CPAP doesn’t cure the patient, merely keeps them from crashing until drugs (like Nitro) can be given to stop the event.
We used to carry Nitro paste, but are getting rid of it in favor of continual Nitro under the tongue every 3-5 minutes. Our doctors feel Nitro paste is too unreliable as its absorption varies so widely from patient to patient.
One last point on Nitro. If you have ever struggled to get a patient to lift their tongue up so you can squirt the Nitro underneath, read this: Lingual Nitro. Bottom line — and it was new to me until a reader pointed it out — Nitro Ligual works just fine on top of the tongue.
Class: Vascular smooth muscle relaxant
Action: Systemic vasodilator which decreases myocardial workload and oxygen consumption.
Indication: Angina Pectoris
Children under 12 yrs
Use of Erectile Dysfunction drugs within 48 hours
Side effect: Hypotension, rarely brief asystole,
Headache and facial flushing
Dizziness, decreased LOC
Dose: 0.4mg may repeat q 3-5 minutes, titrate to pain, effect and blood pressure
Route: Sublingual – spray or tablet