nitroglycerin sublingual

Action and Spectrum

Actions and Spectrum:  

The primary action of sublingual nitroglycerin is the release of nitric oxide (NO) in smooth muscle cells of blood vessels. Nitric oxide is a potent vasodilator that induces relaxation of smooth muscles in blood vessel walls. This relaxation results in the widening of blood vessels, allowing for an increased blood flow through them. Consequently, this action reduces the workload on the heart and improves the oxygen supply to the heart muscle, which can relieve chest pain.  

The spectrum of nitroglycerin sublingual is relatively short-acting, with an onset of action of 1-3 minutes and a duration of effect of 20-30 minutes. It is commonly used as a rescue medication for the acute relief of angina attacks. However, repeated dosing of nitroglycerin sublingual may lead to tolerance, which reduces its effectiveness over time. Therefore, it is important to follow the prescribed dosing regimen and consult with a healthcare provider if angina symptoms persist or worsen. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Tachycardia 

Flushing 

Headache 

Nervousness 

Hypotension 

Blurred vision 

Dizziness 

Xerostomia 

Lightheadedness 

N/V 

Xerostomia 

Black Box Warning

Black Box Warning:  

nitroglycerin sublingual tablets possess potent vasodilator properties that may lead to significant hypotension, which could be life-threatening in certain circumstances. Patients must be informed to immediately seek medical attention if they experience symptoms like lightheadedness, dizziness, or fainting after using nitroglycerin sublingual tablets. 

Moreover, nitroglycerin sublingual tablets are not recommended for use in patients with severe anemia, hypotension, or head trauma. It should also be utilized with caution in patients who have a history of congestive heart failure, liver or kidney disease, or hypothyroidism. 

Contraindication / Caution

Contraindication/Caution:   

Allergy: If an individual has an allergy to nitroglycerin or any of its components, they should not use this medication. 

Severe anemia: nitroglycerin can increase blood flow and reduce blood pressure. If you have severe anemia (low red blood cell count), this can exacerbate your condition and cause further problems.  

Glaucoma: nitroglycerin can cause dilation of blood vessels, including those in the eyes, which can worsen glaucoma. If you have glaucoma, nitroglycerin should be used with caution.  

Recent use of erectile dysfunction medication: nitroglycerin should not be used within 24 hours of taking medication for erectile dysfunction, such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra). These medications can also cause a drop in blood pressure, which can be dangerous when combined with nitroglycerin. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology:

The pharmacology of nitroglycerin sublingual is based on its ability to dilate blood vessels, specifically the veins, which results in decreased preload and afterload on the heart. This, in turn, reduces the oxygen demand of the heart, relieving the symptoms of angina. 

Pharmacodynamics: 

The pharmacodynamic mechanism of nitroglycerin involves the production of nitric oxide (NO) in smooth muscle cells. Nitric oxide is a potent vasodilator that relaxes the smooth muscles of blood vessels, leading to an increase in their diameter and a decrease in vascular resistance. This effect results in improved blood flow to the heart and other organs, including the lungs and brain.  

MOA: The mechanism of action of nitroglycerin sublingual is related to its conversion to nitric oxide (NO) within the body. Nitric oxide is a potent vasodilator that relaxes smooth muscle cells in blood vessels, allowing them to widen and increase blood flow. nitroglycerin is metabolized to NO in smooth muscle cells, leading to vasodilation of the veins, which reduces the amount of blood returning to the heart, and hence, the heart’s workload.  

Pharmacokinetics: 

Absorption:  

When nitroglycerin is taken sublingually (under the tongue), it is rapidly absorbed through the mucous membranes of the mouth and into the bloodstream. The onset of action occurs within 1-2 minutes. 

Distribution:  

Once in the bloodstream, nitroglycerin quickly spreads throughout the body. It has a high volume of distribution, which means that it can distribute widely into the tissues.  

Metabolism:  

nitroglycerin is metabolized primarily in the liver by the enzyme glutathione-S-transferase. It is converted to an active metabolite called nitric oxide, which causes the smooth muscle in blood vessels to relax, resulting in vasodilation.  

Excretion and elimination: 

nitroglycerin and its metabolites are excreted mainly in the urine. The half-life of nitroglycerin is short, about 1-4 minutes, which means that it is rapidly eliminated from the body. 

Adminstartion

Administration:  

To avoid potential dizziness or fainting, it is important to ensure that the patient is in a seated or lying position prior to administering nitroglycerin.  

Check the medication label and expiration date to ensure that the medication is still effective.  

Open the medication package and remove the nitroglycerin tablet or spray. 

If using a tablet, place it under the tongue and allow it to dissolve completely. Do not swallow the tablet, chew it, or crush it.  

If using a spray, hold the container upright and place the nozzle under the tongue. Depress the spray button once and allow the medication to be absorbed.  

If the patient’s chest pain is not relieved after the first dose of nitroglycerin, administer a second dose after 5 minutes. If the pain persists after the second dose, seek medical attention immediately. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: nitroglycerin sublingual 

Why do we use nitroglycerin sublingual?  

nitroglycerin is a medication commonly used for the treatment of angina (chest pain) and heart failure. nitroglycerin, when administered sublingually (under the tongue), has the ability to rapidly enter the bloodstream. This can alleviate symptoms of angina by dilating or widening the blood vessels. As a result, the heart’s workload is reduced, and blood flow to the heart muscle is improved. 

Sublingual nitroglycerin is particularly effective for the treatment of angina because it is absorbed rapidly through the mucous membranes under the tongue, bypassing the digestive system and liver metabolism, which can delay the onset of action of the medication. This allows for quick relief of angina symptoms, such as chest pain, tightness or discomfort, and shortness of breath.