In order to elucidate the various pathways and efficacy of nitroglycerin, it is crucial to comprehend how different formulations are metabolised within the body. Nitroglycerin exhibits rapid absorption through the skin, gastrointestinal (GI) tract, and mucous membranes. According to Sear (2019), when administered orally, sublingual administration is preferred as it allows for efficient absorption and rapid uptake into the bloodstream. In contrast, Isosorbide mononitrate tablets bypass first-pass metabolism, resulting in 100% bioavailability. A significant distinction exists in terms of onset of action between oral tablets (30 to 60 minutes) and sublingual tablets or sprays (1 to 3 minutes). Buccal tablets, when held in the mouth, provide a similar effect but offer extended duration of action over several hours, as mentioned by Doogue & Polasek (2013). They further clarify that bioavailability refers to the amount of drug available in the circulation. In the case of orally administered medications, bioavailability is influenced by both absorption and first-pass metabolism. This distinction is crucial when a patient presents with angina or chest pain.
NURS 6566 Week 1 discussion
In addition to oral routes such as tablets, sublingual sprays, and buccal tablets, nitroglycerin can also be administered via transdermal ointment or patch. In a hospital setting, it is also given intravenously. The intravenous route offers rapid onset, but nitroglycerin is broken down in the blood vessels. The manner in which nitroglycerin enters the circulation determines the maximum concentration achieved and the time taken to reach this maximum concentration. Rahul & Shikha (2019) describe the development of an oral film for the administration of nitroglycerin, particularly suitable for geriatric patients, pediatric patients, or those with dysphagia. The film can be ingested without water and eliminates the risk of choking. Films are advantageous for administering drugs that are unstable in acidic or alkaline environments, such as the stomach and intestines, respectively. They facilitate rapid dissolution, fast absorption, drug release, and prompt onset of action. Transdermal patches, when applied to the skin, demonstrate good absorption and provide sustained bioavailability over an extended period. NURS 6566 Week 1 discussion
References:
Divakaran, S., & Loscalzo, J. (2017). The role of nitroglycerin and other nitrogen oxides in cardiovascular therapeutics. Journal of the American College of Cardiology, 70(19), 2393-2410.
Doogue, M. P., & Polasek, T. M. (2013). The ABCD of clinical pharmacokinetics. Therapeutic Advances in Drug Safety, 5–7. https://doi.org/10.1177/2042098612469335
Rahul, S., & Shikha, A. (2019). FORMULATION AND EVALUATION OF NITROGLYCERINE ORAL FILM.
Sear, J. W. (2019). Antihypertensive Drugs and Vasodilators. Pharmacology and Physiology for Anesthesia (2nd ed.)
