From the Guidelines
Short-acting nitroglycerin should be administered sublingually at a dose of 0.3-0.4 mg every 5 minutes for up to 3 doses to patients with continuing ischemic pain, as recommended by the 2014 AHA/ACC guideline 1.
Key Points
- Short-acting nitroglycerin medications are available in sublingual tablets, spray, and ointment forms, providing rapid relief of angina symptoms.
- The typical regimen for acute angina is to take one dose, wait 5 minutes, and if pain persists, take a second dose, with a third dose possible after another 5 minutes if needed, as per the guidelines 1.
- If pain continues after three doses in 15 minutes, emergency medical attention should be sought.
- These medications work by dilating blood vessels, increasing blood flow to the heart muscle, and reducing the heart's workload.
- Side effects may include headache, dizziness, and hypotension, and patients should sit or lie down when taking nitroglycerin to prevent falls from sudden blood pressure drops, as cautioned in the European Society of Cardiology guidelines 1.
Important Considerations
- Patients should be instructed on how to use short-acting nitroglycerin for acute symptom relief and situational prophylaxis, with appropriate monitoring and follow-up, as recommended by the European Heart Journal 1.
- The use of short-acting nitrates may be associated with an increased risk of orthostatic hypotension, headaches, flushing, and rash, and may lead to attenuation or loss of the anti-ischaemic effect during continuous nitrate medication (tolerance), as noted in the 2022 review by the European Society of Cardiology working group on cardiovascular pharmacotherapy 1.
- Therefore, the smallest effective dose of short-acting nitroglycerin should be used for relief of angina, and patients should be monitored for potential side effects and interactions with other medications, as emphasized in the guidelines 1.
From the Research
Short Acting Nitro Types
- Short-acting nitrates, such as nitroglycerin, are commonly used to provide rapid therapeutic relief of acute recurrent angina attacks 2
- They work by inducing vasodilation in large capacitance blood vessels, increasing epicardial coronary arterial diameter and coronary collateral blood flow, and impairing platelet aggregation 2
- Sublingual nitroglycerin, administered either as a sublingual tablet or spray, can complement anti-anginal therapy as part of optimal medical therapy in patients with refractory and recurrent angina 2
Forms of Short Acting Nitrates
- Sublingual spray formulation provides several clinical advantages compared to tablet formulations, including a lower incidence of headache and superiority to the sublingual tablet in terms of therapeutic action and time to onset 2
- Isosorbide dinitrate is another short-acting nitrate that can be used to treat angina pectoris, and higher than recommended dosages may be effective in some patients 3
Tolerance to Short Acting Nitrates
- Long-acting nitrates can develop tolerance during sustained therapy, which means their clinical efficacy is decreased during long-term use 4, 5, 6
- Short-acting nitrates, such as sublingual nitroglycerin, maintain their full anti-ischemic effect even after long-term use of long-acting nitrates, but may attenuate their effect during continuous treatment 4
- A daily low-nitrate interval is required to prevent tolerance development, and intermittent therapy with once-daily ingestion of high-dose sustained-release isosorbide dinitrate can prevent tolerance 5