Nitrates short-acting

Because of die risk of tolerance to oral nitrates developing, die primary care provider may prescribe die short-acting preparations 2 to 3 times daily, witii die last dose no later than 7 pm and die sustained release preparations once daily or twice daily at 8 AM and 2 PM. 

All patients with IHD should receive a prescription for short-acting nitrates and education regarding their use. Points to emphasize when counseling a patient on nitroglycerin use include ... 

Sodium nitroprusside (SNP) is both a venous and an arterial vasodilator. An important part of its vasodilator action is caused by the release of nitric oxide (NO), similarly as for the organic nitrates. SNP can only be administered via the intravenous route. It is a rapidly and short acting vasodilator. It has been used in the treatment of hypertensive emergencies and in the management of myocardial ischaemia. In spite of its vasodilator action it hardly influences heart rate, in contrast to hydralazine and minoxidil. The dosage of SNP should not be higher than 3 pg/kg/min within 48 h, in order to avoid the rise of cyanide ions and thiocyanate in the blood. 

Short-acting nitrates, such as nitroglycerin, are predominantly used for the suppression of acute anginal symptoms. The well-known sublingual (oro-mucosal) route of administration is characterised by... 

The interval after which even short-acting nitrates can be safely given after the use of sildenafil is likely to be substantially longer than 24 hours when elderly patients are concurrently taking a CYP3A4 inhibitor, such as diltiazem. 

Nitrates have been produced in many chemical forms, but the current choice lies between the rapid-onset, short-acting glyceryl trinitrate (nitroglycerin) and the longer-acting isosorbide mononitrate and isosorbide dinitrate. 

When using long-acting nitrates, it is important to schedule a 10- to 12-hour nitrate-free interval to minimize tolerance. With continuous exposure to nitrates, tolerance or the loss of antianginal and hemodynamic effects occurs. When exposure is discontinued, symptoms of withdrawal (severe headache, chest pain, or sudden cardiac death) can occur. Short-acting nitrates are not likely to lead to tolerance due to their rapid onset of action and short duration. 

Organic Nitrates Organic nitrates are available in a number of formulations that include rapid-acting nitroglycerin tablets or spray for sublingual administration, short-acting oral agents... 

This hypothesis clearly contradicted a large body of clinical evidence that nitrates were effective. Some years later, using more sensitive and reliable analytical methods, this interpretation was shown to be incorrect, and the clinical utility of long-acting, oral organic nitrate derivatives affirmed. In 1967, one of the pharmacodynamically active metabolites of ISDN, IS-5N, was shown to be formed in vivo, and shortly thereafter it was introduced as a novel long-acting NO donor with improved bioavailability. 

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