Isordil Special Precautions

As with other vasodilators, isosorbide dinitrate may cause paradoxical side effects in sensitive patients, which may increase ischemia and may even lead to extension of myocardial damage and advanced congestive heart failure. If one elects to use organic nitrates in the early infarction, hemodynamic monitoring and frequent clinical assessment should be used because of the potential deleterious effects of hypotension. Sildenafil may amplify the vasodilatory effects of nitrates such as Isordil and can result in severe hypotension. Appropriate supportive care has not been studied, but it seems reasonable to treat this as a nitrate overdose.
Severe hypotensive response, particularly with upright posture, may occur with even small doses of isosorbide dinitrate. Paradoxical bradycardia and increased angina pectoris may accompany nitrate-induced hypotension. The drug should be used with caution in subjects who may have blood volume depletion from diuretic therapy or in subjects who have low systolic blood pressure (e.g. below 90 mm Hg).
In the treatment of acute or chronic cardiac failure, pulmonary capillary pressure should not be allowed to fall below 15 mm Hg or systolic blood pressure below the physiological range in normal or hypertensive patients. Systolic pressure should be preserved in patients with pre-existing hypotension in the range of 90-100 mm Hg.
Marked symptomatic, orthostatic hypotension has been reported when calcium channel blockers and organic nitrates were used in combination. Dose adjustment of either class of agents may be necessary.
Nitrate therapy may aggravate the angina caused by hypertrophic cardiomyopathy.
Tolerance to this drug and cross tolerance to other nitrates and nitrites may occur. The importance of tolerance to the appropriate use of isosorbide dinitrate in the management of patients with angina pectoris has not been determined.
In clinical trials in angina patients, there are reports of angina attacks being more easily provoked and of rebound in the hemodynamic effects soon after nitrate withdrawal. It seems prudent therefore, to gradually withdraw patients from isosorbide dinitrate when therapy is being terminated, rather than stopping the drug abruptly.
Carcinogenesis, Mutagenesis, Impairment of Fertility: No long-term studies in animals have been performed to evaluate the carcinogenic potential of this drug. A modified two-litter reproduction study in rats fed isosorbide dinitrate at 25 or 100 mg/kg/day did not reveal any effects on fertility or gestation or any remarkable growth pathology in any parent or offspring fed isosorbide dinitrate as compared with rats fed a basal-controlled diet.
Effects on Ability to Drive and Use Machines: See information as previously mentioned.
Use in Children: The safety and effectiveness of isosorbide dinitrate in children has not been established.
Use in the Elderly: Clinical studies of isosorbide dinitrate Sublingual and Oral Tablets did not include sufficient number of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in response between the elderly and younger patients.
In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.