Som ved behandling med andre vasodilatorer, skal der udvises ekstra forsigtighed hos patienter, der lider af aorta - eller mitralstenose eller obstruktiv hypertrofisk kardiomyopati.
Aortic and mitral valve stenosis, obstructive hypertrophic cardiomyopathy: as with other vasodilators, special caution is indicated in patients suffering from aortic or mitral stenosis, or obstructive hypertrophic cardiomyopathy.