Do nitrates differ?

1. The organic nitrates all share a common biochemical and physiological mechanism of action. 2. The organic nitrates differ substantially in their pharmacologic potency and pharmacokinetics. In vitro potency differences appear larger than the corresponding in vivo activities. 3. The duration of action of organic nitrates, after a single immediate-release dose, is governed by the pharmacokinetics of the drug. However, the duration of action of available sustained-release preparations, whatever the nitrate or formulation, is limited to about 12 h, due to the development of pharmacologic tolerance. 4. Nitrates do not appear to differ in their production of undesirable effects.