Nitrates are available in different forms.
Sublingual nitrates are generally placed under the tongue where they dissolve and are absorbed through the lining of the mouth. Some can also be used buccally, being placed under the lip or in the cheek. The chewable dosage forms, after being chewed and held in the mouth before swallowing, are absorbed in the same way. It is important to remember that each dosage form is different and that the specific directions for each type must be followed if the medicine is to work properly . Nitrates work by relaxing blood vessels and increasing the supply of blood and oxygen to the heart while reducing its work load.