Take tablets orally with water, with or without food. Do not crush or chew. For acute attacks, sublingual forms are preferred.

Isosorbide Dinitrate is metabolized to nitric oxide (NO), which activates guanylate cyclase, leading to an increase in cyclic GMP (cGMP). Increased cGMP causes dephosphorylation of myosin light chains in smooth muscle, resulting in relaxation of vascular smooth muscle cells. This leads to venodilation (reduced preload) and arterial dilation (reduced afterload), decreasing cardiac workload and improving myocardial oxygen supply.

• •Hypersensitivity to nitrates
• •Severe anemia
• •Closed-angle glaucoma
• •Concurrent use with phosphodiesterase-5 (PDE5) inhibitors (e.g., sildenafil, tadalafil) due to risk of severe hypotension
• •Increased intracranial pressure
• •Circulatory collapse and severe hypotension

Store below 30°C in a dry place, away from light and moisture. Keep out of reach of children.

Symptoms include severe hypotension, tachycardia, flushing, headache, nausea, vomiting, methemoglobinemia. Treatment involves elevating legs, administering IV fluids, and if necessary, vasopressors. For methemoglobinemia, methylene blue may be required.

Pregnancy Category C. Use only if clearly needed and the potential benefits outweigh the potential risks to the fetus. It is unknown if Isosorbide Dinitrate is excreted in breast milk; use with caution in breastfeeding mothers.