Silagra 100 Mg contains sildenafil, so it should be avoided with nitrates at all times unless a qualified clinician specifically determines otherwise. Sildenafil can significantly increase the blood-pressure-lowering effect of nitrate medicines, potentially causing dangerous hypotension. Nitrates include medicines such as nitroglycerin and other organic nitrates or nitrites, including those used intermittently for chest pain. The contraindication applies whether nitrates are taken regularly or only occasionally. Importantly, after taking sildenafil, the prescribing information says it is unknown when nitrates can be safely administered; even at 24 hours, safe co-administration has not been established. If someone has taken Silagra and develops chest pain, they should tell emergency medical personnel that sildenafil was taken and should not self-administer a nitrate.