Selepeg 400mcg Tablet is a pulmonary vasodilator medication that belongs to a class of drugs called prostacyclin receptor agonists containing the active ingredient Selexipag. It is used to treat pulmonary arterial hypertension (PAH) to improve exercise capacity and delay disease progression. Pulmonary arterial hypertension is a serious and rare medical condition caused by high blood pressure in the arteries that supply the lungs. It primarily affects the small blood vessels (arteries) in the lungs, leading to their narrowing and increased resistance to blood flow. This drug is contraindicated in individuals with known hypersensitivity or allergy to it or its component. It is also contraindicated if you have certain heart conditions such as severe coronary heart disease, unstable angina, recent heart attack, decompensated cardiac failure, severe irregular heartbeat, or certain heart valve defects. Also, if you have had a stroke within the last three months or any other event that reduces blood supply to the brain or are taking gemfibrozil (a medication used to lower lipid levels), this drug should not be taken. If you have issues with your thyroid gland, it is necessary to inform your physician. Thyroid problems can impact the treatment plan, and your doctor will consider the potential effects of this drug on your condition. This drug is contraindicated during pregnancy because it can harm a developing fetus, and breastfeeding is not recommended in patients taking Selepeg 400mcg Tablet because it is unknown whether the medicine passes into the breast milk and harms your baby. This drug is metabolized and excreted by the kidneys, so if you have severe kidney problems or are undergoing dialysis, your doctor needs to determine the appropriate dosage or prescribe an alternative medicine if necessary.