Selepeg 400 Tablet is a prescription medicine used to treat pulmonary arterial hypertension (high pressure in the blood vessels that carry blood from the heart to the lungs). It helps to improve your exercising ability and will prevent the disease from getting worse. Selepeg 400 Tablet can be taken with or without food. Take it regularly and take it at the same time each day to help you remember. Do not skip any doses and finish the full course of treatment even if you feel better. Do not stop taking the medicine suddenly without talking to your doctor.Common side effects of this medicine include headache, diarrhea, jaw pain, nausea,myalgia, vomiting, pain in extremity, and flushing. Generally, most of its side effects usually resolve on their own and do not need any medical attention. However, you should consult with the doctor if you are bothered by any of the side effects.Before using this medicine, let your doctor know if you have any preexisting medical conditions. Let your doctor also know about all the other medicines you are taking. Additionally, if you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor before using this medicine. As it may cause harmful effects to the developing baby.