 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  lungs is a serious condition that can harm both a pregnant woman and her unborn baby, do not stop this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, talk to your doctor about the benefits and risks of using sildenafil. This medication passes into breast milk in small amounts. Consult your doctor before breast-feeding.The interactions of Viagra Oral: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug are: riociguat, vericiguat. Sildenafil can cause a serious drop in your blood pressure when used with nitrates. A serious drop in blood pressure can lead to dizziness, fainting, and rarely heart attack or stroke. Do not use sildenafil with any of the following: certain drugs used to treat chest pain/angina (nit </s>