Here are some steps that might help: If you smoke, quit. Store mixed oral liquid in the refrigerator. Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient. From there, you can explain your situation using the list that you created. If you do not have one yet, a primary care doctor can still give you a proper diagnosis. In addition to your prepared questions, don’t hesitate to ask additional questions during your appointment. What’s the best treatment? · Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way. Dosing. Your doctor may adjust your dose as needed and tolerated. However the dose is usually not more than 40 mg 3 times a day. Children 1 year of age and older weighing 20 to 45 kg—20 mg 3 times a day. Due to this interaction, doctors typically will not prescribe Viagra with these drugs. Examples include: riociguat (Adempas) sildenafil (Revatio) tadalafil (Adcirca) Viagra and other erectile dysfunction (ED) medications. Because Viagra may interact with other medications for ED, doctors typically will not prescribe Viagra with these drugs. Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or .