PAN 20 MD Tablet is also used to prevent stomach ulcers and acidity that may be seen with the prolonged use of painkillers. It belongs to a class of medicines known as proton pump inhibitors (PPIs). This medicine should be taken one hour before a meal, preferably in the morning. The dose will depend on your underlying condition and how you respond to the medicine. You should keep on taking it as prescribed even if your symptoms disappear quickly.