Pravastatin dosage. Your dose will be based on your condition, age, and other medication you might be taking. The typical recommended starting dose of pravastatin for adults is 40 milligrams (mg) a day. Some patients may take 80 mg a day. In children, the typical dose is 20 mg a day. Your doctor may start you on a low dose of pravastatin and gradually increase it. You should try to take pravastatin at the same time every day.