My father is taking pravastatin 20mg for high cholesterol. Total cholesterol, LDL & HDL are normal but triglycerides are 250. Why is this & what to do?

Change medication. Assuming he is following a prudent, cholesterol-lowering diet and exercise plan, Pravastatin is not created with the intent of lowering the triglycerides, no matter what dose he tries. Lipitor (atorvastatin) and Crestor will lower the cholesterol at safe doses, but they may be more expensive than Pravastatin, depending on his insurance plan. But they will lower the triglycerides and keep LDL and HDL in check.