Aspirin (Reasons for use)
Treats pain, fever, arthritis, and inflammation. It may also be used to reduce the risk of heart attack.
  
Aspirin (Mechanisms of action)
It prevents blood from clotting by blocking the production of platelets of thromboxine A2. It accomplishes this by inhibiting COX-1 which produces the thromboxine A2.
Aspirin (side effects)
Upset stomach, heartburn, Severe stomach pain
Bloody vomit or vomit that looks like coffee grounds, Blood in stools or urine, Skin rash or hives with intense itching, Swelling of the face or eyelids, Wheezing or trouble breathing, Severe dizziness or drowsiness, Ringing in the ears
Coumadin (reason for use)
Helps to prevent new blood clots from forming, and helps to keep existing blood clots from getting worse. This medicine is a blood thinner (anticoagulant).
Coumadin (Side effects)
Bleeding (in stool, vomit, gums, etc), bruising, weakness
Coumadin (Mechanisms of action)
Suppresses production of some clotting factors (interfering with prothrombin activiation) and thereby inhibiting clotting of blood.
Statins (reason for use)
Statins are a class of drugs used to lower cholesterol levels by inhibiting the enzyme HMG-CoA reductase, which plays a central role in the production of cholesterol in the liver
Statins (Side effects)
Muscle pain and damage, liver damage, digestive problems, rash and flushing, increased blood sugar for type 2 diabetes,Decreased cognition.
Statins (Mechanisms of action)
Block the enzyme in the liver responsible for making cholesterol. This enzyme is called HMG-CoA reductase.

PPI's like Pantoprazole (reason for use)
Treats gastroesophageal reflux disease (GERD) and damage to the esophagus. Also treats high levels of acid in the stomach caused by a tumor (such as Zollinger-Ellison syndrome). This medicine is a proton pump inhibitor (PPI)
PPI's (Side effects)
Diarrhea, nausea, or stomach pain, Headache, Mild skin rash
PPI's (Mechanisms of action)
Block the enzyme in...