Is it safe to take Asprin without prescription?

Q: It it true that Asprin prevents heart attack by thinning the blood? I give it to my father without prescription. Is it safe?

A:Aspirin is indicated in the treatment of (a) fever, (b) pain (such as migraine) and (c) as blood thinner when given in small dose (50 to 150 mg) daily to patients at risk of stroke and heart attacks. It is not a tonic. If given without any reason and for long periods, it can cause stomach ulcers, bleeding, asthmatic symptoms, salicylism etc.