Question

Why do drugs causes side effect?

Answer 1

All medicines can cause unwanted side effects. For example, antibiotics such as those in the sulfonamide and penicillin families cause allergic reactions in around five per cent of the population. Skin rashes are a common reaction. However, whether a reaction is caused by the medicine or the illness that it is used to treat is sometimes difficult to tell.

Answer 2

Heyy mate..here is ur answer..
.
.
Drugs causes side effects when they are overdosed..when overdosed they r not able to perform their particular function..
..
..
hope it helps..thnku