a drug that binds to non active site of receptor and decreases constitutive activity of receptor is known as

The drug you're referring to is known as an "Inverse Agonist."

Here's a step-by-step explanation:

1. A receptor in the body can have what's known as "constitutive activity," which means it can activate itself without a substance (like a drug or hormone) binding to it.

2. An inverse agonist is a type of drug that binds to the same receptor as an agonist (a substance that activates a receptor), but it has the opposite effect.

3. Instead of activating the receptor, an inverse agonist decreases the receptor's activity.

4. Importantly, the inverse agonist doesn't bind to the active site of the receptor (where an agonist would normally bind). Instead, it binds to a different site. This is why it's able to decrease the receptor's activity instead of increasing it.

5. So, an inverse agonist can decrease the constitutive activity of a receptor by binding to a non-active site.