When a drug binds to the receptor and causes action opposite to that of agonist this is called as?

ANSWER: (C) Inverse agonistREF: Goodman and Gillman 11th edition page 14-15, http://en.wikipedia.org/wiki/Inverse_agonistIndirect repeat from June 2008An inverse agonist is an agent that binds to the same receptor as an agonist but induces a pharmacological response opposite to that agonist.A neutral antagonist has no activity in the absence of an agonist or inverse agonist but can block the activity of eitherAn agonist increases the activity of a receptor above its basal level while an inverse agonist decreases the activity below- the basal level.A partial agonist binds to the receptor and causes action submaximal to that of agonist