Question

This is a second time I ask this question, as the first time I didn't get proper answer. I need the exact option from the listed above. Thanks

Diphenhydramine (Benadryl^®) is an antihistamine. This drug is given to the patient approximately 30 minutes before infusion of the T cells in order to treat any immune reactions that may occur as a result of the infusion. Histamine acts as a full agonist at its receptor, the HA receptor, as part of an inflammatory reaction. Diphenhydramine works by inhibiting histamine from binding to this receptor, reducing the negative symptoms associated with histamine HA-receptor binding. Based on this information, diphenhydramine binds at ____________ site on the HA receptor and so most likely acts as a ____________.

1 an alternative; non-competitive antagonist

2 the active; non-competitive antagonist

3 an alternative; competitive antagonistincorrect

4 the active; competitive antagonist

5 an alternative; partial agonist

6 an alternative; full agonist

7 the active; partial agonist

8 the active; full agonist

Answer 1

Diphenhydramine binds at the active site on the HA receptor and so most likely acts as a competitive antagonist.

Then only, Diphenhydramine can act as an antihistamine.