Q- Which of the following is the mechanism of action of metoprolol in treating hypertension and arrhythmias?
A- β1 -Selective adrenoreceptor agonist
B- β1 -Selective adrenoreceptor antagonist
C- Blocks Ca 2+ entry in vascular smooth muscle cells
D- Reduces production of angiotensin II
B- β1 -Selective adrenoreceptor antagonist- Metoprolol is a selective beta-blocker.
Q- Which of the following is the receptor site of action of sumatriptan?
A- Dopamine receptor
B- GABAB receptor
C- Glycine receptor
D- Serotonin 5-HT
D- Serotonin 5-HT- Sumatriptan activate this receptor which inhibits the activity of adenylyl cyclase to decrease cAMP accumulation leading to contraction of arterial smooth muscle in carotid and cranial circulation.
Q- Which of the following drugs is a weak partial agonist of estrogen receptor in most tissues?
A- Clomiphene
B- Fulvestrant
C- Raloxifene
D-Tamoxifen
A- Clomiphene- It is the only one on the list that is weak partial agonist of estrogen receptor. Fulvestrant is a pure anti-estrogen. Raloxifene and tamoxifen are estrogen antagonists but their activity is tissue-specific.
