Drugs for inflammatory and Related Disorders_histamine/antihistamines

Question 1

________ is an autacoid present at high levels in lungs, skin and GIT

Answer 1

Histamine

Question 2

______ is released from mast cells and basophil by HSR type I, drugs, venoms and trauma

Answer 2

Histamine

Question 3

Histamine is released by ______ and ______ cells via HRS Type I, drugs, venoms and trauma

Answer 3

Mast and Basophil cells

Question 4

Histamine receptors are of serpentine family with___________ with ____________ effectors

Answer 4

7 transmembrane-spanning domain; G-protein coupled 2nd messenger

Question 5

what are the effects of H1 activation?

Answer 5

increases capillary dilation (via NO—> decreased BP);
increases capillary permeability —-> increases edema
increase bronchiolar smooth muscle contraction via IP3 and DAG release
increase activation of peripheral nociceptive receptors —-> increases pain and pruitus
decrease AV nodal conduction

Question 6

what are the effects of H2 activation?

Answer 6

increases gastric acid secretion —> increase GI ulcers

Increase SA nodal rate, positive inotropism and automaticity

Question 7

H1 antagonists acts as _________________ of histamine and could sometimes be ineffective incases of high histamine levels

Answer 7

Competitive antagonist

Question 8

all antihistamines require____________ and most cross ________

Answer 8

hepatic metabolism and placental barrier

Question 9

Antihistamines are

Answer 9

reversible inhibitors of H1 histamine receptors

Question 10

Name the 1st Generation antihistamines

Answer 10

Diphenhydramine, chlorpheniramine; dimenhydramine, prmethazine; meclizine

Question 11

Name the 2nd Generation antihistamines

Answer 11

Loratadine, fexofenadine, desloratadine, cetirizine

Question 12

widely OTC (over-the -counter) drug

Answer 12

diphenhydramine

Question 13

Some alpha block and local anesthetic action via?

Answer 13

promethazine

Question 14

Possible CNS stimulation via?

Answer 14

chlorpheniramine

Question 15

Highly effective in motion sickness 1st generation antihistamines

Answer 15

Meclizine

Question 16

adverse effects of 2nd generation antihistamines are

Answer 16

less sedating than 1st generation b/c of less entry into CNS

Question 17

clinical uses of 2nd generation antihistamines

Answer 17

allergy (hay fever, rhinitis, urticaria)

Question 18

Clinical uses of 1st generation antihistamines

Answer 18

motion sickness, vertigo; nausea, vomiting with preg; preoperative sedation; sleep aid, cold medications (OTC) and acute EPSs

Question 19

Adverse effects of 1st generation antihistamines

Answer 19

Sedation, antimuscarnic, anti-alpha adrenergic