Chapter 189 - Antihistamines Flashcards
TABLE 189-1
Basic Pharmacology of Antihistamines
Fill in the blanks
_____ antihistamines are _____ agonists that reversibly bind and stabilize the inactive form of the histamine receptor, thereby favoring the inactive state.
Both H1 and H2 antihistamines are inverse agonists that reversibly bind and stabilize the inactive form of the histamine receptor, thereby favoring the inactive state.
TABLE 189-1
Basic Pharmacology of Antihistamines
Fill in the blanks
_____ agents are relatively lipophilic, which enhances penetration of the blood–brain barrier and leads to sedation.
First-generation H1 agents are relatively lipophilic, which enhances penetration of the blood–brain barrier and leads to sedation.
TABLE 189-1
Basic Pharmacology of Antihistamines
Fill in the blanks
_____ antihistamines may interact with other drugs metabolized by the hepatic cytochrome P450 system leading to drug–drug interactions.
First-generation H1 antihistamines may interact with other drugs metabolized by the hepatic cytochrome P450 system leading to drug–drug interactions.
TABLE 189-1
Basic Pharmacology of Antihistamines
Fill in the blanks
_____ antihistamines have poor penetration of the blood–brain barrier and thus are less sedating.
Second-generation H1 antihistamines have poor penetration of the blood–brain barrier and thus are less sedating.
TABLE 189-1
Basic Pharmacology of Antihistamines
Fill in the blanks
_____ antihistamines bind selectively to peripheral H1 receptors and have fewer CNS effects.
Second-generation H1 antihistamines bind selectively to peripheral H1 receptors and have fewer CNS effects.
TABLE 189-1
Basic Pharmacology of Antihistamines
Fill in the blanks
_____ antihistamines require less hepatic metabolism and thus are less likely to interact with other medications.
Second-generation H1 antihistamines require less hepatic metabolism and thus are less likely to interact with other medications.
TABLE 189-1
Basic Pharmacology of Antihistamines
Fill in the blanks
There is no evidence of _____ or _____ to first-generation or second-generation antihistamines.
There is no evidence of tolerance or tachyphylaxis to first-generation or second-generation antihistamines.
TABLE 189-2 vs TABLE 189-6
Indications for Treatment with H1 Antihistamines vs Dermatologic Indications for Treatment with H2 Antihistamines
Acute urticaria
H1 Antihistamines
TABLE 189-2 vs TABLE 189-6
Indications for Treatment with H1 Antihistamines vs Dermatologic Indications for Treatment with H2 Antihistamines
Chronic idiopathic urticarial
H1 Antihistamines
TABLE 189-2 vs TABLE 189-6
Indications for Treatment with H1 Antihistamines vs Dermatologic Indications for Treatment with H2 Antihistamines
Physical urticarias and dermatographism
H1 Antihistamines
TABLE 189-2 vs TABLE 189-6
Indications for Treatment with H1 Antihistamines vs Dermatologic Indications for Treatment with H2 Antihistamines
Pruritus associated with histamine release
H1 Antihistamines
TABLE 189-2 vs TABLE 189-6
Indications for Treatment with H1 Antihistamines vs Dermatologic Indications for Treatment with H2 Antihistamines
Symptoms of mastocytosis
H1 Antihistamines
TABLE 189-2 vs TABLE 189-6
Indications for Treatment with H1 Antihistamines vs Dermatologic Indications for Treatment with H2 Antihistamines
Acute allergic reactions
H2 Antihistamines
TABLE 189-2 vs TABLE 189-6
Indications for Treatment with H1 Antihistamines vs Dermatologic Indications for Treatment with H2 Antihistamines
Chronic urticaria (as a second-line agent)
H2 Antihistamines
TABLE 189-2 vs TABLE 189-6
Indications for Treatment with H1 Antihistamines vs Dermatologic Indications for Treatment with H2 Antihistamines
Systemic symptoms associated with mastocytosis (especially GI related)
H2 Antihistamines
TABLE 189-3
Dosing Regimens for H1 Antihistamines
CONDITIONS REQUIRING
DOSAGE ADJUSTMENT
Hepatic vs Renal vs Both
Chlorpheniramine
Hepatic impairment
TABLE 189-3
Dosing Regimens for H1 Antihistamines
CONDITIONS REQUIRING
DOSAGE ADJUSTMENT
Hepatic vs Renal vs Both
Cyproheptadine
Hepatic impairment
TABLE 189-3
Dosing Regimens for H1 Antihistamines
CONDITIONS REQUIRING
DOSAGE ADJUSTMENT
Hepatic vs Renal vs Both
Diphenhydramine
Hepatic impairment
TABLE 189-3
Dosing Regimens for H1 Antihistamines
CONDITIONS REQUIRING
DOSAGE ADJUSTMENT
Hepatic vs Renal vs Both
Hydroxyzine
Hepatic impairment
TABLE 189-3
Dosing Regimens for H1 Antihistamines
CONDITIONS REQUIRING
DOSAGE ADJUSTMENT
Hepatic vs Renal vs Both
Tripelennamine
Hepatic impairment
TABLE 189-3
Dosing Regimens for H1 Antihistamines
CONDITIONS REQUIRING
DOSAGE ADJUSTMENT
Hepatic vs Renal vs Both
Acrivastine
Renal impairment
TABLE 189-3
Dosing Regimens for H1 Antihistamines
CONDITIONS REQUIRING
DOSAGE ADJUSTMENT
Hepatic vs Renal vs Both
Azelastine
Renal and hepatic impairment