Antihistamines Flashcards Preview

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Flashcards in Antihistamines Deck (22)
0

Cetirizine

H1 antihistamine

Second Generation antihistamine

Highly selective for H1 sites

Few anti-cholinergic side effects

Penetrate poorly into CNS, reducing sedative effects

1

Cyclizine

H1 antihistamine

First Generation Antihistamine

SLIGHT Sedation

Used in MOTION SICKNESS/Emesis

2

Dimenhydrinate

First Generation Antihistamine

HIGH SEDATION effect

Used to treat motion sickness

3

Diphenhydramine

First Generation Antihistamine

HIGH SEDATION

USED to treat MOTION SICKNESS
Used in Non-H1 effects for LOCAL ANESTHESIA

4

Fexofenadine

H1 Antihistamine

Second Generation antihistamine

LOW SEDATION
- highly selective for H1 sites and have few anti-cholinergic side effects
- Penetrate poorly into CNS, reducing sedative effects

5

Loratadine

H1 antihistamine

Second Generation antihistamine

LOW Sedation
- High selectivity for H1 sites and have few anti-cholinergic side effects
- Penetrate poorly into the CNS, reduce sedative effects

6

Promethazine

H1 antihistamine

Used in treatment of Motion sickness/emesis
- Very Effective

Used as local anesthetic by BLOCKING SODIUM CHANNELS

Causes SEDATION
- Used as antiemetic

7

Adalimumab

Anti-TNF alpha

HUMAN antibody to TNF alpha
- Mechanism: binds TNF to prevent interaction with receptor
- Reduces circulating and localized levels of TNF

Application:
- Inflammatory disease involving TNF
- Parenteral Administration required
- Rh ART, used in COMBO with METHOTREXATE
- Elevated TNF in joints
- Crohn's disease, used in COMBO with AZATHIOPRINE
- Elevated TNF in stool

Complications
- Increased frequency of infections (upper respiratory, urinary)

8

Etanercept

Anti-TNF agent

Fusion protein containing:
- Ligand binding domain of TNF receptor
- and Fc domain of IgG

Mechanism:
- Bind to TNF alpha binding domain to prevent interaction with receptor

Applications:
- Parenteral administration required
- Rh arthritis, used in combo with methotrexate
- Crohn's disease, used in combo with azathioprine

Complications:
- increased frequency of infections (upper respiratory, urinary)

9

Infliximab

Anti-TNF alpha agent

Humanized antibody to TNF

Binds to TNF alpha
- Prevents interaction with receptor
- reduces circulating and localized levels of TNF

Applications:
- Parenteral administration required
- Rh, used in combo with methotrexate
- Crohn's disease, used in combo with azathioprine

Complications
- Increased frequency of infections (upper respiratory, urinary)

10

Anakinra

Anti-IL-1 Agent

Competitive IL-1 R antagonist

Useful in treating Rh ART
- Possibly other inflammatory diseases

Short half life, daily injection required

Increased susceptibility to infection

11

Tofacitinib

Jak kinase inhibitor

Treatment in Rh ART

Administration: Oral

Second line treatment for Rh ART

Mechanism:
- Inhibits all activity of cytokines required for adaptive immunity (IL-2, 4)
- Inhibits activities of inflammatory cytokines: IL-

THERAPEUTIC DOSE: 5 mg bid (twice a day)
- Higher doses to produce potent immunosuppression AND adverse effects

Adverse effects:
-Anemia, neutropenia, general myelosuppression
- Increase risk of infection (herpes zoster)

Effect: Comparable to anti TNF in reducing active disease in Rh ART

12

Aspirin

Nonselective COX inhibitor

Prototypical NSAID inhibits COX-1 and COX-2
- IRREVERSIBLY inhibits COX enzymes
- Only NSAID with cardiovascular protective effects

Irreversibly inhibits COX-1 so no TXA2 for life of platelet (7-10 days)

Rapidly converted to salicylic acid
- Main portion of aspirin is acetyl group that acts as a acetyl group to permanently inhibit COX

All metabolites excreted in urine
- If elimination saturates beyond 600 mg, total body load and half life increase to 12-16 hours from 3-5

Selectivity (IC50): 4.4
- IC50 is (COX-2/COX-1):
- IC50 COX-1: 1.7
- IC 50 COX-2: 7.5

Analgesic/antipyretic
Cardiovascular prophylaxis
- Due to reduced platelet aggregation

Intolerance:
- SALICYLISM: Hypersensitivy to ASA
- Hyperventilation, tinnitus, vertigo, emesis, sweating
- Reye's Syndrome: Associated with ASA and other salicylates used in children with viral illness
- Acute encephalopathy, fatty liver degeneration
- Associated with viral diseases and viral vaccines

Adverse effects:
- Dyspepsia: upper abdominal pain, bloating, nausea
- 35% chronic NSAID users
- Ulcers
- 16 % chronic NSAID users
- Gastric more common than duodenal
- Risk factors:
- Greater than 65
- High dose
- Helicobacter pylori
- Alcohol consumption
GI Bleeding

Prevention of Adverse effects:
- H2 receptor antagonist
- Proton pump inhibitor
- MISOPROSTOL

13

Diclofenac

Nonselective COX inhibitor

Selectivity: 0.3
- Used in Rh ART

14

Diclofenac with Misoprostol

Nonselective COX inhibitor

Selective: 0.3
- Used in Rx arthritis and anti-inflammatory

15

Ibuprofen

Nonselective COX inhibitor

Selectivity: 2.6

16

Indomethacin

Nonselective COX inhibitor

Selectivity: 10

Used in Rx arthritis/anti-inflammatory

High frequency of intolerance

17

Ketorolac

Nonselective COX inhibitor

Selectivity: 395

Post-Surgical analgesic

18

Naproxen

Nonselective COX inhibitor

Selectivity: 3.8

OTC analgesic/antipyretic

May have a safe profile than other NSAIDS (besides aspirin)

Can be used in Rx anti-inflammatory

Naproxen may ha

19

Acetaminophen

Nonselective COX inhibitor

May be at risk for RENAL problems if taken
- Hepatotoxic at high doses

Activity is substantially reduced in presence of peroxides (often elevated at sites of inflammation)
- Lacks effects on platelets, cardiovascular, and GI system
- Analgesic and antipyretic effects equivalent to aspirin

20

Celecoxib

COX-2 Selective Inhibitor

10-20 more times selective for COX-2 over COX-1

Reduced incidence of GI effects

Remains available despite ADVERSE EFFECTS of incresed event of cardiovascular events
- HTN, MI, Stroke

21

Rofecoxib

COX-2 Selective NSAID

200 times more selective for COX-2 than COX-1

WITHDRAWN FROM THE MARKET