Chlorphenamine

Question 1

Class

Answer 1

Antiallergenic

Question 2

Classification

Answer 2

Antihistamine

Question 3

Actions

Answer 3

Blocks effects of histamine

Question 4

Indication

Answer 4

• severe anaphylaxis

- symptomatic allergic reactions (hay fever, urticaria, food allergy, relief from itch associated chicken pox)

Question 5

Caution

Answer 5

• Sedation/drowsiness
• children and elderly more susceptible to side effects
• anti-cholinergic actions resulting in urinary retention in prostatic disease or hypotension
• caution when association with Glaucoma, Epilepsy or Hepatic Disease

Question 6

Adverse Effects

Answer 6

• Sedation and drowsiness
• anti muscarinic effects (anti cholinergic) - dry mouth and blurred vision
• GI disturbance
• convulsions (rare)

Question 7

Presentation

Answer 7

• 10mg in 1ml for IV/IO
• 4mg tablet (per os)
• oral solution 2mg/5ml

Question 8

Pharmacodynamics

Answer 8

• no influence on release of histamine from mast cell
• causes vasodilation, hypotension, pruritic and bronchoconstriction when histamine binds with H1 receptor
• binds with and blocks histamine receptor (H1)
• antagonistic effect on cholinergic nervous system

Question 9

Pharmacokinetics

Answer 9

• Absorption: Introduced via IV/IO or PO routes. Well absorbed via GI tract.
• Distribution: protein binding 72%, passes easily across blood brain barrier
• Metabolism: primarily via hepatic system. Half life of 21-27 hours
• Elimination: Unsure