Histamines And Antihistamines Question And Answers

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Histamines And Antihistamines Important Notes

1. Antihistamines

Histamines And Antihistamines Antihistamines

  • Antihistamines Uses
    • Common cold
    • Anti-allergic
    • Insect bite
    • Idiopathic pruritis
    • Motion sickness
    • Vertigo

Read And Learn More: Pharmacology Question and Answers

Histamines And Antihistamines Short Essays

Question 1. Mention four newer antihistamines with their advantages.
Answer:

  • Newer Antihistamines are:
    • Fexofenadine
    • Loratadine
    • Cetrizine
    • Azelastine
    • Mizolastine
    • Terfenadine

Newer Antihistamines Advantages:

  • Donot impair psychomotor performance
  • Produce no subjective effects
  • No sedation as they poorly cross the blood-brain barrier
  • No anticholinergic side effects

Question 2. Mention four therapeutic uses of HI blockers.
Answer:

Uses of H1 Blockers:

1. Allergic reactions

    • Block the effects of released histamine
    • Control Immediate types of allergies like Itching, urticaria, angioedema
    • Cetrizine has an adjuvant role In seasonal asthma

2. Prurltldes

    • Older H1 blockers are used In Idiopathic pruritus

3. Common cold

    • Provide symptomatic relief by anticholinergic and sedative actions

4. Motion sickness

    • Promethazine and diphenhydramine are used prophylactically in motion sickness
    • It should be taken one hour before the journey

5. Vertigo

    • Inhibits vestibular sensory nuclei in the inner ear

6. Preanasethetic medication

    • Promethazine is used for it
  • It includes the following groups

Histamines And Antihistamines Preanasethetic Medication It Includes Following Groups

7. Cough

    • Provide symptomatic relief

8. Parklsonism

    • Provide symptomatic relief

9. Acute muscle dystonia

    • Due to Its central anticholinergic action

10. As sedative, hypnotic, and anxiolytic

Question 3. Autocoids
Answer:

  • Autocoids are substances formed in various tissues, have complex physiological and pathological actions, and act locally at the site of synthesis
  • They are called local hormones
  • They serve as transmitters or moderators in the nervous system
  • They have brief action and are destroyed locally

Question 4. Antihistamines
Answer:

  • Antihistamines are the drugs that competitively antagonize the action of histamine at H1 receptors

Antihistamines Classification

Histamines And Antihistamines Antihistamines Classification

Antihistamines Uses:

  • Allergic disorders
  • Priorities
  • Common cold
  • Cough
  • Motion sickness
  • Preanasethetic medication
  • Vertigo
  • Parkinsonism
  • Acute muscle dystonia
  • As sedative, hypnotic, anxiolytic
  • To control mild blood transfusion and saline infusion reactions

Question 5. Enumerate two nonsedative Antihistamines and mention four uses of them.
Answer:

Non Sedative Antihistamines:

  • Fexofenadine
  • Loratadine
  • Cetrizine
  • Azelastine
  • Mizolastine
  • Terfenadine

Non Sedative Antihistamines Uses:

  • Allergic rhinitis, conjunctivitis, hay fever
  • Control sneezing and runny nose, red watering eyes
  • Urticaria, dermographism, atopic eczema
  • Acute allergic reactions to drugs and food

Histamines And Antihistamines Short Question And Answers

Question 1. Cyproheptadine
Answer:

Cyproheptadine is a serotonin antagonist

Cyproheptadine Actions:

  • Blocks 5-HT2
  • Blocks H1 receptors
  • Blocks cholinergic receptors
  • Increases appetite

Cyproheptadine Uses:

  • Promote weight gain in children and poor eaters
  • To control intestinal manifestations of carcinoid tumors

Question 2. Non sedative Antihistamines
Answer:

Non Sedative Antihistamines:

  • Fexofenadine
  • Loratadine
  • Cetrizine
  • Azelastine
  • Mizolastine
  • Terfenadine

Non Sedative Antihistamines Uses:

  • Allergic rhinitis, conjunctivitis, hay fever
  • Control sneezing and runny nose, red watering eyes
  • Urticaria, dermographism, atopic eczema
  • Acute allergic reactions to drugs and food

Non-Sedative Antihistamines Advantages:

  • Donot impair psychomotor performance
  • Produce no subjective effects
  • No sedation as they poorly cross the blood-brain barrier
  • No anticholinergic side effects

Question 3. Cetrizine
Answer:

  • Cetrizine is non sedative Antihistamines
  • It can metabolite of hydroxyzine with a marked affinity for peripheral H1 receptors
  • It is well absorbed orally
  • It attains high and long-lasting concentration in the skin

Cetrizine Actions:

  • Inhibits the release of histamine and cytotoxic mediators from platelets
  • Inhibits Eosinophil chemotaxis during the secondary phase of the allergic response

Cetrizine Uses:

  • Upper respiratory allergies, pollinosis, Urticaria, atopic dermatitis
  • Adjuvant to seasonal asthma

Question 4. Ergometrine
Answer:

  • Ergometrine is an amine ergot alkaloid
  • It is a very weak Agonist
  • It has no antagonist action on alpha-adrenergic receptors
  • The emetic potential is low
  • They are rapidly and completely absorbed
  • The plasma half-life is 1-2 hours
  • Onset of action

Histamines And Antihistamines Onset Of Action

Ergometrine Uses:

  • To control and prevent postpartum hemorrhage
  • To prevent uterine atony
  • To ensure normal involution

Question 5. Promethazine
Answer:

  • Promethazine is a highly sedative H1 antagonist

Promethazine Uses:

  • Allergic disorders
  • Pruritis
  • Common cold
  • Preanasethetic medication
  • Parkinsonism

Question 6. Prostaglandins
Answer:

  • Prostaglandins are biologically active derivatives of 200-carbon atom polyunsaturated fatty acids
  • They are major lipid-derived autocoids

Prostaglandins Actions:

Histamines And Antihistamines Prostaglandins Actions

Question 7. Uses of ergot alkaloids
Answer:

Histamines And Antihistamines Uses Of Ergot Alkaloids

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