Question 1

Blocking which histamine receptor would help in the management of excessive gastric acid secretion?&#10;A) H1&#10;B) H2&#10;C) H3&#10;D) H4

Accepted Answer

Blocking H2 receptors helps in the management of excessive gastric acid secretion, as these receptors are involved in stimulating acid production in the stomach.

Question 2

First-generation antihistamines have a longer duration of action.

Accepted Answer

First-generation antihistamines typically have a shorter duration of action compared to second-generation antihistamines, requiring more frequent dosing.

Question 3

Where are H? receptors found?&#10;A) Stomach&#10;B) Smooth muscles&#10;C) Immune cells&#10;D) All of the above

Accepted Answer

H₁ receptors are found in various tissues including the stomach, smooth muscles, and immune cells. Therefore, the correct answer is D - all of the above.

Question 4

Which secondary messenger is associated with H? receptor activation?&#10;A) IP?&#10;B) Cyclic AMP&#10;C) DAG&#10;D) Both A and D

Accepted Answer

H₁ receptor activation is associated with the IP₃ secondary messenger.

Question 5

In comparison to second-generation antihistamines,first-generation antihistamines cause more:&#10;A) orthostasis.&#10;B) nausea.&#10;C) sedation.&#10;D) vomiting.

Accepted Answer

First-generation antihistamines are more likely to cause sedation, compared to second-generation antihistamines. Orthostasis, nausea, and vomiting are possible side effects of both first and second-generation antihistamines, but they are not necessarily more common in first-generation antihistamines.

Question 6

Which of the following mediators plays a role in modulating allergic reactions?&#10;A) Serotonin&#10;B) Histamine&#10;C) Pepsin&#10;D) None of the above

Accepted Answer

Histamine is a well-known mediator involved in modulating allergic reactions. It is released by mast cells and contributes to the symptoms of an allergic response such as itching, swelling, and bronchoconstriction. Serotonin and pepsin are not typically involved in allergic reactions.

Question 7

Which route of administration is preferred is hypovolaemic shock occurs?&#10;A) Intravenous&#10;B) Oral&#10;C) Rectal&#10;D) Transdermal

Accepted Answer

In hypovolemic shock, there is a decrease in blood volume and blood pressure, making it difficult for medications to be absorbed through other routes. Intravenous administration is the preferred route as it delivers the medication directly into the bloodstream, quickly increasing blood volume and pressure. Oral, rectal, and transdermal routes of administration may not be effective in this condition as they have a slower onset of action and may not be absorbed adequately.

Question 8

How many subtypes of H? receptors have been identified?&#10;A) Two&#10;B) Three&#10;C) Four&#10;D) Five

Accepted Answer

There are four known subtypes of histamine receptors: H1, H2, H3, and H4. However, H1 itself does not have subtypes; it is one of the four main types of histamine receptors.

Question 9

Antihistamines are used for the treatment of:&#10;A) allergies.&#10;B) anaphylactic reactions.&#10;C) depression.&#10;D) both A and B.

Accepted Answer

Antihistamines are primarily used for the treatment of allergies, such as allergic rhinitis, urticaria, and allergic conjunctivitis. They can also be used to treat anaphylactic reactions, which are severe and potentially life-threatening allergic reactions. Antihistamines are not used for the treatment of depression.

Deck 29: Histamine and Antihistamines