Sedative Hypnotics - II

Question 1

What are the 3 therapeutic uses of Phenothiazines?

Answer 1

1. Tranquilization
2. Pre-anesthetic
3. Anti-emetic

Question 2

What are the major pharmacological effects of Phenothiazines?

Answer 2

1. Sedation
2. Anti-histaminergic
3. Anti-arrhythmic
4. Anti-emetic

Question 3

What do Phenothiazines decrease when given at the therapeutic dose?

Answer 3

Decrease spontaneous motor activity and decrease aggressive behavior

Question 4

What do Phenothiazines cause at high doses?

Answer 4

1. Abolition of spontaneous locamotion
2. Cataleptic effects
3. Extrapyramidal symptoms (tremors, rigidity, akinesia)

Question 5

Which type of effects do Phenothiazines NOT produce?

Answer 5

Analgesic effects

Question 6

How do Phenothiazines cause antiemetic activity?

Answer 6

Via D2 receptor blockade in the medullary chemoreceptor trigger zone (CTZ)

Question 7

Phenothiazine administration should be avoided in ____ patients.

Answer 7

Hypovolemic

Question 8

Why should Phenothiazines be avoided in hypovolemic patients?

Answer 8

Risk of epinephrine reversal and hypotension

Question 9

In which patients should promethazine and trimeprazine NOT be used?

Answer 9

In animals undergoing skin tests for allergies, as these drugs block the H1 receptors

Question 10

When using Phenothiazines, you risk hypothermia. What are the 3 mechanisms by which this can occur?

Answer 10

1. Increased heat loss due to vasodilation
2. Decreased heat production due to lack of muscular activity
3. Depression of the thermoregulatory center in the hypothalamus