16 - 20 Pharmacology SBAs for the Primary FRCA
Question 16
Prochlorperazine and chlorpromazine are both phenothiazines.
Which of the following is true regarding phenothiazines?
- They are atypical antipsychotics
- They are dopamine agonists
- They have a three ring structure
- They can induce bronchospasm
- They don't affect the chemoreceptor trigger zone
Answer
- They have a three ring structure
All of the phenothiazines (also called typical antipsychotics) have a three ring structure, and it's their side chains that give them their distinct pharmacological characteristics.
They're generally classed as dopamine antagonists and are associated with extrapyramidal side effects.
They tend to induce bronchodilation via their antimuscarinic effects.
Prochlorperazine and Chlorpromazine both have useful anti-emetic effects via the CTZ.