Question

Which one of the following is not true regarding use of the tricyclic antidepressants?

A. Owing to their ability to prolong cardiac conduction time their use in patients with conduction defects is contraindicated
B. These agents should be discontinued before elective surgery because they may cause hypertensive episodes during surgery
C. Some patients who experience orthostatic hypotension may respond to the use of fludrocortisone
D. Myoclonic twitches and tremors of the tongue and upper extremities are common in some patients on tricyclics
E. Amoxapine is the least likely to cause parkinsonian symptoms of all the tricyclics

Answer 1

The incorrect statement regarding the use of tricyclic antidepressants is that 'Amoxapine is the least likely to cause parkinsonian symptoms of all the tricyclics.' Tricyclics have various side effects and should be discontinued before surgery due to the risk of hypertension, but amoxapine can cause movement disorders, including parkinsonian symptoms.

Step-by-step explanation:

The statement regarding tricyclic antidepressants that is not true is: 'E. Amoxapine is the least likely to cause parkinsonian symptoms of all the tricyclics.' Tricyclic antidepressants, which include drugs like imipramine and amitriptyline, have structures that closely relate to phenothiazines but differ due to the ethylene group in imipramine's middle ring, which provides dissimilar stereochemical properties. While these drugs are effective in treating major depression, they can have a host of side effects, including the prolongation of cardiac conduction time and orthostatic hypotension. Fludrocortisone can help manage orthostatic hypotension in some patients. Regarding use before surgery, tricyclic antidepressants may indeed increase the risk of hypertension during surgery; hence, they should be discontinued prior to elective surgery.

However, contrary to the statement in option E, amoxapine can cause extrapyramidal symptoms, including parkinsonian ones, since it affects dopamine activity, a key aspect of the basal nuclei's chemistry involved in movement disorders.