Bupropion should be considered for patients who cannot tolerate the adverse effects of SSRIs, but only after therapeutic trials of at least two different SSRIs. Bupropion can lower seizure threshold and should be avoided in patients who have a history of seizure disorder. The usefulness of these agents as first line therapy in primary care is limited because of their adverse effects. Dry mouth, constipation, urinary retention, and sedation present difficulties for most patients and may lead to noncompliance. More severe adverse effects, such as arrhythmias and orthostatic hypotension, particularly limit their usefulness in the elderly.
Tricyclic antidepressants have a narrow therapeutic index, and overdoses can be life-threatening.
Monitoring of the serum concentration can aid in minimizing adverse effects and ensuring optimal dosing. Considerations in selecting antidepressants Both drug and patient related factors should be considered when selecting an antidepressant. Drug related factors include adverse effect profile, long term tolerability, cost, and drug interactions. Antidepressants cannot be differentiated on the basis of effectiveness but, rather, on the basis of safety. The advantage of the newer SSRIs and heterocyclic antidepressants is that they offer improved adverse-effect profiles compared with the tricyclic antidepressants and monoamine oxidase inhibitors.