Treatment of depression. New pharmacologic approaches

Recurrent major depression is an underdiagnosed, undertreated mood disorder that affects approximately 10 million Americans. Although the tricyclic antidepressants are the oldest and best studied class of antidepressant medications available, their use is routinely compromised by unsatisfactory pharmacokinetic and side-effect profiles. The newer antidepressant medications have longer half-lives and are less likely to produce side effects. The prototypes of the newer antidepressants are bupropion (Wellbutrin) and fluoxetine (Prozac). Fluoxetine distinguishes itself in that its half-life is 2 to 3 days, whereas the mean half-life of buproprion and the tricyclics are 10 to 14 hours. For this reason, fluoxetine is routinely administered once daily in the morning. Both of these agents bind to the cholinergic, histaminergic, and alpha-1 adrenergic receptors with minimal affinity, and are less likely to yield clinically significant side effects. The use of the newer antidepressants has led to improved patient compliance and physician acceptance.