On the whole, cyclics are pretty safe and effective, falling somewhere between the MAOIs, which have many side effects, and SSRIs, which have very few. Even if you do run into some unpleasant side effects in the beginning, chances are they will become less of a problem as time goes by. If not, you can always switch to a drug with a different side-effect profile.
Side effects with cyclics may include dry mouth, constipation, blurred vision, weight gain, increased heart rate, drowsiness, urinary retention, impotence, decreased blood pressure, and dizziness when standing up. Those with the highest probability for these side effects include amitriptyline, clomipramine, doxepin, imipramine, and trimipramine. Desipramine has the lowest risk for these effects (see box "Potential Side Effects with Cyclic Antidepressants"). And patients taking high doses of cyclics often complain of memory problems and trouble in finding the right words.
And like every other antidepressant, cyclics can trigger a mild manic high in some people. In a retrospective study published in the British Medical Journal of 3,065 patients with major depression, tricyclics worsened suicidal thinking slightly more than Prozac did (16.3 percent compared with 15.3 percent). Suicidal acts were reported as 0.3 percent for Prozac and 0.4 percent for tricyclics.
About 15 percent of people may feel nauseated (compared with about 21 percent of people taking SSRIs); headaches occur in about 20 percent of people taking either SSRIs or tricyclics.
Because some of these drugs are known for sedative effects that cause drowsiness, dizziness, or decreased alertness, don't drive, fly an aircraft, operate dangerous machinery, or do anything requiring alertness until you learn how your medicine affects you.
Dry Mouth, Blurred Vision. As part of their action on many different brain systems, the cyclics act on histamine receptors, flicking on the body's "fight or flight" response, speeding up the heart, and shunting energy away from bodily functions, such as waste removal. The result is dry mouth, blurred vision, constipation, and urinary problems. These side effects may be especially annoying if you're taking amitriptyline, clomipramine, doxepin, imipramine, or protriptyline.