<p>Decreased antihypertensive effects of guanethidine, guanfacine, debrisoquine, betanidine and possibly clonidine. Increased CNS depression with CNS depressants such as alcohol, sedatives, hypnotics or barbiturates. Increased trimipramine levels with protease inhibitors, SSRIs, selegiline, tramadol, quinidine, diltiazem and verapamil. Decreased trimipramine levels with barbiturates. Increased risk of arrhythmias with drugs that prolong QT intervals. Increased risk of serotonin syndrome with linezolid. Increased antimuscarinic adverse effects with nefopam. Risk of neurotoxicity and serotonin syndrome with lithium.</p>