Escitalopram toxicity

The most common interactions with SSRIs are pharmacokinetic interactions. For example, paroxetine and fluoxetine are potent CYP2D6 inhibitors (Table 30-4). Thus, administration with 2D6 substrates such as TCAs can lead to dramatic and sometimes unpredictable elevations in the tricyclic drug concentration. The result may be toxicity from the TCA. Similarly, fluvoxamine, a CYP3A4 inhibitor, may elevate the levels of concurrently administered substrates for this enzyme such as diltiazem and induce bradycardia or hypotension. Other SSRIs, such as citalopram and escitalopram, are relatively free of pharmacokinetic interactions. The most serious interaction with the SSRIs are pharmacodynamic interactions with MAOIs that produce a serotonin syndrome (see below). 

ESCITALOPRAM, FLUOXETINE, FLUVOXAMINE, PAROXETINE, SERTRALINE BUPROPION T plasma concentrations of these SSRIs, with risk of toxic effects Bupropion and its metabolite hydroxybupropion inhibit CYP2D6 Initiate therapy of these drugs at the lowest effective dose. Interaction is likely to be important with substrates for which CYP2D6 is considered the only metabolic pathway (e.g. paroxetine)... 

Ingestion-. Nausea, vomiting, abdominal pain, diarrhea, tremor, confusion, agitation, drowsiness, insomnia, flulike syndromes, blurred vision, and in rare cases, seizures and coma. Significant cardiovascular toxicity is unusual (except with citalopram). Effects include mild hypo- or hypertension, tachycardia, and ventricular dysrhythmia. Escitalopram also has been shown to cause dermatologic, gastrointestinal, sexual, respiratory, and other miscellaneous adverse reactions. 

There is an increased risk of central nervous system toxicity when escitalopram is combined with sumatriptan. - ... 

Many noncyclic antidepressants are now available, including trazodone (Desyrel l), nefazodone (Serzone ), fluoxetine (Prozac ), sertraline (Zolotf ), citalopram (Celexa ), escitalopram (Lexapro ), paroxetine (Paxil ), tluvoxamine (Luvox ), venlafaxine (Effexor ), and bupropion (Wellbutrin ). Bupropion is also marketed under the brand name Zyban tor smoking cessation. Mirtazapine (Remeron ), a tetracyclic antidepressant, has recently become available. In general, these drugs are much less toxic than the tricyclic antidepressants (see p 90) and the monoamine oxidase (MAO) inhibitors (p 269), although serious effects such as seizures and hypotension occasionally occur. Noncyclic and tricyclic antidepressants are described in Table 11-7. 

Fluoxetine, paroxetine, sertraline and possibly citalopram can raise serum clozapine levels. Escitalopram is predicted to interact similarly. Particularly lai e increases in clozapine levels can occur with fluvoxamine. Clozapine toxicity has been seen in some patients. 

A report describes a 74-year-old woman with increased lithium levels of 2.3 mmol/L and symptoms of lithium toxicity, which were associated with several drugs including irbesartan, lisinopril, escitalopram, levomepro-mazine, furosemide and spironolactone. It was suggested that these drugs could have delayed lithium excretion or worsened neurotoxic effects. An increase in the lisinopril dose and the addition of irbesartan several weeks before admission may have contributed to the lithium toxicity. ... 

---