SSRIs agitation caused

Newer antidepressants (eg, fluoxetine, paroxetine, citalopram, venlafaxine) are mostly SSRIs and are generally safer than the tricyclic antidepressants and monoamine oxidase inhibitors, although they can cause seizures. Bupropion (not an SSRI) has caused seizures even in therapeutic doses. Some antidepressants have been associated with QT prolongation and torsade de pointes arrhythmia. SSRIs may interact with each other or especially with monoamine oxidase inhibitors to cause the serotonin syndrome, characterized by agitation, muscle hyperactivity, and hyperthermia (see Chapter 16). 

Discontinuation of SSRIs can cause adverse events including dizziness, insomnia, nervousness, nausea, and agitation. See Discontinuation Syndrome under the section Human Toxicology (Acute) for more information. 

Adverse Effects. Typical antidepressant doses of SSRIs can cause side effects of insomnia, jitteriness, restlessness, and agitation, and lead to drug discontinuation in patients with panic disorder. Transient gastrointestinal disturbances occur more frequently with SSRIs than with TCAs. Thus low initial SSRI doses should be prescribed. Sleep disturbances, headaches, and sexual dysfunction often are problematic. ... 

Uses Obesity Action Blocks uptake of norepinephrine, serotonin, dopamine Dose 10 mg/d PO, may to 5 mg after 4 wk Caution [C, -] w/ SSRIs, Li, dextromethorphan, opioids Contra MAOI w/in 14 d, uncontrolled HTN, arrhythmias Disp Caps SE HA, insomnia, xerostomia, constipation, rhinitis, tach, HTN Interactions T Risk of serotonin synd W/ dextromethorphan, ergots, fentanyl, Li, meperidine, MAOIs, naratriptan, pentazocine, rizatriptan, sumatriptan, SSRIs, tryptophan, zolmitriptan, St. John s wort effects W/ cimetidine, erythromycin, ketoconazole T CNS depression W/ EtOH EMS Use fentanyl w/ caution, may T risk of serotonin synd concurrent EtOH use can T CNS depression OD May cause tach, HTN, diaphoresis, HA, fever, agitation, muscle tremors, and Szs symptomatic and supportive... 

Ebert et al. (1997) attempted to develop a rate estimate for severe mental aberrations caused by fluvoxamine. They carried out a prospective study of 200 inpatients over a total of 8,200 treatment days with the SSRI. Fourteen patients (17%) developed hypomania according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV APA, 1994) criteria. Three patients (1.5%) developed insomnia, agitation, confusion,... 

Venlafaxine (Effexor), approved by the FDA in December 1993, was described in more detail early in this chapter. It is one of the newer antidepressants implicated in causing suicidality. It is a NSRI that also strongly inhibits the reuptake of epinephrine. Its profile is very similar to the SSRIs in producing stimulation, including anxiety, nervousness, insomnia, anorexia, and weight loss. It causes the various emotional and behavioral abnormalities that go along with stimulation, such as agitation and mania, and has been associated with hostility, paranoid reaction, psychotic depression, and psychosis. It can cause hypertension. 

When ceasing use of an antidepressant, the dose should be reduced over at least 6 weeks to avoid a discontinuation syndrome (symptoms include anxiety, agitation, nausea and mood swings). Discontinuation of SSRIs and venlafaxine are associated additionally with dizziness, electric shocklike sensations and paraesthesia. Short-acting drugs that do not produce active metabolites are most likely to cause such problems. Paroxetine in particular is associated with severe withdrawal symptoms including bad dreams, paraesthesia and dizziness (which can be misdiagnosed as labyrinthitis). 

Figure 3.2 Like TCAs, SSRIs have a high probability of causing sexual dysfunction. Other side effects, listed here, include agitation, insomnia, and sedation, although they occur less frequently.

Very serious problems can arise if Effexor is taken with MAOIs. This is due to the serotonin syndrome, also mentioned in Chapter 2, which is a reaction caused by overstimulation of serotonin receptors. Since Effexor, like SSRIs, increases serotonin availability while MAOIs decrease serotonin breakdown, the additive levels of serotonin can cause severe behavioral reactions, such as confusion, agitation, and increased aggression, as well as extreme sweating and tremor. 

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