Similarity of Adverse Drug Reaction Patterns Among SSRIs

SIMILARITY OF ADVERSE DRUG REACTION PATTERNS AMONG SSRIs 

In general, the pattern of adverse reactions is similar among all the SSRIs and some of the other new antidepressants that block the reuptake of serotonin, especially venlafaxine. As a result, the FDA has required class label warnings for them in regard to suicidality and to the array of stimulant adverse reactions, from agitation and hostility to mania. 

A British study conducted on the basis of prescription-even monitoring (PEM) involved cohorts exceeding 10,000 patients for paroxetine, fluvoxamine, sertraline, and fluoxetine (Mackay et ah, 1997). The study confirmed the general similarity of reported adverse events, with two possible exceptions Fluvoxamine (Luvox) had an increased number of reported adverse events, and paroxetine (Paxil) had an increased number of reported withdrawal reactions. 

A Norwegian study by Olav Spigset utilizing that country s Adverse Drug Reactions Monitor Center reviewed 1,202 reports describing 1,861 adverse reactions to SSRIs. Again, the pattern of reports for the individual SSRIs (citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline) was very similar, with three exceptions. Fluvoxamine reports were comparatively elevated for gastrointestinal symptoms, fluoxetine 

SSRIs cause a wide range of neurological impairments. Spigset (1999) found the following neurological reports in order of frequency parethesias, headache, dizziness, tremor, seizures, acute dystonia, dyskinesia, muscle cramps, muscle weakness, parkinsonism, muscle stiffness, akathisia, myoclonus, extrapyramidal reactions, increased muscle tone, and migraine. There have been reports of irreversible tardive dyskinesia caused by SSRIs (see subsequent section). 

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