Selective serotonin reuptake inhibitors haloperidol

Patients seen for flashbacks are treated with oral diazepam (15—30 mg/day for adults) if symptoms of anxiety are severe (Rumack 1987). Neuroleptics, especially haloperidol, have been implicated in a transient increase in visual flashbacks and are not recommended (Moskowitz 1971 Strassman 1984). Risperidone and selective serotonin reuptake inhibitors may also worsen symptoms of hallucinogen persisting perception disorder (Halpern and Pope 2003). The patient needs assurance of the self-limiting nature of the phenomenon and its decreasing frequency of reoccurrence with time. The patient should be reminded that any future use of hallucinogens or marijuana may precipitate similar symptoms (Strassman 1984). 

There is, however, a unique risk in the bipolar form that antidepressant treatment may trigger a switch into mania. This may occur either as the natural outcome of recovery from depression or as a pharmacological effect of the drug. Particular antidepressants (the selective serotonin reuptake inhibitors) seem less liable to induce the switch into mania than other antidepressants or electroconvulsive therapy. Treatment for mania consists initially of antipsychotic medication, for instance the widely used haloperidol, often combined with other less specific sedative medication such as the benzodiazepines (lorazepam intramuscularly or diazepam orally). The manic state will usually begin to subside within hours and this improvement develops further over the next 2 weeks. If the patient remains disturbed with manic symptoms, additional treatment with a mood stabilizer may help. 

Side effects can also occur quickly after a single dose of a medication. For example, some antidepressants (e.g., selective serotonin reuptake inhibitors) can cause nausea, stomach upset, loose stools, and even diarrhea. Likewise, some anti-psychotics (e.g., haloperidol (Haldol)) can cause unpleasant or painful muscle spasms called dystonias. All of these side effects can occur within minutes or hours of taking a single dose of the medication. These side effects are also a result of the direct effects of the medication in the synapse. 

Haloperidol (Haldol), risperidone (Risperdal), loxapine (Loxitane), ziprasidone (Geodon), quetiapine (Seroquel), clozapine (Clozaril), aripiprazole (Abilify), and thioridazine (Mellaril) are targeted in this solid phase extraction (SPE), liquid chromatography— tandem mass spectrometry (LC-MS/MS) method. Both 9-hydroxy-risperidone (Paliperiodone), an equipotent metabolite, and mesoridazine (Serentil) are also included in this method as they are pharmacologically active major metabolites of risperidone and thioridazine, respectively (4). Olanzapine (Zyprexa) can be quantified with this instrument method however, the extraction method is a liquid-liquid basic extraction (see Note 1). Due to the subsequent administration of antidepressants in conjunction with antipsychot-ics, this method can also be used for many of the common antidepressants, including the selective serotonin reuptake inhibitors (SSRIs) (see Note 2). 

There are several antipsychotics that are substrates to CYP2D6 (von Bahr et ah, 1991 Jerling et ah, 1996 Ring et ah, 1996 (Fang and Gorrod, 1999 Flockhart and Oesterheld, 2000) (Table 26.3). Moreover, several antipsychotics may act as inhibitors of CYP2D6-mediated biotransformation. These include thioridazine, chlorpromazine, haloperidol, fluphenazine, and pimozide (Desta et ah, 1998 Shin et ah, 1999). Of particular salience is the fact that the serotonin selective reuptake inhibitors (SSRIs) fluoxetine and paroxetine are metabolized to a significant extent by this isoenzyme. 

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