Haloperidol SSRIs

CYP2D6 TCAs, SSRIs, haloperidol, mirtazepine, zuclopenthoxil, venlafaxine, sertraline CYP2C19 TCAs, mephenytoin, diazepam, moclobemid, venlafaxine... 

The key has been to avoid using treatments that worsen the disease. In this instance, this means avoiding anticholinergic (acetylcholine-blocking) medications that worsen dementia. As a result, when newer antidepressants such as the SSRIs became available, they quickly replaced the older tricyclic antidepressants because the latter are potent anticholinergics. For the same reason, the low potency anti-psychotics like chlorpromazine (Thorazine) were replaced by the higher potency antipsychotics like haloperidol (Flaldol) and more recently by the atypical antipsychotics. 

Agitation (chronic) Sodium divalproex Risperidone Olanzapine SSRI Trazodone Ziprasidone Haloperidol... 

Chronic Agitation. For chronic agitation with physical aggression, sodium divalproex is the preferred treatment. If divalproex is ineffective, haloperidol or an atypical antipsychotic can be added or snbstituted. Other options include trazodone, carbamazepine, and SSRI antidepressants. 

Drugs that may affect beta blockers include aluminum salts, barbiturates, calcium salts, cholestyramine, cimetidine, colestipol, diphenhydramine, hydroxychloroquine, NSAIDs, penicillins (ampicillin), rifampin, salicylates, SSRIs, sulfinpyrazole, calcium blockers, oral contraceptives, flecainide, haloperidol, hydralazine, loop diuretics,... 

Drugs that may be affected by SSRIs Drugs that may be affected by SSRIs include alcohol, benzodiazepines, beta blockers, buspirone, carbamazepine, cisapride, clozapine, cyclosporine, diltiazem, digoxin, haloperidol, hydantoins, lithium, methadone, mexiletine, nonsedating antihistamines, NSAIDs, olanzapine, phenothiazines, phenytoin, pimozide, procyclidine, ritonavir, ropivacaine, sumatriptan, sulfonylureas, sympathomimetics, tacrine, theophylline, tolbutamide, tricyclic antidepressants, and warfarin. 

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. 

Studies of the use of the specific serotonin-uptake inhibitors (SSRIs) to treat OCD suggest that, compared to non-tic-related OCD, tic-related OCD is less responsive to SSRI monotherapy (McDougle et al., 1993, 1994). Addition of a neuroleptic, such as haloperidol (McDougle et ah, 1994), risperidone (McDougle et al., 2000), or olanzapine (Bogetto et al., 2000), appears to be useful in improving treatment-resistant individuals response to a SSRI. It is unclear whether this pattern of treatment response is specifically associated with a comorbid tic disorder the pattern of obsessive compulsive symptoms characteristic of TS or yet some other predictors. 

In most cases, SSRIs are the first choice for drugs to combat OCD. Clomipramine, fluvoxamine, fluoxetine, paroxetine, sertraline, and citalopram are all SSRIs that have been proven effective in reducing OCD symptoms. However, in about 40 to 60% of patients, these drugs do not completely alleviate all the symptoms. When this is the case, a second type of drug called a neuroleptic is often added. Neuroleptic drugs, such as haloperidol, clozapine, risperidone, and chlorpromazine... 

ARIPIPRAZOLE, CLOZAPINE, HALOPERIDOL, PERPHENAZINE, RISPERIDONE, SERTINDOLE SSRIs Possible t plasma concentrations of these antipsychotics Inhibition of CYP2D6-mediated metabolism of these drugs. The clinical significance of this depends upon whether alternative pathways of metabolism of these substrates are also inhibited by co-adminis-tered drugs. The risk is theoretically greater with clozapine, haloperidol and olanzapine because their CYPl A2-mediated metabolism Is also Inhibited by SSRIs Warn patients to report T side-effects of these drugs, and consider reducing the dose of the antipsychotic... 

On the whole no significant adverse interactions appear to occur between the antipsychotics and the SSRIs. However, a number of case reports describe extrapyramidal adverse effects following the use of fluoxetine or paroxetine with an antipsychotic, and ga-lactorrhoea and amenorrhoea developed in one patient given loxapine and fluvoxamine. Fluoxetine and fluvoxamine appear to raise haloperidol levels, which may increase adverse effects. Thioridazine levels are expected to be increased with fluoxetine, fluvoxamine, or paroxetine treatment with a risk of QT interval prolongation. 

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