Chlorpromazine Valproate

Plasma levels of valproate may also be Increased by felbamate, chlorpromazine, fluoxetine, fluvoxamine, topiramate, cimetidine, erythromycin, and ibuprofen... 

Hiccup (due to diaphragmatic spasm). Where this is intractable and exhausting, chlorpromazine (or other phenothiazine) or metoclopramide may help also baclofen, nifedipine or sodium valproate. 

Recently a hyperactivity model induced by a combination of D-amphetamine and chlordiazepoxide was studied. Lamotrig-ine, valproate, and carbamazepine, all used to treat bipolar disorder, were all found to decrease this hyperactivity (Arban et al., 2005). Interestingly, while most mania models assume an increase in dopamine, an early model used dopamine depletion with intracerebroventricular injection of 6-hydroxydopa-mine, which induces hyper-reactivity to environmental stimuli, but not hyperactivity per se (Petty and Sherman, 1981). This model was responsive to chronic hthium and to chronic electroconvulsive shock, and also to acute chlorpromazine, while imipramine worsened the behavior. 

Chlorpromazine Phenobarbital Phenytoin Valproate Probably of little clinical relevance for phenytoin, a fall in concentration has also been reported Inhibition of metabolism of the object drugs... 

Valproate serum levels are slightly raised in patients given chlorpromazine, but this appears to be of minimal clinical importance. An isolated report describes severe hepatotoxicity on concurrent use. 

Bach N, Thung SN, Schaffner F, Tobias H. Exaggerated cholestasis and hepatic fibrosis following simultaneous administration of chlorpromazine and sodium valproate. Dig Dis Sci (1989)34, 1303-7. 

Haloperidol plasma levels are roughly halved by carbamazepine, phenobarbital and phenytoin. Bromperidol, fluphenazine and ti-otixene levels are also reduced by carbamazepine. The plasma levels of chlorpromazine and haloperidol do not appear to be affected by oxcarbazepine. Neurotoxicity has been seen with haloperidol and carbamazepine and haloperidol can raise serum carbamazepine levels. Valproate or valproic acid appear not to interact. 

A study in 6 patients given haloperidol 6 to 10 mg daily found no significant interaction with valproic acid. Similarly, haloperidol was not found to interact with valproate in two further studies, although in one of these studies an increase of 64% in haloperidol plasma levels was seen, which was considered not significant. For the interaction of valproic acid with chlorpromazine, see Valproate + Chlorpromazine , p.577. 

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