The initial doses of chlorprothixene should be as low as possible (e.g. 30mg at bedtime, 15mg morning dose) and be increased gradually. Patients receiving 90mg daily (and more) of the drug should be hospitalized, particularly during the initial phase of treatment. If chlorprothixene is to be withdrawn, it should not be stopped abruptly, but the dose should be decreased steadily.
Chlorprothixene may increase the plasma-level of concomitantly given lithium. In order to avoid lithium intoxication, lithium plasma levels should be monitored closely. If chlorprothixene is given concomitantly with opioids, the opioid dose should be reduced (by approx. 50%), because chlorprothixene amplifies the therapeutic actions and side-effects of opioids massively. Avoid the concomitant use of chlorprothixene and tramadol (Ultram). Massive seizures may be encountered with this combination. Consider additive sedative effects and confusional states to emerge, if chlorprothixene is given with benzodiazepines or barbituates. Choose particular low doses of these drugs. Exert particular caution in combining chlorprothixene with other anticholinergic drugs (tricyclic antidepressants and antiparkinsonian agents): Particularly the elderly may develop delirium, high fever, severe obstipation, even ileus and glaucoma.
Contraindications include alcohol abuse (adds to the central nervous system (CNS) depressant effects), blood disease, enlarged prostate, glaucoma, heart or blood vessel disease, lung disease, Parkinsons disease, stomach ulcers, urination problems (thioxanthenes may worsen the condition), liver disease (higher blood levels of thioxanthenes may occur, increasing the likelihood of side effects), Reyes syndrome (the risk of liver problems may be increased), and seizure disorders (the risk of seizures may be increased).