Haloperidol respiratory

Patients in whom haloperidol is contraindicated can be treated by intramuscular injection of benzodiazepines, but these can cause respiratory depression or respiratory arrest if given in too high a dose, are contra-indicated in patients with preexisting respiratory depression, and have no specific anti-psychotic effect. 

A 35-year-old woman with schizophrenia developed acute respiratory distress and laryngeal stridor (196). Neuroleptic drug-induced laryngeal dystonia was diagnosed. She was given biperiden lactate 10 mg intramuscularly and her symptoms resolved fully within 30 minutes. On the advice of a psychiatrist, and to sedate her for admission to a psychiatric hospital, her mother had secretly put 50 drops of haloperidol (10 mg/ml) in her food 1 hour before the symptoms appeared. 

An 84-year-old Japanese woman with mixed dementia taking bromperidol and biperiden was switched to risperidone 2 mg/day. After several weeks she began to have limb and orofacial dyskinesia and staggered while walking. The risperidone was abruptly withdrawn. During the following days the previous abnormal movements increased and extended to the trunk. There was respiratory dyskinesia with dyspnea. The symptoms resolved completely in risperidone withdrawal and treatment with haloperidol and biperiden. 

Because of the frequency of co-administration of benzodiazepines with neuroleptic drugs, it is important to consider possible adverse effects that can result from such combinations. In a brief review, emphasis has been placed on pharmacokinetic interactions between neuroleptic drugs and benzodiazepines, as much information on their metabolic pathways is emerging (166). Thus, the enzyme CYP3A4, which plays a dominant role in the metabolism of benzodiazepines, also contributes to the metabolism of clozapine, haloperidol, and quetiapine, and neuroleptic drug plasma concentrations can rise. Intramuscular levomepromazine in combination with an intravenous benzodiazepine has been said to increase the risk of airways obstruction, on the basis of five cases of respiratory impairment the doses of levomepromazine were higher in the five cases that had accompanying airways obstruction than in another 95 patients who did not (167). 

In a randomized study in 301 agitated or aggressive patients, intramuscular midazolam was more rapidly sedating than a mixture of haloperidol + promethazine (12). There was only one important adverse event, transient respiratory depression, in one of the 151 patients who were given midazolam. 

The clinical effects of LSD ingestion are usually benign and require no medical intervention. However, panic attacks may be severe and require treatment with diazepam LSD-induced psychosis may be treated with haloperidol. Rare cases of massive overdose have resulted in life-threatening hyperthermia, rhabdomyolysis, acute renal failure, hepatic failure, DIG, respiratory arrest, and coma. Few if any well-documented deaths directly related to LSD ingestion have been reported. 

Occasional Akathisia rash fever arthralgia mania aminotransferase elevations abulia alopecia Rare Extrapyramidal reactions seizures in patients with preexisting seizure disorder leukocytosis bradycardia with syncope respiratory distress FLUPHENAZINE, see Phenothiazines, piperazine HALAZEPAM, see Benzodiazepines HALOPERIDOL... 

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