Haloperidol intramuscular

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. 

Figure 3.1 Maximal haloperidol concentration after 0.5 mg intramuscular haloperidol...

Intramuscular (IM) Into skeletal muscle. This route is used to deliver depot antipsychotic drugs like fluphenazine and haloperidol decanoate, which are used in the treatment of schizophrenia. 

The medication of choice was for many years haloperidol (Haldol), a high potency antipsychotic, that can be given orally or by injection. When used, haloperidol should be administered in low doses (0.5-1.0mg) and only on an as-needed basis. Due to concerns regarding the tolerability of haloperidol in patients with dementia, its role in the management of agitation associated with delirium has largely been supplanted by atypical antipsychotics. A number of atypical antipsy-chotics are available by either an oral or intramuscular (injection) route of administiation. 

When esterified with a fatty acid, both fluphenazine and haloperidol can be applied intramuscularly as depot preparations. 

Intramuscular haloperidol is a suitable drug for tranquillizing violent patients, but it can be difficult to determine the correct dosage, and there is the risk of an acute dystonic reaction, particularly in younger patients. The British National Formulary recommends intramuscular injections of from 2 to 10 mg, subsequent doses being given after 4-8 hours but in exceptional cases, initial doses of up to 30 mg may be necessary. 

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. 

Breier A, Meehan K, Birkett M, et al A double-blind, placebo-controlled dose-response comparison of intramuscular olanzapine and haloperidol in the treatment of acute agitation in schizophrenia. Arch Gen Psychiatry 59 441 48, 2002... 

The intramuscular administration of antipsychotics acting for weeks prevents this independent action and improves compliance on the other hand, only highly potent antipsychotics such as fluphenazine, flupenthixol and haloperidol are suitable for depot administration and it is precisely these medicines that lead more frequently to EPS and dysphoric mood (van Putten et al, 1984). 

Nair NPV, Suranyi-Cadotte B, Schwartz G, et al. A clinical trial comparing intramuscular haloperidol decanoate and oral haloperidol in chronic schizophrenic patients efficacy, safety, and dosage equivalence. J Clin Psychopharmacol 1986 6(suppl 1) 30S-37S. 

Deberdt R, Elens P, Berghmans W, et al. Intramuscular haloperidol decanoate for neuroleptic maintenance therapy. Efficacy, dosage schedule and plasma levels. An open multicenter study. 

The neuroleptics show variable absorption after oral administration. These agents readily pass into the brain, have a large volume of distribution, bind well to plasma proteins, and are metabolized to many different substances by the P-450 system in the liver. Fluphenazine decanoate and haloperidol decanoate are slow release (up to 3 weeks) formulations of neuroleptics, administered by intramuscular injection. These drugs are increasingly used in treating outpatients and individuals who are noncompliant. However, about 30% of these patients develop extrapyramidal symptoms. The neuroleptic drugs produce some tolerance but little physical dependence. 

In a double-blind, placebo-controlled, dose-response trial, 270 acutely agitated patients were randomized to receive 1-3 intramuscular injections of olanzapine (2.5, 5, 7.5, or 10 mg), haloperidol (7.5 mg), or placebo within 24 hours (60). Olanzapine had a dose-related effect in reducing agitation olanzapine was better than placebo but not better than haloperidol the most frequently reported adverse event was hypotension, which occurred with olanzapine (n = 7) but not haloperidol or placebo. Acute dystonias did not occur in patients given olanzapine or placebo but occurred in two patients given haloperidol. 

Intramuscular ziprasidone has recently been compared with intramuscular haloperidol in the treatment of acute psychosis for a very short period (83). Patients were randomly allocated to intramuscular ziprasidone for up to 3... 

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. 

There have been reports of neuroleptic malignant syndrome precipitated by promethazine 100 mg/day to treat neuroleptic drug-induced extrapyramidal symptoms and lorazepam 6 mg/day to treat agitation (349), after the addition of intramuscular haloperidol 23 mg to atypical neuroleptic drugs (350), and in other instances in children and adolescents (351). 

A 19-year-old man with bipolar disorder received intramuscular haloperidol 30 mg/day and chlorproma-zine 300 mg/day and developed neuroleptic malignant syndrome the neuroleptic drugs were withdrawn. One month later he had a recurrence. It transpired that he had discontinued his medication 2 weeks after discharge, but because his manic symptoms recurred his relatives had started to give him haloperidol 10 mg/day again, which led to the recurrence. 

A 38-year-old woman was admitted to hospital in the third week after conception and acute schizophrenia was diagnosed. She was given oral haloperidol 1.5 mg at 12-hourly intervals. In the fourth week after conception, intramuscular depot fluphenazine 12.5 was added every 15 days. At 8 weeks of gestation, after the pregnancy had been diagnosed, haloperidol and fluphenazine were withdrawn and trifluoperazine 5 mg was started and continued until 8 weeks before the baby was bom. The child was bom with phocomelia of the left arm, with an extremely short humerus and an absent forearm. 

Brook S, Lucey JV, Gunn KP. Intramuscular ziprasidone compared with intramuscular haloperidol in the treatment of acute psychosis. Ziprasidone I.M. Study Group. J Clin Psychiatry 2000 61(12) 933-41. 

Asystolic cardiac arrest occurred in a 49-year-old woman after she had received haloperidol 10 mg intramuscularly for 2 days no previous QTC prolongation had been observed (16). 

Brook S, Walden J, Benattia I, Siu CO, Romano SJ. Ziprasidone and haloperidol in the treatment of acute exacerbation of schizophrenia and schizoaffective disorder comparison of intramuscular and oral formulations in a 6-week, randomized, blinded-assessment study. Psychopharmacology 2005 178 514-23. 

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). 

Intramuscular lorazepam 4 mg has been compared with the combination of intramuscular haloperidol 10 mg + promethazine 50 mg in 200 emergency psychiatric patients with agitation, aggression, or violence (2). The treatments were comparably effective and well tolerated overall, but two patients who took lorazepam had moderate adverse effects one had worse bronchial asthma and one had nausea and dizziness. 

Alexander J, Tharyan P, Adams C, John T, Mol C, Philip J. Rapid tranquillisation of violent or agitated patients in a psychiatric emergency setting. Pragmatic randomised trial of intramuscular lorazepam v. haloperidol plus promethazine. Br J Psychiatry 2004 185 63-9. 

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. 

Intramuscular injection Haloperidol, ziprasidone, olanzapine Maximum blood levels achieved in a short period of time... 

Haloperidol s long-acting intramuscular formulation lasts up to 4 weeks, whereas some other long-acting intramuscular antipsychotics may only last up to 2 weeks... 

Intramuscular loxapine may have faster onset of action and superior efficacy for agitated/excited and aggressive behavior in some patients than intramuscular haloperidol... 

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