1 Adverse Reaction Overview, Tardive Dyskinesia). A syndrome consisting of potentially irreversible, involuntary, dyskinetic movements may develop in patients treated with conventional antipsychotic drugs. Although the prevalence of tardive dyskinesia with conventional antipsychotics appears to be highest among the elderly, especially elderly women, it is impossible to rely upon prevalence estimates to predict, at the beginning of treatment, which patients are likely to develop the syndrome.
XYLAC (loxapine) Page 11 of 36 Both the risk of developing tardive dyskinesia and the likelihood that it will become irreversible are believed to increase as the duration of treatment and the total cumulative dose of antipsychotic drugs administered to the patient increase.
However, the syndrome can develop, although much less commonly, after relatively brief treatment periods at low doses. There is no known treatment for established cases of tardive dyskinesia, although the syndrome may remit, partially or completely, if antipsychotic drug treatment is withdrawn.
Antipsychotic drug treatment itself, however, may suppress (or partially suppress) the signs and symptoms of tardive dyskinesia and thereby may possibly mask the underlying process. The effect that symptom suppression has upon the long-term course of the syndrome is unknown.
Given this consideration, XYLAC should be prescribed in a manner that is most likely to minimize the risk of the occurrence of tardive dyskinesia. As with any antipsychotic drug, chronic XYLAC use should be reserved for patients who appear to be obtaining substantial benefit from the drug.
In such patients, the smallest dose and the shortest duration of treatment should be sought. The need for continued treatment should be reassessed periodically. If signs and symptoms of tardive dyskinesia appear in a patient on XYLAC, drug discontinuation should be considered.
However, some patients may require treatment with XYLAC despite the presence of the syndrome.
Neuroleptic Malignant Syndrome (NMS):
A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association with antipsychotic drugs including XYLAC. Clinical manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmias).
Additional signs may include elevated creatine phosphokinase, myoglobinuria (rhabdomyolysis), and acute renal failure. ) and untreated or inadequately treated extrapyramidal signs and symptoms (EPS). Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, drug fever and primary central nervous system (CNS) pathology.
The management of NMS should include: (1) immediate discontinuation of antipsychotic drugs and other drugs not essential to concurrent therapy, (2) intensive symptomatic treatment and medical monitoring, and (3) treatment of any concomitant serious medical problems for which specific treatment is available.
There is no general agreement about specific pharmacological treatment regimens for uncomplicated NMS. If a patient requires antipsychotic drug treatment after recovery from NMS, the potential reintroduction of drug therapy should be carefully considered.
The patient should be carefully monitored, since recurrences of NMS have been reported.
XYLAC (loxapine) Page 12 of 36 Seizures:
XYLAC should be used with extreme caution in patients with a history of convulsive disorders, since it lowers the convulsive threshold. Seizures have been reported in epileptic patients receiving XYLAC at antipsychotic dose levels, and may occur even with maintenance of routine anticonvulsant drug therapy.
Withdrawal-Emergent Neurological Signs:
Abrupt withdrawal after short-term administration of antipsychotic drugs does not generally pose problems. However, transient dyskinetic signs are experienced by some patients on maintenance therapy after abrupt withdrawal. The signs are very similar to those described under Tardive Dyskinesia, except for duration.
Although it is not known whether gradual withdrawal of antipsychotic drugs will decrease the incidence of withdrawal emergent neurological signs, gradual withdrawal would appear to be advisable.
Parkinson’s Disease and Dementia with Lewy Bodies:
Physicians should weigh the risks versus the benefits when prescribing antipsychotic drugs, including XYLAC, to patients with Parkinson’s disease or dementia with Lewy bodies (DLB) since both groups may be at increased risk of neuroleptic malignant syndrome as well as having an increased sensitivity to antipsychotic medications.
Manifestation of this increased sensitivity can include confusion, obtundation, postural instability with frequent falls, in addition to extrapyramidal symptoms. Ophthalmologic Although clinical experience has not demonstrated ocular toxicity, careful observation should be made for pigmentary retinopathy and lenticular pigmentation, since these have been observed in some patients receiving certain other antipsychotic drugs for prolonged periods.
Because of possible anticholinergic action, the drug should be used with caution in patients with glaucoma particularly with concomitant administration of anticholinergic type of anti- Parkinson medication.
Psychiatric Mental Retardation:
XYLAC has not been evaluated for the management of behavioural complications in patients with mental retardation, and therefore cannot be recommended in these patients.
Suicide:
The possibility of suicide or attempted suicide is inherent in psychosis, and thus, close supervision and appropriate clinical management of high-risk patients should accompany drug therapy. Renal This drug […]