Antipsychotic Medications Anti-psychotic Drugs loxapine, Loxitane

Antipsychotic: loxapine, Loxitane

Generic Name: loxapine
Brand Name(s): Loxitane
Common Use: Antipsychotic

Contraindications
Comatose or severe drug induced depressed states (alcohol, barbiturates, narcotics, etc.), known hypersensitivity to loxapine, patients with circulatory collapse.

Adverse Side Effects

CNS:
The incidence of sedation following loxapine administration has been less than that of certain aliphatic phenothiazines and slightly more than the piperazine phenothiazines. Drowsiness, usually mild, may occur at the beginning of therapy or when dosage is increased. It usually subsides with continued loxapine therapy. Dizziness, faintness, headache, staggering gait, shuffling gait, muscle twitching, weakness, insomnia, agitation, tension, seizures, akinesia, slurred speech, numbness, paresthesia and confusional states have been reported. Neuroleptic malignant syndrome has been reported (see Warnings).

Extrapyramidal Reactions:
Neuromuscular (extrapyramidal) reactions during loxapine administration have been reported frequently, often during the first few days of treatment. In most patients, these reactions involved Parkinson-like symptoms such as tremor, rigidity, excessive salivation and masked facies. These symptoms are not usually severe and can be controlled by reduction of loxapine dosage or by administration of antiparkinson drugs in usual dosage. Akathisia (motor restlessness) also has been reported relatively frequently. These symptoms are usually not severe and can be controlled by reduction of loxapine dosage. Dystonic and dyskinetic reactions have occurred less frequently, but may be more severe and may occur during the first few days of treatment. Dystonias include spasms of muscles of the neck and face, tongue protrusion and oculogyric movement. Dyskinetic reaction has been described in the form of choreoathetoid movements. These reactions sometimes require reduction or temporary withdrawal of loxapine dosage in addition to appropriate counteractive drugs.

Tardive Dyskinesia:
As with all antipsychotic agents, tardive dyskinesia may appear in some patients on longterm therapy or may appear after drug therapy has been discontinued. The risk appears to be greater in elderly patients on high dose therapy, especially females. The symptoms are persistent and in some patients appear to be irreversible. The syndrome is characterized by rhythmical involuntary movement of the tongue, face, mouth or jaw (e.g. protrusion of tongue, puffing of cheeks, puckering of mouth, chewing movements). Sometimes these may be accompanied by involuntary movements of the extremities.
There is no known effective treatment for tardive dyskinesia; antiparkinson agents usually do not alleviate the symptoms of this syndrome. It is suggested that all antipsychotic agents be discontinued if these symptoms appear. Should it be necessary to reinstitute treatment, or increase the dosage of the agent, or switch to a different antipsychotic agent, the syndrome may be masked. The physician may be able to reduce the risk of this syndrome by minimizing the unnecessary use of neuroleptic drugs and reducing the dose or discontinuing the drug, if possible, when manifestations of this syndrome are recognized, particularly in patients over the age of 50. It has been reported that fine vermicular movements of the tongue may be an early sign of the syndrome and if the medication is stopped at that time the syndrome may not develop.

Autonomic:
Dry mouth, nasal congestion, constipation, blurred vision, urinary retention and paralytic ileus have occurred.

Cardiovascular:
Tachycardia, hypotension, hypertension, light-headedness and syncope have been reported. A few cases of ECG changes similar to those seen with phenothiazines have been reported. It is not known whether these were related to loxapine administration.

Hematologic:
Rarely, agranulocytosis, thrombocytopenia and leukopenia.

Gastrointestinal:
Nausea and vomiting have been reported in some patients.
Hepatocellular injury (i.e. AST(SGOT), ALT(SGPT), elevation) has been reported in association with loxapine administration and rarely, jaundice and/or hepatitis questionably related to loxapine treatment.

Dermatological:
Dermatitis, edema (puffiness of face), pruritus and seborrhea have been reported with loxapine. The possibility of photosensitivity and/or phototoxicity occurring has not been excluded; skin rashes of uncertain etiology have been observed in a few patients during hot summer months.

Endocrine:
Rarely, galactorrhea, amenorrhea, gynecomastia and menstrual irregularity of uncertain etiology have been reported.

Other Adverse Reactions:
Weight gain, weight loss, dyspnea, ptosis, hyperpyrexia, flushed facies, and polydipsia have been reported in some patients.

Overdose

May range from mild depression of the CNS and cardiovascular systems to profound hypotension, respiratory depression and unconsciousness. Overdosage may lead to convulsive seizures. Renal failure following loxapine overdosage has also been reported. No specific antidote is known. The treatment of overdosage would be essentially symptomatic and supportive.

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