SIDE EFFECTS
CNS Effects: Manifestations of adverse effects on the central nervous
system, other than extrapyramidal effects, have been seen infrequently. Drowsiness,
usually mild, may occur at the beginning of therapy or when dosage is increased.
It usually subsides with continued loxapine (loxapine (loxapine (loxapine succinate) succinate) succinate) therapy. The incidence of sedation
has been less than that of certain aliphatic phenothiazines and slightly more
than the piperazine phenothiazines. Dizziness, faintness, staggering gait, shuffling
gait, muscle twitching, weakness, insomnia, agitation, tension, seizures, akinesia,
slurred speech, numbness, and confusional states have been reported. Neuroleptic malignant syndrome (NMS) has been reported (see WARNINGS).
Extrapyramidal Symptoms - Neuromuscular (extrapyramidal) reactions during
the administration of loxapine (loxapine (loxapine (loxapine succinate) succinate) succinate) have been reported frequently, often during the
first few days of treatment. In most patients, these reactions involved parkinsonian-like
symptoms such as tremor, rigidity, excessive salivation, and masked facies.
Akathisia (motor restlessness) also has been reported relatively frequently.
These symptoms are usually not severe and can be controlled by reduction of
loxapine (loxapine (loxapine (loxapine succinate) succinate) succinate) dosage or by administration of antiparkinson drugs in usual dosage.
DystoniaClass effect: Symptoms of dystonia, prolonged
abnormal contractions of muscle groups, may occur in susceptible individuals
during the first few days of treatment. Dystonic symptoms include: spasm of
the neck muscles, sometimes progressing to tightness of the throat, swallowing
difficulty, difficulty breathing, and/or protrusion of the tongue. While these
symptoms can occur at low doses, they occur more frequently and with greater
severity with high potency and at higher doses of first generation antipsychotic
drugs. An elevated risk of acute dystonia is observed in males and younger age
groups.
Persistent Tardive Dyskinesia- As with all antipsychotic agents, tardive
dyskinesia may appear in some patients on long-term 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 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. It has been suggested 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.
Cardiovascular Effects: Tachycardia, hypotension, hypertension, orthostatic
hypotension, lightheadedness, 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 (loxapine (loxapine (loxapine succinate) succinate) succinate) administration.
Hematologic: Rarely, agranulocytosis, thrombocytopenia, leukopenia.
Skin: Dermatitis, edema (puffiness of face), pruritus, rash, alopecia,
and seborrhea have been reported with loxapine (loxapine (loxapine (loxapine succinate) succinate) succinate) .
Anticholinergic Effects: Dry mouth, nasal congestion, constipation,
blurred vision, urinary retention, and paralytic ileus have occurred.
Gastrointestinal: Nausea and vomiting have been reported in some patients.
Hepatocellular injury (i.e., SGOT/SGPT elevation) has been reported in association
with loxapine (loxapine (loxapine (loxapine succinate) succinate) succinate) administration and rarely, jaundice and/or hepatitis questionably
related to loxapine (loxapine (loxapine (loxapine succinate) succinate) succinate) treatment.
Other Adverse Reactions: Weight gain, weight loss, dyspnea, ptosis,
hyperpyrexia, flushed facies, headache, paresthesia, and polydipsia have been
reported in some patients. Rarely, galactorrhea, amenorrhea, gynecomastia, and
menstrual irregularity of uncertain etiology have been reported.
DRUG INTERACTIONS
There have been rare reports of significant respiratory depression, stupor and/or hypotension with the concomitant use of loxapine (loxapine (loxapine (loxapine succinate) succinate) succinate) and lorazepam.
The risk of using loxapine (loxapine (loxapine (loxapine succinate) succinate) succinate) in combination with CNS-active drugs has not been systematically evaluated. Therefore, caution is advised if the concomitant administration of loxapine (loxapine succinate) and CNS-active drugs is required.