Loxapine


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Psychoses Initial: 20-50 mg/day in 2 divided doses, increased to 60-100 mg/day in 2-4 divided doses according to response. Max: 250 mg/day. Maintenance: 20-60 mg/day in divided doses. IM Acute psychosis 12.5-50 mg 4-6 hrly. Dosage and dosing interval may be adjusted based on patient response. Inhalation Acute agitation associated w/ schizophrenia or bipolar disorder 10 mg/24 hr via inhaler device.
Dosage Details
Inhalation/Respiratory
Acute agitation
Adult: In patients w/ schizophrenia or bipolar disorder: 10 mg/24 hr via inhaler device.

Intramuscular
Acute psychosis
Adult: 12.5-50 mg at intervals of 4-6 hr. Dosage and dosing interval may be adjusted based on patient response.

Oral
Psychoses
Adult: Initially, 20-50 mg daily in 2 divided doses, increased over the next 7-10 days to 60-100 mg daily in 2-4 divided doses, according to response. Max: 250 mg daily. Maintenance: Use the lowest effective dose between 20-60 mg daily in divided doses.
Administration
Should be taken with food.
Contraindications
Severe drug-induced CNS depression, coma (oral); current diagnosis or history of asthma, COPD, bronchospasm, or acute resp symptoms (inhalation).
Special Precautions
Patient w/ decreased GI motility, paralytic ileus, urinary retention, BPH, xerostomia, glaucoma, or visual problems, low WBC count, risk of pneumonia, CV diseases, dehydration, cerebrovascular disease, hypovolaemia, Parkinson's disease; history of extrapyramidal symptoms, drug-induced leucopenia/neutropenia, risk factors for seizures (including those w/ history of seizures, head trauma, brain damage, alcoholism). Not indicated for dementia-related psychosis. Avoid abrupt withdrawal or dose reduction. Pregnancy and lactation.
Adverse Reactions
Significant: Anticholinergic effects (e.g. constipation, xerostomia, blurred vision, urinary retention), CNS depression, oesophageal dysmotility/aspiration, extrapyramidal symptoms (e.g. pseudoparkinsonism, acute dystonic reactions, akathisia, tardive dyskinesia), risk of fall due to somnolence and motor or sensory instability, hyperprolactinaemia, neuroleptic malignant syndrome, pigmentary retinopathy, lenticular and corneal deposits, orthostatic hypotension, hypotension, syncope, impaired core body temp regulation.
Nervous: Sedation, agitation, confusion, dizziness, drowsiness, headache, insomnia, numbness, paraesthesia, seizure, slurred speech, tension, unsteady gait.
CV: ECG changes, oedema, HTN, tachycardia.
GI: Polydipsia, constipation, nausea, paralytic ileus, vomiting, xerostomia and dysgeusia (inhalation).
Resp: Dyspnoea, nasal congestion.
Hepatic: Hepatitis, increased serum ALT/AST, jaundice.
Genitourinary: Impotence, urinary retention, priapism.
Endocrine: Amenorrhoea, galactorrhoea, gynaecomastia, menstrual disease, wt gain, wt loss.
Musculoskeletal: Muscle twitching, muscle weakness.
Dermatologic: Flushing, alopecia, dermatitis, pruritus, seborrhoea, skin photosensitivity, rash.
Immunologic: Hypersensitivity (inhalation).
Others: Hyperpyrexia.
Potentially Fatal: Bronchospasm leading to resp distress and resp arrest. Blood dyscrasias (e.g. leucopenia, neutropenia, agranulocytosis).
IM/Inhalation/Respiratory/Parenteral/PO: C
Patient Counseling Information
This drug may cause somnolence, motor and sensory instability, if affected, do not drive or operate machinery.
MonitoringParameters
Monitor hyperpyrexia, mental status changes, fever, muscle rigidity and autonomic instability, LFT, serum electrolyte level, menstrual changes, libido, abnormal involuntary movements or parkinsonian sign, tardive dyskinesia, visual changes. Monitor signs and symptoms of bronchospasm after oral inhalation admin.
Overdosage
Symptoms: Mild CNS depression, hypotension, resp depression, unconsciousness, severe extrapyramidal reactions, renal failure. Management: Symptomatic and supportive treatment. Empty stomach immediately by gastric lavage. Avoid emesis due to the possible aspiration of vomitus. Avoid analeptics (e.g. pentylenetetrazol), which may cause convulsions. Avoid epinephrine admin in patient w/ partial adrenergic blockade due to further lowering of BP. May give anticholinergic antiparkinsonian agent, diphenhydramine or anticonvulsant drugs to treat severe extrapyramidal symptoms. Extended haemodialysis may be useful in enhancing elimination.
Drug Interactions
Additive effect w/ other CNS or resp depressants (e.g. benzodiazepines, barbiturates, opioids) leading to excessive sedation and resp depression or resp failure. Loxapine may enhance the effect of anticholinergic drugs (e.g. aclidinium, cimetropium, ipratropium).
Food Interaction
Additive CNS depressant effect w/ alcohol.
Lab Interference
May give false positive result for phenylketonuria, amylase, uroporphyrins, urobilinogen.
Action
Description: Loxapine is a tricyclic dibenzoxazepine-derivative antipsychotic agent. It blocks postsynaptic mesolimbic dopamine D1 and D2 receptors in the brain. It also inhibits serotonin 5-HT2 receptors.
Onset: W/in 20-30 min (oral); 2 min (inhalation).
Duration: Approx 12 hr (oral).
Pharmacokinetics:
Absorption: Rapidly and completely absorbed. Time to peak plasma concentration: W/in 1-2 hr (oral); w/in 2 min (inhalation).
Distribution: Widely distributed in body tissues. Plasma protein binding: Approx 97% (inhalation).
Metabolism: Metabolised rapidly and extensively in the liver via hydroxylation into 8-OH-loxapine and 7-OH-loxapine metabolites, further metabolised via N-oxidation to form loxapine N-oxide metabolites, and via N-demethylation into amoxapine metabolite. Undergoes first-pass metabolism.
Excretion: Mainly via urine (40%, as conjugated metabolites); via faeces (10%, as unconjugated metabolites). Elimination half-life: 6-8 hr (inhalation). Oral: Biphasic: Initial: 5 hr; terminal: 19 hr.
Chemical Structure

Click on icon to see table/diagram/image
Storage
Store between 15-30°C.
MIMS Class
ATC Classification
N05AH01 - loxapine ; Belongs to the class of diazepines, oxazepines and thiazepines antipsychotics.
Disclaimer: This information is independently developed by MIMS based on Loxapine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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