Loxapine
First-generation antipsychotics
First-generation antipsychotics
A dibenzoxazepine antipsychotic of the first generation for schizophrenia. An inhaled form exists for acute agitation. It lowers the seizure threshold.
Quick facts
- Group
- First-generation antipsychotics
- Target
- Dopamine D2 receptor (antagonist)
- Used for
- Schizophrenia · Acute agitation
- Key effects
- Sedation · Dry mouth · Raised prolactin
- Monitor
- Abnormal movements · Seizures in people with epilepsy
- ATC
- N05AH01
No doses: the clinician sets them by the current guideline.
Mechanism of action
Loxapine is a tricyclic dibenzoxazepine antipsychotic, chemically distinct from phenothiazines and butyrophenones. Like other first-generation agents its antipsychotic effect is linked to dopamine D2 blockade, and it has modest extrapyramidal effects. It calms quickly: sedation starts within half an hour by mouth. It also has anticholinergic actions.
- Loxapine blocks dopamine D2 receptors
- Less mesolimbic dopamine signal: less psychosis
- Sedation within half an hour
- Anticholinergic effects and a lower seizure threshold
Indications
- Schizophrenia Schizophrenia →
- Acute agitation (inhaled form)
Adverse effects
Common
- Sedation, unsteadiness and faintness
- Dry mouth, blurred vision, constipation, difficulty urinating
- Restlessness and abnormal movements
- Raised prolactin: breast milk, breast enlargement, missed periods
Contraindications
- Coma or severe drug-induced CNS depression (alcohol, barbiturates, opioids)
- Hypersensitivity to dibenzoxazepines
Key interactions
- Lorazepam
- Rare reports of significant respiratory depression, stupor or hypotension
- Anticholinergic antiparkinson drugs
- Added anticholinergic effects: caution in glaucoma or urinary retention
- Alcohol and other CNS depressants
- Added sedation
What is monitored
- Abnormal movements
- Seizures in people with epilepsy
- Weight
- Signs of neuroleptic malignant syndrome
Administration and safety
- Oral capsules and the inhaled powder are different products used in different settings
- Caution in glaucoma and urinary retention because of anticholinergic effects
Pregnancy and breastfeeding
Newborns exposed in the third trimester may have extrapyramidal or withdrawal symptoms; use weighs benefit and risk.
Nursing care
- Watches for sedation, dizziness and falls, especially in older patients
- Looks for stiffness, tremor, restlessness and worm-like tongue movements
- Watches breathing and level of consciousness if lorazepam is also given
- Asks about urination and constipation
Pharmacokinetics
- Absorption
- Capsules by mouth; an inhaled powder acts within minutes
- Metabolism
- Extensive liver metabolism; metabolites are excreted mainly in the first 24 hours
- Onset and duration
- Sedation within 20 to 30 minutes by mouth, most marked at 1.5 to 3 hours and lasting about 12 hours
Test yourself
Think of the answer, then tap the question to see it.
To which chemical group does loxapine belong?
Dibenzoxazepines, a tricyclic subclass of first-generation antipsychotics.
Which neurological risk is a specific warning for loxapine?
It lowers the seizure threshold; seizures can occur even in treated epilepsy.
Which combination has caused respiratory depression and stupor?
Loxapine with lorazepam.
Connections
← Back to the class: First-generation antipsychotics
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - LOXAPINE capsule (DailyMed (U.S. National Library of Medicine), 2026); Loxapine: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.