Pericyazine

Pericyazine(中文:[[ ]]) is a typical antipsychotic medication. Periciazine is indicated:

1. In adults with schizophrenia or other psychoses, for the treatment of symptoms or prevention of relapse.
2. As a short-term adjuntive management of severe anxiety, and violent or dangerously impulseive behavior.

Periciazine is not recommended for children.

Pronunciation

Pericyazine 10mg

Pericyazine 2.5mg

Drug Names

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Pericyazine Tab 2.5 mg	PERI01	P1S1S3
Pericyazine Tab 10 mg	PERI02	P1S1S3

Mechanism of Action

Pericyazine is presumed to act primarily in the subcortical areas, by blocking central alpha-adrenergic receptors and the D1 dopamine receptor. The presumed effectiveness of antipsychotic drugs relied on their ability to block dopamine receptors. This assumption arose from the dopamine hypothesis that maintains that both schizophrenia and bipolar disorder are a result of excessive dopamine activity.

Dosage

Indication	Dose
Schizophrenia and other psychoses	By mouth ADULT: Initially 75 mg daily in divided doses, Increased at weekly intervals by 25 mg, according to response. Maximum 300 mg per day. ELDERLY or debilitated patients: Initially 15-30 mg daily in divided doses, then Increased at weekly intervals by 25 mg, according to response. Maximum 300 mg per day
Short-term adjunctive management of severe anxiety, and violent or dangerously impulse behaviour	By mouth ADULT: 15-30 mg daily in 2 divided doses ELDERLY or debilitated patients: 5-10 mg 2-3 daily in 2 divided doses

Side Effects

Most serious and/or frequently occurring adverse effects of periciazine include the following: Possible side effects include:

Behavioral:	Drowsiness is common at the start of treatment, but this effect usually eases off within a few days. Impaired psychomotor activity is a frequent side-effect.
Hepatic:	Jaundice occurs in a very small percentage of patients. Treatment should be withheld on the development of jaundice
Cardiovascular:	Postural hypotension commonly occurs, especially in the elderly.
Haematological:	Agranulocytosis may occur rarely. The occurrence of unexplained infections or fever requires immediate haematological investigation.
Nervous system:	Extrapyramidal effects include: Acute dystonia, akathisia Parkinsonism shown as tremor, rigidity, akinesia, is more common in the elderly
Tardive Dyskinesia	It may appear in patients on long term therapy. The risk appears to be greater in elderly patients on high dose therapy, especially females. It is characterized by rhythmical involuntary movement of tongue, face, mouth, or jaw (e.g. protrusion of tongue, puffing of cheeks, puckering of mouth, chewing movements).
Neuroleptic Malignant Syndrome:	A potentially fatal syndrome. It is characterized by muscular rigidity, fever, hyperthermia, and autonomic instability (e.g. tachycardia, labile blood pressure, profuse sweating, dyspnoea)
Skin:	Owing to contact skin hypersensitivity should avoid direct contact with the drug, Because of the risk of photosensitization, patients should be advised to avoid exposure to direct sunlight and that retinal changes may occur.

Pharmacokinetics

Oral bioavailability	Haloperidol is readily absorbed after oral doses.
Onset of action	Peak plasma concentrations achieve about 2 hours after ingestion.
Metabolism	It is extensively metabolized in the liver
Elimination half-life	It is excreted in the urine and faeces. The elimination half-life is approximately 12 hours. There is high inter-patient variability

Drug Management

Monitoring

• Full blood count, serum potassium, and liver function test is required at the start of therapy, and then annually thereafter.
• Fasting blood glucose should be monitored at start of therapy, at 4-6 months, and then yearly
• Blood pressure and BMI
• Patients on long-term treatment should receive regular eye examinations.
• Careful monitoring is required in the elderly who are particularly susceptible to postural hypotension, sedation, and extrapyramidal effects, chronic constipation, and possible prostatic hypertrophy.

Drug interaction

The metabolism of pericyazine is mediated by the cytochrome P450 system, particularly the isoenzymes CYP3A4 and CYP2D6. Therefore, there is the potential for interactions between pericyazine and other drugs that induce, inhibit, or act as a substrate for these isoenzymes, resulting in altered plasma pericyazine concentrations.

Drugs given with pericyazine	Potential Effect
CNS-depressant drugs including alcohol, hypnotics, anxiolytics, sedative H1 antihistamines, central antihypertensives, baclofen, thalidomide and opioids.	Potentiates the sedative effect. Impaired vigilance may make it dangerous to drive or use machines.
Lithium	Might increase the risk of lithium poisoning or neuroleptic malignant syndrome. Regular monitoring of serum lithium should be performed.
Tricyclic antidepressants such as amitriptyline, a CYP2D6 substrate, and pericyazine is potent inhibitor of CYP2D6.	Metabolism and elimination of tricyclics significantly decreased, increased toxicity such as anticholinergic and cardiovascular side effects.
Levodopa	In theory, antipsychotics with dopamine-blocking activity and dopaminergic drugs such as those used to treat parkinsonism may be mutually antagonistic.
Drugs that prolong the QT interval e.g. amiodarone, sotalol, quinidine Drugs which induce bradycardia e.g. diltiazem, verapamil Drugs which can cause hypokalaemia such as diuretics e.g. frusemide	An increased risk of ventricular arrhythmias – avoid concomitant use.