Clozapinum
Description
An atypical antipsychotic drug that rarely causes extrapyramidal
symptoms. It has sedative and antimuscarinic effects. Can cause
agranulocytosis.
Indications
Resistant schizophrenia to treatment (with typical antipsychotic
drugs).
Contraindications
Hypersensitivity to the drug; previous drug-induced
granulocytopenia or agranulocytosis, impaired
bone marrow function; coma; uncontrolled
epilepsy; alcoholic or other toxic psychoses;
severe liver, kidney, and heart failure;
history of paralytic ileus.
Dosage
For adults. Oral administration. Initial dose – 12.5
mg 1-2 times a day, increase by 25-50 mg per
day up to 300-450 mg, further increase by 50-
100 mg per week if needed, maximum daily dose – 900
mg, maintenance dose – 150-300 mg per day.
For children. Not recommended under 16 years.
For elderly. Initial dose – 12.5 mg once a day,
increase by 25 mg per day.
Renal impairment. Initial dose – 12.5 mg once a day,
increase slowly.
Hepatic impairment. Initial dose – 12.5 mg once a day,
increase slowly.
Adverse reactions
Most common: orthostatic hypotension, tachycardia;
sedation, drowsiness; dizziness; sialorrhea,
increased appetite.
Others: agranulocytosis (usually within the first 18
weeks); seizures; ECG changes, hypertension; pericarditis,
myocarditis; transient hyperthermia (first
3 weeks); insomnia, nightmares, delirium;
malignant neuroleptic syndrome; tremors,
akathisia; sweating; dry mouth, constipation, paralytic ileus,
nausea, vomiting, diarrhea; weight gain;
urinary incontinence or retention; priapism,
impotence; increased liver enzyme
concentration, asymptomatic (at the beginning of treatment), hyperglycemia; temporary increase in prolactin
concentration; periorbital edema.
Pregnancy
Risk category – BM. Breastfeeding
Clozapine concentrates in breast milk. The concentration
ratio of clozapine in breast milk to plasma is
4.3. Breastfeeding is not recommended while taking the drug.
Warnings
Before prescribing the drug, determine the leukocyte count and
repeat the test within the first 18 weeks weekly, later
monthly. Discontinue the drug when leukocytes <3000
mm3 and (or) neutrophils <1500 mm3. Administer with caution
in case of heart, liver, and kidney diseases, prostate
hyperplasia, closed-angle glaucoma, history or
current seizures. Avoid alcohol consumption. Do not
drive or operate dangerous machinery.
Do not abruptly discontinue drug use.
Do not administer with other blood-thinning
medications.
Source | Drug Guide | Lithuanian University of Health Sciences | Institute of Physiology and Pharmacology | Doctor of Medical Sciences Rimas Jankūnas, Doctor of Medical Sciences Arvydas Milašius | Clinic of Internal Diseases | Doctor of Medical Sciences Palmira Leišytė