Chlorpromazine Flashcards
What pharmacologic class of drugs does Chlorpromazine belong to?
Phenothiazine
Broadly speaking what is its mechanism of action?
D2 dopamine receptor antagonist
What is it used to treat?
Positive symptoms of schizophrenia
Controls manic symptoms in schizoaffective disorder
Time of onset?
Oral - 30 to 60 mins
IV/IM - minutes
Peak period?
Oral - 2-4 hours
IV/IM - 15-20 mins
Duration?
30 hours
What cautions should be exercised with sustained release forms of the drug?
Do not crush or open
Is it safe to stop using the drug suddenly?
No, it must be withdrawn over 2 to 3 weeks
What are the withdrawal effects if the drug is stopped suddenly?
Nausea Vomiting Dizziness Tremors Dyskinesia
When is it appropriate to use an IV form of the drug?
Only during surgery or for severe hiccups
What are common adverse effects of Chlorpromazine?
Dizziness Drowsiness Orthostatic hypotension EPS Constipation Photosensitivity Urinary Retention Sedation
In which patient groups do EPS more commonly occur?
Elderly, female and paediatric patients who are dehydrated.
For which symptoms should patients taking the drug who are exposed to higher temperatures be more closely monitored for?
Neuroleptic malignant syndrome
What is the Black Box Warning for this drug?
Elderly patients with dementia related psychosis at increased risk of death
When is Chlorpromazine contra-indicated?
During alcohol withdrawal If patient is in a comatose state CNS Depression Hypothyroidism Phaeochromocytoma
If a patient has what conditions should chlorpromazine be used with caution?
Subcortical brain damage
Bone marrow depression
Reye’s syndrome
Diabetes
What type of drugs is it not safe to use Chlorpromazine with?
Sedative medications such as Phenobarbital
What adverse physiological effect can result from concurrent use of chlorpromazine and tricyclic anti-depressants?
Elevated blood pressure
What can happen with concurrent use of Chlorpromazine and antiseizure meds?
It can lower the seizure threshold
What tests can this drug effect?
Liver function tests
False positive - amylase, 5 hydroxyindole acetic acid, porphobilinogens, urobilinogen and urine bilirubin.
False positive or negative pregnancy tests
What can happen with concurrent use of the drug with either Kava or St John’s Wort?
Increased risk and severity of dystonia
What is dystonia?
Neurological movement disorder syndrome
Sustained or repetitive muscle contractions
Twisting and repetitive movements or abnormal fixed postures.
Resemble a tremor
Is there a treatment for overdose?
No
Patients are treated symptomatically
According to the BNF what group of Phenothiazines does Chlorpromazine Hydrochloride belong to?
Group 1
For schizophrenia/psychoses/anxiety what is the initial dose recommended by the BNF for oral administration?
25mg TID
OR
75mg nochte
What is the max daily dose recommended by BNF for schizophrenia/psychoses/anxiety?
1g daily
What adjustment should be made for elderly/debilitated patients being treated for psychoses/schizophrenia/anxiety?
Use a third to half of adult dose
How is the drug administered in the treatment of acute symptoms of psychoses
Deep IM
When would you use Chlorpromazine to control nausea and vomiting?
In terminal illness where other drugs have failed or are not available
One of the side effects of Chlorpromazine is an Oculogyric crises. What is this?
Dystonic reaction characterized by a prolonged involuntary upward deviation of the eyes.
What precautions must be taken when administering Chlorpromazine intramuscularly?
Patient should remain supine
Monitor Blood Pressure for 30 minutes post treatment
