Study Guide for Chlorpromazine

·         Generic Name: Chlorpromazine

·         Brand Names: Ormazine, Thorazine spansule and Thorazine.

·         Approved FDA Indications: Schizophrenia, the acute manic phase of bipolar I disorder, persistent hiccups, acute agitation, relief of anxiety preoperatively, acute intermittent porphyria, and as an adjunctive treatment for tetanus (Mann & Marwaha, 2020).

·         Off-label Uses: Treatment for migraine-associated nausea and vomiting and treatment for serotonin syndrome.

·         Half-life: 23 to 37 hours.

·         About 90-99% is protein bound.

·         It undergoes hepatic metabolism via the CYPA12 and the CYP2D6 enzymes (Mann & Marwaha, 2020).

·         Excretion is via urine and feces.

·         Initially, the patients may experience increased dopaminergic neural activity due to rebound production of dopamine. With the continued blockade, reduced neural activity ensues.

o   Oral intake: Tablets of various dosages between 10–200mg.

o   Parenteral use: Can be administered intramuscularly and intravenously.

·         Dosing varies and is dependent on the indication for use.

·         For schizophrenia, the initial dose is 25-75mg orally twice a day and maintenance of 200 mg once daily. If it is to be administered as an intravenous or intramuscular injection, the initial dose is 25 mg, followed by 25-50 mg every 1-4 hours (Keepers et al., 2020).

·         Caution should be taken for patients with hepatic failure or liver disease.

·         No need for dose adjustment for patients with renal disease.

·         Pregnancy: Chlorpromazine can be used but in low doses and when the clinician is certain that the benefits outweigh the risks.

·         It also helps in determining the frequency of administration of the drug.

· D2 receptor blockade causes hyperprolactinemia, hence reducing libido in both males and females (Zhu et al., 2021).

In males, there may be associated erectile dysfunction, galactorrhea, and gynecomastia.

In females, there may be amenorrhea, oligomenorrhea, galactorrhea, and irregular menses.

·         Extrapyramidal effects include akathisia, tardive dyskinesia, parkinsonism, neuroleptic malignant syndrome, and dystonia(Geddes & Andreasen, 2020).

·         Others: headache and hypotension when given parenterally, prolonged QT interval, cholestatic jaundice, and hepatotoxicity.

·         Caution should be taken when administered to patients who are on anti-hypertensives due to the risk of developing hypotension.

·         The drugs should be avoided in patients with uncontrolled seizures and should not be used in combination with drugs suppressing the central nervous system.

·         Chlorpromazine may affect the therapeutic effects of drugs, causing dopamine agonists such as cabergoline and levodopa.

·         Concomitant use of chlorpromazine with escitalopram and citalopram is contraindicated.

·         Caution should be taken when administered to pregnant and breastfeeding mothers.

(Geddes & Andreasen, 2020).

·         Following ingestion of large doses, gastric lavage should only be attempted within the first four to six hours following ingestions. Another alternative is activated charcoal.

·         An electrocardiogram is essential to check for prolongation of QT interval and arrhythmias.

·         In case a patient develops neuroleptic malignant syndrome, offer supportive care, which includes giving dantrolene sodium and cooling the patient. However, when a patient develops tardive dyskinesia, discontinue chlorpromazine and consider switching to second-generation antipsychotics.

(Keepers et al., 2020)

·         Elecertocardiogram for each visit to check for QT prolongation.

·         Regular monitoring of the liver enzymes and the bilirubins as chlorpromazine is metabolized in the liver. Caution should be taken in case of liver disease.

(Keepers et al., 2020)

·         Administer with caution for patients with cardiovascular and cerebrovascular disorders.

·         Avoid concomitant use of chlorpromazine with anti-hypertensive drugs due to the risk of hypotension.

·         The drug is contraindicated in patients with liver failure.

(Mann & Marwaha, 2020)

·         It is important to abide by the patient’s decision while on treatment.

(Gandhi, 2022)

·         Educate the patients on the potential side effects and advise them to seek medical attention once they notice life-threatening adverse reactions or hypersensitivity.

·         Patients should be advised to quit or reduce alcohol consumption while on medications.

·         Give nutritional counseling and advice on a healthy diet when taking chlorpromazine.

(Gandhi, 2022)