What is the use of Stemitil (Prochlorperazine) tablets?

Stemitil (Prochlorperazine) Tablets: Primary Uses

Stemitil tablets are primarily used for controlling severe nausea and vomiting, treating schizophrenia, and providing short-term treatment of generalized non-psychotic anxiety (though not as first-line for anxiety). 1

FDA-Approved Indications

The FDA label specifies three main therapeutic uses 1:

• Severe nausea and vomiting control - This is the most common indication in clinical practice 1, 2
• Schizophrenia treatment - As an antipsychotic agent 1
• Short-term non-psychotic anxiety - Limited to maximum 20 mg/day for no longer than 12 weeks due to tardive dyskinesia risk 1

Clinical Applications for Nausea and Vomiting

Recommended Dosing Regimens

Prochlorperazine is used across multiple clinical contexts with established dosing 3:

• Standard antiemetic dosing: 5-10 mg orally four times daily (up to 10 mg every 6 hours as needed) 3
• Chemotherapy-induced nausea: 10 mg orally every 6 hours as needed for grade 1-2 emetogenic potential 3
• Gastroparesis symptoms: 5-10 mg four times daily as part of refractory symptom management 3

Position in Treatment Algorithms

Prochlorperazine functions as a dopamine receptor antagonist, working centrally in the area postrema of the brain to block nausea signals. 3, 2

Current guidelines position prochlorperazine differently depending on clinical context 4, 5:

• First-line for palliative care: Dopamine antagonists including prochlorperazine are recommended as initial therapy, with ondansetron added if symptoms persist 5
• Second-line for general nausea: Modern emergency medicine guidelines favor ondansetron first due to superior safety profile, adding prochlorperazine if ondansetron fails to target different pathways 4
• Combination therapy: When combined with ondansetron, prochlorperazine blocks dopamine pathways while ondansetron blocks serotonin pathways, providing complementary mechanisms 4, 5

Mechanism of Action

Prochlorperazine is a phenothiazine derivative that works as a centrally acting dopamine receptor antagonist 1, 2. The antiemetic action occurs primarily through antidopaminergic mechanisms in the area postrema of the brain 3.

Critical Safety Considerations

Extrapyramidal Symptoms Risk

The most significant concern with prochlorperazine is the risk of extrapyramidal symptoms (EPS), including potentially irreversible tardive dyskinesia with prolonged use. 1, 2

Evidence demonstrates 6, 7:

• Akathisia incidence: 14% of patients developed extrapyramidal symptoms (primarily akathisia) within one week when used for opioid-induced nausea 6
• Tardive dyskinesia: Rare but documented cases occur with long-term use, which is why anxiety treatment is limited to 12 weeks maximum 1, 2
• Real-world safety: In a 500-patient Indian study using recommended doses (mean 14.9 mg/day for 7.2 days), only 0.6% reported adverse effects, all mild 7

Common Pitfalls to Avoid

Always have diphenhydramine available to treat extrapyramidal symptoms if they occur. 4

Additional cautions include 6, 8:

• Monitor for akathisia within the first week of therapy, as this is the most common EPS manifestation 6
• Avoid prolonged use beyond what is necessary for symptom control to minimize tardive dyskinesia risk 1, 2
• Formulation matters: Crushed prochlorperazine maleate tablets are not equivalent to liquid prochlorperazine mesilate; dose adjustments may be needed to account for drug loss during preparation 8

Comparative Effectiveness

Prochlorperazine demonstrates superior efficacy compared to promethazine for uncomplicated nausea and vomiting. 9

A randomized double-blind trial showed 9:

• Significantly better symptom relief at 30 and 60 minutes (P=.004 and P<.001) compared to promethazine
• Shorter time to complete relief (P=.021)
• Fewer treatment failures (9.5% vs 31%, P=.03)
• Less sedation (38% vs 71% complained of sleepiness, P=.002)
• No difference in extrapyramidal effects between the two agents