Usage
Isopropamide + Trifluoperazine is indicated for the management of gastrointestinal disorders, primarily:
- Irritable Bowel Syndrome (IBS)
- Peptic Ulcers
- Indigestion/Dyspepsia
- Gastroesophageal Reflux Disease (GERD) (off-label)
- Medicine-induced diarrhea
- Genitourinary spasms
Pharmacological Classification:
- Isopropamide: Anticholinergic/antispasmodic
- Trifluoperazine: Antipsychotic/antiemetic
Mechanism of Action:
Isopropamide, an anticholinergic agent, blocks acetylcholine’s action, relaxing gastrointestinal smooth muscle, reducing spasms and pain. Trifluoperazine, a phenothiazine antipsychotic, acts as a dopamine antagonist, reducing anxiety and nausea by acting on the chemoreceptor trigger zone (CTZ). At the doses used in this combination, it primarily exerts an antiemetic effect rather than a significant antipsychotic action.
Alternate Names
- Stelbid
- Gastabid
- Spascol
- Telabid
How It Works
Pharmacodynamics:
Isopropamide reduces gastrointestinal motility and secretions. Trifluoperazine exerts antiemetic effects by blocking dopamine receptors in the CTZ.
Pharmacokinetics:
The pharmacokinetics of the combination product have not been specifically studied. However, both drugs are absorbed orally. Isopropamide is primarily metabolized in the liver, while trifluoperazine undergoes extensive hepatic metabolism via CYP enzymes. Both drugs are eliminated through renal and hepatic routes.
Mode of Action:
Isopropamide competitively inhibits the action of acetylcholine at muscarinic receptors, leading to smooth muscle relaxation in the GI tract. Trifluoperazine blocks dopamine D2 receptors in the CTZ, inhibiting nausea and vomiting.
Receptor Binding, Enzyme Inhibition, or Neurotransmitter Modulation:
Isopropamide binds to muscarinic receptors. Trifluoperazine blocks dopamine D2 receptors. Specific CYP enzyme interactions for trifluoperazine metabolism have not been comprehensively characterized in this combination product.
Dosage
Standard Dosage
Adults:
One tablet (containing 1mg Trifluoperazine and 5mg Isopropamide) twice daily, every 12 hours.
Children:
Not recommended for children under 6 years of age.
- 6-12 years: 1mg Trifluoperazine once or twice daily (max 15mg/day). Isopropamide dosing in this age range is not well-established and should be determined by a physician based on individual patient factors.
- Over 12 years: Adult dose may be used.
Special Cases:
- Elderly Patients: Initiate at the lower end of the dose range and titrate cautiously due to increased sensitivity to anticholinergic effects.
- Patients with Renal Impairment: Caution is advised; dose adjustments may be necessary based on clinical response.
- Patients with Hepatic Dysfunction: Use with caution; dose adjustments may be necessary based on the degree of impairment.
- Patients with Comorbid Conditions: Caution in patients with cardiovascular disease, glaucoma, prostatic hypertrophy, and urinary retention.
Clinical Use Cases
The combination is not typically used in the clinical settings described (Intubation, Surgical Procedures, Mechanical Ventilation, ICU Use, Emergency Situations).
Dosage Adjustments
Dose modifications may be required for renal/hepatic dysfunction, or in elderly patients. Dosage adjustments based on metabolic disorders or genetic polymorphisms affecting drug metabolism are not specifically defined for this combination product.
Side Effects
Common Side Effects
- Nausea
- Dry mouth
- Constipation
- Drowsiness
- Dizziness
- Blurred vision
- Urinary retention
Rare but Serious Side Effects
- Hypotension
- Extrapyramidal symptoms (e.g., dystonia, tardive dyskinesia)
- Neuroleptic malignant syndrome (NMS)
Long-Term Effects
Tardive dyskinesia can be a long-term side effect of trifluoperazine.
Adverse Drug Reactions (ADR)
NMS is a rare but serious ADR requiring immediate intervention.
Contraindications
- Hypersensitivity to Isopropamide, Trifluoperazine, or phenothiazines
- Angle-closure glaucoma
- Pyloric stenosis
- Prostatic hypertrophy
- Severe respiratory depression
- Blood dyscrasias or bone marrow depression
- Parkinson’s disease
- Coma or CNS depression
- Intestinal obstruction
Drug Interactions
- Anticholinergic drugs (additive effects)
- CNS depressants (e.g., alcohol, opioids, sedatives) - increased CNS depression
- Antihypertensives – enhanced hypotensive effect
- Levodopa and dopamine agonists - reduced efficacy
- Lithium - increased risk of constipation and other anticholinergic side effects
- Antacids – possible reduced absorption of Isopropamide + Trifluoperazine
- Quinidine, Codeine, Cetirizine, Insulin Aspart – potential for interactions, though clinical significance needs individual assessment
Pregnancy and Breastfeeding
- Pregnancy: Not recommended due to potential fetal risks (Pregnancy Category C).
- Breastfeeding: Not recommended as it can pass into breast milk and potentially harm the infant.
Drug Profile Summary
- Mechanism of Action: Isopropamide: Anticholinergic; Trifluoperazine: Dopamine antagonist
- Side Effects: Nausea, dry mouth, constipation, drowsiness, dizziness, blurred vision, urinary retention. Serious: hypotension, extrapyramidal symptoms, NMS.
- Contraindications: Hypersensitivity, glaucoma, pyloric stenosis, prostatic hypertrophy, bowel obstruction
- Drug Interactions: Anticholinergics, CNS depressants, antihypertensives, levodopa, lithium
- Pregnancy & Breastfeeding: Not recommended
- Dosage: Adults: 1 tablet (5mg/1mg) twice daily
- Monitoring Parameters: Blood pressure, heart rate, mental status, bowel function, urinary function
Popular Combinations
No established “popular combinations” exist for fixed-dose Isopropamide + Trifluoperazine. Other medications may be prescribed concurrently to address specific symptoms or comorbid conditions.
Precautions
- General Precautions: Pre-existing medical conditions (especially cardiovascular, hepatic, renal, and glaucoma) should be assessed before prescribing.
- Specific Populations: Pregnant women, breastfeeding mothers and children require specific precautions as above.
- Lifestyle Considerations: Alcohol should be avoided. Caution advised while driving or operating machinery due to potential drowsiness and dizziness.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Isopropamide + Trifluoperazine?
A: Adults: One tablet (1mg Trifluoperazine/5mg Isopropamide) twice daily. Not recommended for children under 6. Dosage adjustments may be needed for elderly patients or those with hepatic/renal impairment.
Q2: What are the primary uses of this medication?
A: Primarily IBS, peptic ulcers, and indigestion. Off-label uses include GERD, medicine-induced diarrhea, and genitourinary spasms.
Q3: What are the common side effects?
A: Dry mouth, blurred vision, constipation, urinary retention, drowsiness, dizziness.
Q4: Are there any serious side effects I should be aware of?
A: Yes, though rare, neuroleptic malignant syndrome (NMS) and extrapyramidal symptoms can occur. Seek immediate medical attention if these occur.
Q5: Can this medication be used during pregnancy or breastfeeding?
A: No, it’s generally not recommended due to potential risks to the fetus or infant.
Q6: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember unless it’s almost time for the next dose. Do not double the dose.
Q7: Does this medication interact with other drugs?
A: Yes, it can interact with several medications, including anticholinergics, CNS depressants, antihypertensives, levodopa, and lithium. Inform your physician about all other medications you are taking.
Q8: What are the contraindications for Isopropamide + Trifluoperazine?
A: Contraindications include hypersensitivity to the components, glaucoma, pyloric stenosis, prostatic hypertrophy, bowel obstruction, and certain other medical conditions.
Q9: How should this medication be stored?
A: Store at room temperature away from light and moisture. Keep out of reach of children.
