Usage
- Isopropamide is prescribed as adjunctive therapy for peptic ulcers, irritable bowel syndrome (IBS), and other gastrointestinal disorders. It can also help manage conditions causing nausea and vomiting due to its antiemetic properties when used in combination with Trifluoperazine.
- Pharmacological Classification: Anticholinergic, antimuscarinic.
- Mechanism of Action: Isopropamide competitively antagonizes the action of acetylcholine at muscarinic receptors, particularly in the gastrointestinal tract. This leads to decreased gastrointestinal motility and reduced gastric acid secretion.
Alternate Names
- Isopropamide iodide (chemical name)
- Brand Names: Darbid (discontinued), Stelbid (discontinued) and is now commonly combined with Trifluoperazine (Stelazine) and commonly marketed under names such as GASTABID or GASTABID-2 by Torrent LABS (P) LTD.
How It Works
- Pharmacodynamics: Isopropamide decreases the motility of the gastrointestinal tract and diminishes gastric acid secretion. The anticholinergic effects can also lead to dry mouth, blurred vision, urinary retention, and constipation.
- Pharmacokinetics: Isopropamide is administered orally. The onset of action is typically within 1-2 hours, with a duration of action between 6-8 hours.
- Mode of Action: Competitively blocks acetylcholine at muscarinic receptors in the GI tract.
- Receptor Binding: Muscarinic receptor antagonist.
- Elimination Pathways: Primarily renal excretion.
Dosage
Standard Dosage
Adults:
- 5 mg two to three times daily.
- Maximum dose: 40 mg/day.
Children:
- Not recommended for children under 12 years old, unless specifically prescribed.
Special Cases:
- Elderly Patients: Dose reduction may be necessary.
- Patients with Renal Impairment: Dose adjustment based on creatinine clearance may be required.
- Patients with Hepatic Dysfunction: Use with caution.
- Patients with Comorbid Conditions: Careful monitoring in patients with cardiovascular disease, glaucoma, or urinary retention.
Clinical Use Cases
- Data on the use of Isopropamide in intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations is limited. Its use in these settings is not generally recommended.
Dosage Adjustments
Dose adjustments should be made according to individual patient needs and clinical response. Considerations include renal/hepatic impairment, coexisting medical conditions, and potential drug interactions.
Side Effects
Common Side Effects
- Dry mouth
- Blurred vision
- Constipation
- Urinary retention
- Dizziness
- Drowsiness
Rare but Serious Side Effects
- Tachycardia
- Confusion
- Hallucinations
- Allergic reactions
Long-Term Effects
- Chronic complications from prolonged use are not well-documented, but continued monitoring is essential.
Adverse Drug Reactions (ADR)
- Severe anticholinergic effects may require urgent medical attention.
Contraindications
- Hypersensitivity to isopropamide or any component of the formulation.
- Glaucoma
- Urinary retention
- Pyloric stenosis
- Prostatic hypertrophy
- Severe ulcerative colitis
- Bowel obstruction
- Myasthenia gravis
Drug Interactions
- Other anticholinergic drugs: Additive anticholinergic effects.
- Tricyclic antidepressants, MAOIs: Increased risk of anticholinergic side effects.
- CNS depressants (alcohol, opioids, sedatives): Enhanced sedation.
- Antihypertensives: Potential for altered blood pressure control.
- Levodopa, dopamine agonists: Reduced effectiveness of these medications.
- Lithium: Increased risk of constipation and other side effects.
- Antacids: May interfere with absorption of Isopropamide.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: C (potential risks exist; use only if clearly needed)
- Fetal risks are not well-documented.
- Excretion in breast milk: Unknown; breastfeeding not recommended during Isopropamide therapy.
Drug Profile Summary
- Mechanism of Action: Muscarinic receptor antagonist.
- Side Effects: Dry mouth, blurred vision, constipation, urinary retention, dizziness, drowsiness, tachycardia, confusion, hallucinations.
- Contraindications: Glaucoma, urinary retention, pyloric stenosis, prostatic hypertrophy, severe ulcerative colitis, bowel obstruction.
- Drug Interactions: Other anticholinergics, tricyclic antidepressants, MAOIs, CNS depressants, antihypertensives, levodopa, dopamine agonists, lithium, antacids.
- Pregnancy & Breastfeeding: Use with caution in pregnancy (Category C); breastfeeding not recommended.
- Dosage: Adults: 5 mg two to three times daily (max 40 mg/day). Not recommended for children under 12.
- Monitoring Parameters: Heart rate, blood pressure, gastrointestinal function, urinary output.
Popular Combinations
- Trifluoperazine and Isopropamide: This combination is used to treat gastrointestinal disorders associated with mental or emotional factors.
Precautions
- General Precautions: Monitor patients for side effects, adjust dosage in elderly and those with renal or hepatic impairment.
- Specific Populations: Use with caution in pregnant women, avoid during breastfeeding. Not recommended for children under 12.
- Lifestyle Considerations: Alcohol may worsen drowsiness. Avoid driving or operating machinery if experiencing dizziness or blurred vision.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Isopropamide?
A: The standard adult dosage is 5 mg two to three times a day, not exceeding 40mg/day. Dosage adjustments may be needed for the elderly and patients with renal or hepatic impairment. It is not recommended for children under 12.
Q2: What are the common side effects of Isopropamide?
A: Common side effects include dry mouth, blurred vision, constipation, urinary retention, dizziness, and drowsiness.
Q3: What are the contraindications for Isopropamide?
A: Isopropamide is contraindicated in patients with glaucoma, urinary retention, pyloric stenosis, prostatic hypertrophy, severe ulcerative colitis, bowel obstruction, and myasthenia gravis.
Q4: How does Isopropamide work?
A: Isopropamide works by blocking the action of acetylcholine at muscarinic receptors in the GI tract, reducing motility and acid secretion.
Q5: Can Isopropamide be used during pregnancy?
A: Isopropamide is a Pregnancy Category C drug, meaning there are potential risks to the fetus. Use only if clearly needed and under close medical supervision.
Q6: Can Isopropamide be used while breastfeeding?
A: Breastfeeding is not recommended while taking Isopropamide due to unknown risks to the infant.
Q7: What are the serious side effects of Isopropamide?
A: Serious side effects, though rare, can include tachycardia, confusion, hallucinations, and allergic reactions. Seek immediate medical attention if these occur.
Q8: Does Isopropamide interact with other medications?
A: Yes, Isopropamide can interact with other anticholinergics, tricyclic antidepressants, MAOIs, CNS depressants, antihypertensives, levodopa, dopamine agonists, lithium, and antacids.
Q9: What should patients be monitored for while taking Isopropamide?
A: Patients should be monitored for changes in heart rate, blood pressure, gastrointestinal function, and urinary output.
Q10: Is Isopropamide commonly used in combination with other drugs?
A: Yes, Isopropamide is commonly used in combination with Trifluoperazine to treat gastrointestinal disorders associated with mental or emotional factors.
