Usage
Dicyclomine + Omeprazole is prescribed for the management of irritable bowel syndrome (IBS) and gastroesophageal reflux disease (GERD). It is also indicated for other gastrointestinal conditions involving spasms and increased acid production.
Pharmacological Classification:
- Dicyclomine: Anticholinergic, Antispasmodic
- Omeprazole: Proton Pump Inhibitor
Mechanism of Action:
Dicyclomine relaxes the smooth muscles of the gastrointestinal tract by blocking acetylcholine at muscarinic receptors. Omeprazole reduces gastric acid secretion by inhibiting the H+/K+ ATPase enzyme system (proton pump) in the parietal cells of the stomach.
Alternate Names
There are no widely recognized alternate names for this specific drug combination itself. However, the individual components have various names:
- Dicyclomine: Dicycloverine Hydrochloride, Dicyclomine HCl. Brand name: Bentyl.
- Omeprazole: Brand names: Prilosec, Losec, Zegerid
How It Works
Pharmacodynamics:
- Dicyclomine: Relaxes smooth muscles, reduces motility of the GI tract
- Omeprazole: Suppresses gastric acid secretion.
Pharmacokinetics:
- Dicyclomine: Well-absorbed orally. Time to peak concentration (Tmax): 1-1.5 hours. Metabolized in the liver, primarily excreted in urine.
- Omeprazole: Rapidly absorbed. Extensively metabolized by the liver (CYP2C19 and CYP3A4). Eliminated primarily in the urine.
Mode of Action:
Dicyclomine acts as an anticholinergic agent, blocking acetylcholine’s effects on muscarinic receptors in the smooth muscle of the GI tract. This leads to decreased muscle tone and reduced spasms.
Omeprazole irreversibly inhibits the H+/K+ ATPase in gastric parietal cells, effectively blocking the final step of acid production.
Receptor binding, enzyme inhibition, or neurotransmitter modulation:
- Dicyclomine: Muscarinic receptor antagonist. Also antagonizes bradykinin and histamine.
- Omeprazole: H+/K+ ATPase inhibitor.
Elimination pathways:
- Dicyclomine: Primarily renal excretion.
- Omeprazole: Hepatic metabolism and renal excretion.
Dosage
Standard Dosage
Adults:
Dicyclomine:
Initial: 20 mg orally four times a day.
Maintenance: Up to 40 mg orally four times a day.
Omeprazole: 20–40 mg once daily. Higher doses may be used in certain conditions such as Zollinger-Ellison syndrome (up to 120mg/day).
Children:
Dicyclomine is generally not recommended for use in children younger than 6 months old, due to increased risk of serious side effects. When prescribed, dosing is based on the child’s weight and age.
Omeprazole dosing in children is weight-based. The usual dose is 0.7–1.4 mg/kg once daily, but this should be determined by a doctor.
Special Cases:
- Elderly Patients: Start with lower doses due to increased sensitivity to anticholinergic effects. Monitor closely.
- Patients with Renal Impairment: Dose adjustment may be needed.
- Patients with Hepatic Dysfunction: Reduce dosage.
- Patients with Comorbid Conditions: Individualized dosing is necessary.
Clinical Use Cases
This drug combination is not typically used in the clinical settings you listed (intubation, surgical procedures, mechanical ventilation, ICU, emergency situations).
Dosage Adjustments
Dose modifications should be based on individual patient characteristics (age, renal/hepatic function, other medical conditions) and response to treatment.
Side Effects
Common Side Effects:
- Dry mouth
- Blurred vision
- Drowsiness
- Dizziness
- Constipation
- Nausea
- Headache
Rare but Serious Side Effects:
- Allergic reactions (angioedema, anaphylaxis)
- Urinary retention
- Worsening of glaucoma
- Cardiac arrhythmias
- Confusion, hallucinations (especially in elderly)
Long-Term Effects:
Long-term use of omeprazole might be associated with an increased risk of certain infections (e.g. Clostridium difficile) and fractures.
Adverse Drug Reactions (ADR):
Any severe allergic reactions, signs of anticholinergic toxicity (confusion, hallucinations, dilated pupils, rapid heart rate, difficulty breathing), or signs of liver problems (jaundice, dark urine) requires immediate intervention.
Contraindications
- Hypersensitivity to dicyclomine or omeprazole
- Obstructive uropathy
- Obstructive gastrointestinal disorders
- Intestinal atony
- Unstable cardiovascular status in acute hemorrhage
- Severe ulcerative colitis
- Toxic megacolon
- Myasthenia gravis
- Glaucoma
- Infants under 6 months of age
Drug Interactions
- Anticholinergics (additive effects)
- Tricyclic antidepressants (additive effects)
- Antihistamines (additive effects)
- Opioids (increased risk of constipation)
- Antacids (may reduce dicyclomine absorption)
- Drugs metabolized by CYP2C19 and CYP3A4 (omeprazole may alter their metabolism)
Pregnancy and Breastfeeding
Dicyclomine: Should be used with caution during pregnancy only if clearly needed. Avoid during breastfeeding.
Omeprazole: Generally considered safe during pregnancy and breastfeeding.
Drug Profile Summary
- Mechanism of Action: Dicyclomine: Anticholinergic, reduces GI motility. Omeprazole: Proton pump inhibitor, reduces gastric acid secretion.
- Side Effects: Dry mouth, blurred vision, drowsiness, constipation, nausea, headache. Serious side effects include allergic reactions, urinary retention, worsening of glaucoma.
- Contraindications: Hypersensitivity, obstructive uropathy/GI disorders, glaucoma, myasthenia gravis, infants under 6 months.
- Drug Interactions: Anticholinergics, tricyclic antidepressants, opioids, antacids.
- Pregnancy & Breastfeeding: Dicyclomine: Use with caution in pregnancy, avoid while breastfeeding. Omeprazole: Generally safe.
- Dosage: Adults: Dicyclomine: 20-40 mg four times daily. Omeprazole: 20-40 mg once daily. Pediatric and special population doses vary.
- Monitoring Parameters: Monitor for adverse effects, especially anticholinergic symptoms and signs of GI bleeding or obstruction.
Popular Combinations
This specific combination is not widely used and is less common than other combinations involving a proton pump inhibitor and drugs addressing other gastrointestinal aspects.
Precautions
- Assess renal and hepatic function before and during treatment.
- Monitor for anticholinergic side effects.
- Caution in elderly patients.
- Avoid in patients with glaucoma, myasthenia gravis, and urinary/GI obstruction.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Dicyclomine + Omeprazole?
A: Dicyclomine: Adults: Initial dose: 20 mg four times daily; may increase to 40 mg four times daily. Omeprazole: Adults: 20–40 mg once daily. Dosages should be adjusted for children, elderly patients, and patients with renal or hepatic impairment.
Q2: What are the common side effects?
A: Common side effects include dry mouth, blurred vision, drowsiness, dizziness, constipation, and nausea.
Q3: Can this combination be used in pregnancy?
A: Dicyclomine should be avoided or used with caution if clearly needed during pregnancy and breastfeeding. Omeprazole is generally considered safe in pregnancy and lactation.
Q4: Are there any contraindications?
A: Contraindications include hypersensitivity to the drugs, glaucoma, myasthenia gravis, urinary or GI obstruction, and infants under 6 months.
Q5: What are the key drug interactions?
A: Dicyclomine interacts with other anticholinergics, enhancing their effects. Omeprazole interacts with drugs metabolized by CYP2C19 and CYP3A4.
Q6: What is the mechanism of action of each component?
A: Dicyclomine is an anticholinergic/antispasmodic, relaxing GI smooth muscle. Omeprazole is a proton pump inhibitor, suppressing gastric acid secretion.
Q7: What precautions should be taken when prescribing this medication?
A: Caution should be exercised in elderly patients due to their susceptibility to anticholinergic side effects. Monitor patients for urinary retention and constipation. Close monitoring of renal and hepatic function is recommended.
Q8: Is this combination commonly used?
A: No, this particular drug combination is not a standard or frequently prescribed treatment regimen compared to other, more conventional treatments for the target conditions.
Q9: What are the signs of an overdose?
A: Overdose symptoms include restlessness, tachycardia, dry mouth, dilated pupils, hallucinations, confusion, and seizures. Supportive care is essential.
Q10: What should be done if a dose is missed?
A: Take the missed dose as soon as remembered, unless it is almost time for the next dose. Do not double the dose.
