Dicyclomine + Famotidine

Usage

This combination is not typically prescribed together as a single formulation. Dicyclomine and Famotidine are often prescribed separately to address different aspects of gastrointestinal disorders.

• Dicyclomine: Prescribed to treat the symptoms of irritable bowel syndrome (IBS). It helps reduce the symptoms of stomach and intestinal cramping.

• Famotidine: Used to treat and prevent ulcers in the stomach and intestines. It can also treat gastroesophageal reflux disease (GERD) and other conditions where the stomach produces too much acid, such as Zollinger-Ellison syndrome.

• Dicyclomine pharmacological classification: Anticholinergic, Antispasmodic

• Famotidine pharmacological classification: H2 receptor antagonist (H2 blocker)

• Dicyclomine mechanism of action: Slows the natural movements of the gut and relaxes the muscles in the stomach and intestines by blocking acetylcholine at muscarinic receptors.

• Famotidine mechanism of action: Decreases stomach acid production by blocking histamine at H2 receptors in the stomach lining.

Alternate Names

Dicyclomine:

• Other Names: Dicycloverine Hydrochloride
• Brand Names: Bentyl, Byclomine, Dibent, Di-Spaz, Dicyclocot

Famotidine:

• Brand names: Pepcid, Pepcid AC, Zantac 360 (Note: Zantac originally referred to Ranitidine, a different H2 blocker, but some formulations now contain Famotidine)

How It Works

Dicyclomine:

• Pharmacodynamics: Relaxes smooth muscle in the gastrointestinal tract, reducing spasms and cramping.

• Pharmacokinetics:

  • Absorption: Well-absorbed orally.
  • Metabolism: Primarily hepatic.
  • Elimination: Renal excretion.

• Mode of Action: Antagonist at muscarinic M1, M2, and M3 receptors. Also exhibits antihistaminic and local anesthetic properties. Reduces gut motility.

• Elimination pathways: Primarily renal excretion

Famotidine:

• Pharmacodynamics: Inhibits gastric acid secretion.
• Pharmacokinetics:
  • Absorption: Incompletely absorbed orally.
  • Metabolism: Limited hepatic metabolism.
  • Elimination: Primarily renal excretion, some in feces.
• Mode of Action: Competitive inhibition of histamine at H2 receptors of gastric parietal cells. Suppresses basal and nocturnal gastric acid secretion stimulated by food, caffeine, insulin, betazole, and pentagastrin.
• Elimination pathways: Primarily renal excretion, small amount in the feces.

Dosage

Since these drugs are not typically combined into a single product, they are dosed separately as indicated below.

Dicyclomine

Standard Dosage

Adults:

Initial dose: 20 mg orally four times a day. Maintenance dose: Up to 40 mg orally four times a day. Administer 30-60 minutes before a meal.

Children:

Infants >6 months (off-label): 5 mg orally every 6-8 hours; maximum 20 mg/day. Children (off-label): 10 mg orally every 6-8 hours; maximum 40 mg/day. Administer 30-60 minutes before meals.

Special Cases:

• Elderly Patients: 10-20 mg orally every 6 hours; may gradually increase as needed, not to exceed 160 mg/day. Use with caution due to higher risk of anticholinergic side effects.
• Patients with Renal Impairment: Use with caution; specific guidelines are not available.
• Patients with Hepatic Dysfunction: Use with caution; specific guidelines are not available.

Famotidine

Standard Dosage

Adults:

• GERD: 20 mg twice daily or 40 mg once daily at bedtime.
• Ulcers: 40 mg once daily at bedtime.
• Heartburn: 10-20 mg every 12 hours as needed.

Children:

Dosing depends on the condition being treated and the child’s weight. The doctor will determine the correct dose for the child.

Special Cases:

• Elderly Patients: Dose adjustments may be needed due to age-related changes in kidney function.
• Patients with Renal Impairment: Dose reduction or longer dosing intervals may be needed.
• Patients with Hepatic Dysfunction: Use with caution; adjustments may be needed.

Clinical Use Cases Dosages for these scenarios should be tailored based on the indication and condition of the patient. Consult specific guidelines. Famotidine can be used in an ICU or surgical procedure setting for stress ulcer prophylaxis.

• Intubation
• Surgical Procedures
• Mechanical Ventilation
• Intensive Care Unit (ICU) Use
• Emergency Situations Dicyclomine is not generally used in emergency situations. Famotidine can be used for upper GI bleeding.

Dosage Adjustments Adjustments are made based on the individual patient’s response to treatment, kidney or liver function, and other medical conditions.

Side Effects

Dicyclomine

Common Side Effects:

Dizziness, drowsiness, blurred vision, dry mouth, dry eyes, nausea, constipation, and abdominal bloating.

Rare but Serious Side Effects:

Decreased sweating, dry/hot/flushed skin, fast/irregular heartbeat, loss of coordination, slurred speech, mental/mood changes (confusion, hallucinations, agitation), eye pain, vision changes, difficulty urinating, decreased sexual ability.

Adverse Drug Reactions (ADR): Anaphylactic shock, apnea

Famotidine

Common Side Effects:

Headache, dizziness, constipation, diarrhea.

Rare but Serious Side Effects:

Confusion, hallucinations, agitation, irregular heartbeat, seizures, difficulty breathing, unusual bleeding or bruising, jaundice (yellowing of skin or eyes).

Contraindications

Dicyclomine: Hypersensitivity to dicyclomine, glaucoma, myasthenia gravis, gastrointestinal obstruction, urinary retention, severe ulcerative colitis, reflux esophagitis, unstable cardiovascular status in acute hemorrhage, infants under 6 months.

Famotidine: Hypersensitivity to famotidine or other H2 blockers.

Drug Interactions

Dicyclomine: Other anticholinergic drugs (antihistamines, tricyclic antidepressants), antacids, digoxin, ketoconazole, metoclopramide.

Famotidine: Antacids, ketoconazole, itraconazole, atazanavir, dasatinib.

Pregnancy and Breastfeeding

Dicyclomine: Dicyclomine should not be used during pregnancy unless clearly needed. Dicyclomine is contraindicated while breastfeeding.

Famotidine: Famotidine is considered generally safe to use during pregnancy and breastfeeding, but it should be used only if clearly needed. Consult a doctor for recommendations.

Drug Profile Summary

Dicyclomine: See above. Famotidine: See above. Monitoring Parameters: Kidney function (especially in elderly or renally impaired patients) should be monitored with both medications. With dicyclomine, monitor for anticholinergic side effects.

Popular Combinations

Dicyclomine is not typically combined with other drugs in a single formulation. Famotidine may be combined with antacids in some over-the-counter products.

Precautions

Dicyclomine: See contraindications and side effects. Use with caution in elderly patients and patients with hepatic or renal impairment. Avoid alcohol.

Famotidine: Use with caution in elderly patients and those with renal impairment.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Dicyclomine?

A: Adults: Initial dose 20 mg four times a day, increasing to 40 mg four times a day as needed. Elderly: 10-20 mg every 6 hours, increasing cautiously. Pediatric use is off-label and dosing should be carefully determined by a physician.

Q2: What is the recommended dosage for Famotidine?

A: Adults: Dosage varies depending on indication. Common dosages are 20 mg twice daily or 40 mg once daily. Pediatric and geriatric dosing should be determined by a physician.

Q3: What are the main side effects of Dicyclomine?

A: Common side effects include dry mouth, blurred vision, dizziness, constipation. Serious side effects can include mental status changes and cardiac arrhythmias.

Q4: What are the main side effects of Famotidine?

A: Common side effects include headache, dizziness, constipation, diarrhea. More serious side effects are rare but can include confusion and cardiac arrhythmias.

Q5: Can Dicyclomine be used during pregnancy or breastfeeding?

A: Dicyclomine is generally contraindicated during pregnancy and breastfeeding.

Q6: Can Famotidine be used during pregnancy or breastfeeding?

A: Famotidine can be used during pregnancy and breastfeeding if clearly needed, but it is important to discuss the risks and benefits with a doctor.

Q7: What conditions is Dicyclomine commonly used to treat?

A: Dicyclomine is most often used to treat symptoms of irritable bowel syndrome (IBS).

Q8: What conditions is Famotidine commonly used to treat?

A: Famotidine is used to treat ulcers, GERD, and other conditions causing excess stomach acid.

Q9: What are the key drug interactions to be aware of with Dicyclomine?

A: Dicyclomine interacts with other anticholinergic drugs, antacids, and certain antifungals.

Q10: What are the key drug interactions to be aware of with Famotidine?

A: Famotidine can interact with antacids and some antifungal medications. It can also affect the absorption of certain other drugs.