Usage
Dicyclomine + Mefenamic Acid is prescribed for the relief of abdominal pain and dysmenorrhea (painful menstruation), specifically targeting conditions involving smooth muscle spasms and inflammation within the gastrointestinal tract. It also helps with pain associated with conditions such as irritable bowel syndrome (IBS), intestinal colic, biliary colic, and ureteric colic.
Pharmacological Classification: This combination drug includes two therapeutic agents:
- Dicyclomine: Anticholinergic/Antispasmodic.
- Mefenamic Acid: Non-Steroidal Anti-Inflammatory Drug (NSAID).
Mechanism of Action: Dicyclomine acts as an antispasmodic, reducing muscle contractions in the gastrointestinal tract by blocking the action of acetylcholine at muscarinic receptors. Mefenamic acid inhibits cyclooxygenase (COX) enzymes, thereby reducing prostaglandin production and mitigating pain and inflammation.
Alternate Names
While no specific alternate names exist for this combination, the individual components may be referred to by their respective generic names (dicyclomine hydrochloride and mefenamic acid).
Brand Names: The combination is marketed under various brand names, including:
- Meftal-Spas
- Meftal-Spas DS
- Others (various regional and international brands).
How It Works
Pharmacodynamics: Dicyclomine, by blocking acetylcholine’s effect, reduces smooth muscle spasm and hypermotility in the GI tract. Mefenamic acid’s COX inhibition reduces pain and inflammation by decreasing prostaglandin synthesis.
Pharmacokinetics:
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Dicyclomine: Rapidly absorbed after oral administration, peaking in 60-90 minutes. It’s widely distributed in tissues and primarily excreted in urine (with some fecal excretion). The mean elimination half-life is around 1.8 hours. Metabolism is not well-studied.
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Mefenamic Acid: Absorbed orally, reaching peak levels in 2-4 hours. Metabolized in the liver and primarily excreted in urine and feces. Elimination half-life ranges from 2-4 hours.
Mode of Action: Dicyclomine’s antispasmodic effects arise from competitive antagonism at muscarinic receptors, specifically M1 and M3 subtypes in the GI smooth muscle. Mefenamic acid’s anti-inflammatory and analgesic effects arise from non-selective COX inhibition.
Receptor Binding/Enzyme Inhibition: Dicyclomine is a muscarinic receptor antagonist, while mefenamic acid inhibits cyclooxygenase (COX) enzymes.
Elimination Pathways: Dicyclomine is mainly excreted unchanged in urine, with a smaller portion eliminated in feces. Mefenamic acid is metabolized in the liver and excreted in both urine and feces.
Dosage
Standard Dosage
Adults:
- Meftal-Spas: 1-2 tablets three times daily.
- Meftal-Spas DS: 1 tablet three times daily.
Maximum daily dose of mefenamic acid should not exceed 1500 mg.
Children:
This formulation is NOT intended for use in children due to the lack of dosage adjustment feasibility.
Special Cases:
- Elderly Patients: Increased sensitivity to anticholinergic effects may necessitate a dose reduction. Start with the lowest dose and titrate cautiously as needed.
- Patients with Renal Impairment: Use with caution. Dosage adjustment based on creatinine clearance may be necessary.
- Patients with Hepatic Dysfunction: Use with caution. Dosage adjustment based on liver function may be needed.
- Patients with Comorbid Conditions: Patients with glaucoma, prostatic hypertrophy, hiatus hernia, reflux esophagitis, cardiovascular diseases, or other serious illnesses require careful monitoring.
Clinical Use Cases
This combination is not typically employed in the clinical settings mentioned (Intubation, Surgical Procedures, Mechanical Ventilation, ICU, Emergency Situations). It’s primarily indicated for managing pain and spasm associated with dysmenorrhea and specific GI conditions.
Dosage Adjustments
Dosage modifications based on renal/hepatic impairment, other comorbidities, and individual response are determined on a case-by-case basis.
Side Effects
Common Side Effects:
- Nausea, vomiting, diarrhea
- Dry mouth
- Dizziness, drowsiness, headache
- Blurred vision
- Constipation
Rare but Serious Side Effects:
- Gastrointestinal bleeding or ulceration
- Allergic reactions (rash, urticaria, asthma exacerbation)
- Cardiovascular events (in individuals at risk)
- Renal dysfunction
Long-Term Effects:
Chronic use of NSAIDs like mefenamic acid carries the risk of GI complications, renal issues, and cardiovascular effects. Long-term use of anticholinergics like dicyclomine can lead to dependence.
Adverse Drug Reactions (ADR):
Severe abdominal pain, bloody stools, or vomiting blood necessitate immediate medical attention. Allergic reactions, significant cardiovascular or renal events also require prompt intervention.
Contraindications
- Hypersensitivity to dicyclomine, mefenamic acid, or any NSAIDs.
- Active peptic ulcer or chronic inflammatory bowel disease.
- Significant renal or hepatic impairment.
- Glaucoma, myasthenia gravis, urinary retention.
- Severe heart disease, including coronary artery disease.
- Third trimester of pregnancy, breastfeeding.
Drug Interactions
Dicyclomine can interact with other anticholinergic drugs, potentially enhancing their effects. Mefenamic acid can interact with anticoagulants, antiplatelets, antihypertensives, digoxin, lithium, methotrexate, and other NSAIDs. Concurrent use of alcohol should be avoided. Consult dedicated drug interaction resources for a detailed list.
Pregnancy and Breastfeeding
Contraindicated during pregnancy, especially the third trimester, due to the risk of premature ductus arteriosus closure and other fetal effects. Contraindicated while breastfeeding, as both drugs can be excreted in breast milk and pose risks to the infant.
Drug Profile Summary
- Mechanism of Action: Antispasmodic (dicyclomine) and NSAID (mefenamic acid) targeting smooth muscle spasms and inflammation.
- Side Effects: Nausea, dry mouth, dizziness, blurred vision, GI upset, constipation. Serious side effects: GI bleeding, allergic reactions, cardiovascular events.
- Contraindications: Hypersensitivity, peptic ulcer, severe renal/hepatic impairment, glaucoma, myasthenia gravis, pregnancy, breastfeeding.
- Drug Interactions: Other anticholinergics, anticoagulants, antiplatelets, alcohol, various other medications.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Refer to detailed section above. Varies by brand/formulation.
- Monitoring Parameters: Monitor for GI bleeding, renal function, and cardiovascular effects, especially with long-term use.
Popular Combinations
This combination itself is a common pairing in clinical practice. However, dicyclomine is not commonly prescribed in the United States as it is often ineffective and can cause anticholinergic side effects.
Precautions
- General Precautions: Screen for allergies, assess renal and hepatic function. Monitor for GI and cardiovascular complications.
- Specific Populations: Avoid use in pregnancy, breastfeeding, and children. Exercise caution in the elderly and those with renal or hepatic impairment.
- Lifestyle Considerations: Avoid alcohol to minimize drowsiness and GI risks. Caution with driving or operating machinery due to potential dizziness or drowsiness.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Dicyclomine + Mefenamic Acid?
A: Dosage varies based on product formulation and individual needs. Refer to the detailed dosage section for specific adult dosing. Not for use in children.
Q2: What are the main uses of this medication?
A: Primarily used for relieving abdominal cramps and pain associated with dysmenorrhea and some GI disorders involving smooth muscle spasms.
Q3: Can pregnant or breastfeeding women take this medication?
A: No, it’s contraindicated in both pregnancy and breastfeeding.
Q4: What are the common side effects?
A: Common side effects include nausea, dry mouth, dizziness, blurred vision, GI upset (diarrhea, constipation).
Q5: What are the serious side effects to be aware of?
A: GI bleeding, allergic reactions, cardiovascular effects, and renal dysfunction are potential serious side effects. Seek immediate medical attention if these occur.
Q6: Are there any drug interactions I should be aware of?
A: Yes, consult a drug interaction resource or your pharmacist for a complete list of interactions, including alcohol, anticoagulants, and other medications.
Q7: What precautions should I take while prescribing this drug?
A: Screen for allergies, evaluate renal/hepatic function, consider comorbid conditions, and advise patients about potential side effects, drug interactions, and lifestyle modifications.
Q8: What is the mechanism of action of this combination drug?
A: Dicyclomine is an antispasmodic, blocking acetylcholine’s action on smooth muscle. Mefenamic acid is an NSAID inhibiting COX enzymes and prostaglandin synthesis, reducing pain and inflammation.
Q9: Are there any specific monitoring parameters for patients on long-term therapy?
A: Patients on prolonged therapy should be monitored for GI bleeding, renal function, and cardiovascular effects.
Q10: Can this medicine be used in children?
A: No, this specific formulation is not intended for use in children.
