Usage
Drotaverine + Mefenamic Acid is prescribed for the relief of pain and muscle spasms, particularly in conditions involving smooth muscles. It is commonly used to treat:
- Abdominal pain and cramps
- Menstrual cramps (dysmenorrhea)
- Renal colic
- Functional bowel disorders
- Migraine headaches
- Muscle pain
- Pain after surgery
- Heavy bleeding during periods
Pharmacological Classification:
- Drotaverine: Antispasmodic
- Mefenamic Acid: Non-steroidal anti-inflammatory drug (NSAID)
Mechanism of Action:
Drotaverine acts as a direct smooth muscle relaxant by inhibiting phosphodiesterase enzyme, thereby reducing intracellular calcium levels and muscle contractions. Mefenamic acid inhibits prostaglandin synthesis, reducing pain and inflammation.
Alternate Names
No commonly used alternate generic names exist. Brand names include MIFESTA-DR and Genericart Drotaverine + Mefenamic Acid. Regional variations in brand names might exist.
How It Works
Pharmacodynamics: Drotaverine directly relaxes smooth muscles, reducing spasms. Mefenamic acid reduces pain and inflammation by inhibiting prostaglandin synthesis, particularly COX-1 and COX-2 enzymes.
Pharmacokinetics: Both drugs are absorbed orally. Mefenamic acid is highly protein-bound and metabolized in the liver. Drotaverine is also metabolized in the liver. Elimination pathways for both drugs are primarily through hepatic (liver) and renal (kidney) excretion. More research is needed to establish specific CYP enzyme involvement and details on their pharmacokinetics.
Mode of Action: Drotaverine inhibits phosphodiesterase enzyme, decreasing intracellular calcium, leading to smooth muscle relaxation. Mefenamic acid inhibits COX-1 and COX-2 enzymes, blocking prostaglandin synthesis, which mediates pain and inflammation.
Receptor binding, enzyme inhibition, or neurotransmitter modulation: Drotaverine: Phosphodiesterase inhibition. Mefenamic Acid: COX-1 and COX-2 enzyme inhibition.
Dosage
Standard Dosage
Adults:
One tablet (typically 80mg Drotaverine + 250mg Mefenamic Acid or 80mg Drotaverine + 500mg Mefenamic Acid), taken 2-3 times daily, with or after food. The maximum dose is typically one tablet of the higher strength formulation every six hours.
Children:
Not typically recommended for children under 12. For children over 12, the dosage and use must be determined by a doctor. Safety and efficacy have not been established in younger children. For children 6-12, some guidelines suggest ¼ or ½ tablet, 1-2 times daily for lower strengths and ½ or 1 tablet, 1 - 2 times daily for higher strengths.
Special Cases:
- Elderly Patients: Dosage should be adjusted based on renal and hepatic function. Lower doses are generally recommended.
- Patients with Renal Impairment: Use with caution. Dosage adjustment is necessary based on creatinine clearance. In severe renal impairment, contraindicated.
- Patients with Hepatic Dysfunction: Use with caution. Dose adjustment may be needed. Monitor liver function tests.
- Patients with Comorbid Conditions: Use with caution in patients with diabetes, cardiovascular disease, asthma, peptic ulcers, porphyria, or bleeding problems. Consider potential drug interactions.
Clinical Use Cases
Dosage for intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations is not specifically established for this combination and should be individualized based on the patient’s condition and the reason for administration. The drug is primarily used for pain and spasm relief in less acute settings.
Dosage Adjustments
Dose modifications are based on renal and hepatic function, age, and comorbidities. No specific guidelines for metabolic disorders or genetic polymorphisms are available for this specific combination.
Side Effects
Common Side Effects:
- Nausea
- Vomiting
- Diarrhea
- Dry mouth
- Heartburn
- Dizziness
- Headache
- Gastrointestinal disturbances
- Thirst
- Rashes
- Itching
- Flushing
- Abdominal pain
- Constipation
- Indigestion
Rare but Serious Side Effects:
- Allergic reactions (rash, itching, swelling)
- Stomach or intestinal bleeding
- Liver dysfunction
- Kidney dysfunction
- Cardiovascular events (heart attack, stroke)
Long-Term Effects:
Potential long-term effects are not well-established for this combination. Prolonged NSAID use can increase the risk of gastrointestinal issues and cardiovascular complications.
Adverse Drug Reactions (ADR):
Severe allergic reactions, gastrointestinal bleeding, liver or kidney damage, cardiovascular events require immediate medical attention.
Contraindications
- Hypersensitivity to drotaverine or mefenamic acid
- Asthma, especially aspirin-sensitive asthma
- Active or history of peptic ulcer
- Gastrointestinal bleeding
- Severe heart failure
- Coronary artery bypass graft (CABG) surgery period
- Severe hepatic or renal impairment
- Porphyria
- Bleeding disorders
- Neonates
- Pregnancy (especially third trimester)
- Breastfeeding
Drug Interactions
- Other NSAIDs (aspirin, ibuprofen): Increased risk of gastrointestinal side effects
- Anticoagulants (warfarin): Increased bleeding risk
- Antihypertensives: May reduce effectiveness
- Lithium, Fluoxetine, Sertraline, Duloxetine (antidepressants): Potential for increased side effects
- Digoxin: May increase digoxin levels
- Methotrexate: Increased toxicity
- Zidovudine: Increased risk of blood disorders
- Mifepristone: May reduce effectiveness
- Alcohol: Increased risk of dizziness, drowsiness, and gastrointestinal bleeding
Pregnancy and Breastfeeding
Pregnancy Safety Category: Not recommended during pregnancy, especially the third trimester, due to potential risks to the fetus (premature closure of ductus arteriosus).
Breastfeeding: Mefenamic acid is excreted in breast milk. The combination is not recommended during breastfeeding due to potential risks to the neonate.
Drug Profile Summary
- Mechanism of Action: Drotaverine relaxes smooth muscles; mefenamic acid inhibits prostaglandin synthesis.
- Side Effects: Nausea, vomiting, diarrhea, dizziness, headache, gastrointestinal issues. Rarely: allergic reactions, bleeding, organ damage.
- Contraindications: Hypersensitivity, asthma, peptic ulcer, bleeding disorders, severe heart, liver, or kidney disease, CABG surgery period, porphyria, pregnancy, breastfeeding.
- Drug Interactions: NSAIDs, anticoagulants, antihypertensives, some antidepressants, digoxin, methotrexate, zidovudine, mifepristone, alcohol.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Adults: One tablet 2-3 times/day. Adjust for elderly and those with renal or hepatic impairment. Not recommended for children under 12.
- Monitoring Parameters: Monitor for signs of gastrointestinal bleeding, liver or kidney dysfunction, and allergic reactions.
Popular Combinations
While this medication itself is a combination, it is sometimes prescribed with other medications for specific conditions. Always consult guidelines and exercise clinical judgment before combining medications.
Precautions
- Assess for allergies, renal/hepatic impairment, cardiovascular conditions, and other relevant comorbidities before prescribing.
- Monitor for adverse reactions.
- Caution in elderly patients.
- Avoid alcohol.
- Use cautiously in patients operating machinery or driving.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Drotaverine + Mefenamic Acid?
A: Adults: One tablet (80mg/250mg or 80mg/500mg) two to three times daily, with or after meals. Dosage should be adjusted for elderly patients and patients with renal or hepatic dysfunction. Not recommended for children under 12.
Q2: What are the primary uses of this combination medication?
A: It is primarily used to relieve pain and spasms related to smooth muscles, including menstrual cramps, abdominal cramps, and renal colic.
Q3: Can this drug be used during pregnancy or while breastfeeding?
A: No, it’s contraindicated during pregnancy, especially the third trimester, and breastfeeding due to potential harm to the fetus/neonate.
Q4: What are the common side effects patients should be aware of?
A: Common side effects include nausea, vomiting, diarrhea, dry mouth, dizziness, and headache.
Q5: Are there any serious side effects I should be concerned about?
A: Yes, although rare, serious side effects like allergic reactions, gastrointestinal bleeding, and liver or kidney dysfunction can occur. Patients should seek immediate medical help if they experience these.
Q6: What are the key drug interactions I should watch out for?
A: Significant interactions can occur with other NSAIDs, anticoagulants, antihypertensives, certain antidepressants, digoxin, methotrexate, zidovudine, and alcohol. Consult a comprehensive drug interaction resource for a detailed list.
Q7: Are there any specific precautions for elderly patients?
A: Yes, lower doses are generally recommended for elderly patients due to age-related decline in organ function. Close monitoring is advised.
Q8: What should I do if a patient misses a dose?
A: They should take the missed dose as soon as they remember, unless it is close to the next scheduled dose. They should never double the dose to catch up.
Q9: How does this medication differ from taking drotaverine or mefenamic acid alone?
A: The combination offers the synergistic benefit of muscle relaxation and pain/inflammation reduction, making it more effective for certain conditions than either drug used alone.
Q10: How should I counsel patients about taking this medicine?
A: Advise patients to take the medicine with or after food, inform them about potential side effects, emphasize the importance of adhering to the prescribed dose, and warn against using it with alcohol. Ensure they understand the contraindications, especially regarding pregnancy and breastfeeding. Encourage them to report any unusual symptoms immediately.
