Usage
Hyoscine butylbromide + Mefenamic Acid is prescribed for the treatment of menstrual pain and cramps associated with primary dysmenorrhea. It is also used to alleviate symptoms of premenstrual syndrome (PMS) and manage excessively heavy periods (menorrhagia).
Pharmacological Classification:
- Hyoscine butylbromide: Anticholinergic, antispasmodic
- Mefenamic acid: Non-steroidal anti-inflammatory drug (NSAID), analgesic
Mechanism of Action: This combination medication works through two distinct mechanisms:
- Hyoscine butylbromide: Relaxes the smooth muscles of the uterus, reducing spasms and cramping.
- Mefenamic acid: Inhibits cyclooxygenase (COX) enzymes, reducing the production of prostaglandins, which are chemical messengers that cause pain and inflammation.
Alternate Names
While the generic name is Hyoscine butylbromide + Mefenamic Acid, the combination is marketed under various brand names, including Hyocimax MF and Buscopan Venus (when combined with paracetamol). There are no widely recognized international or regional variations for this specific combination.
How It Works
Pharmacodynamics:
- Hyoscine butylbromide: Acts as an anticholinergic agent, primarily targeting muscarinic receptors in the smooth muscle of the gastrointestinal and genitourinary tracts. It inhibits acetylcholine binding, leading to muscle relaxation and reduced spasms.
- Mefenamic acid: A non-selective COX inhibitor, reducing the production of prostaglandins involved in pain and inflammation.
Pharmacokinetics:
- Hyoscine butylbromide: Poorly absorbed orally (around 8% bioavailability). Metabolized in the liver and primarily excreted in the feces. It has a relatively short half-life.
- Mefenamic acid: Well-absorbed orally. Metabolized in the liver primarily by CYP2C9. Excreted mostly in the urine and bile.
Receptor binding, enzyme inhibition, or neurotransmitter modulation:
- Hyoscine butylbromide: Muscarinic receptor antagonist (specifically M3 subtype in the gut).
- Mefenamic acid: COX-1 and COX-2 enzyme inhibitor.
Elimination pathways:
- Hyoscine butylbromide: Hepatic metabolism with predominantly fecal excretion.
- Mefenamic acid: Hepatic metabolism, predominantly renal and biliary excretion.
Dosage
Standard Dosage
Adults: 1-2 tablets (each containing Hyoscine butylbromide 10 mg and Mefenamic acid 250 mg), three times daily. The total daily dose should not exceed 6 tablets.
Children: Not recommended for children under 12 years of age. For adolescents 12-18 years, dosage should be individualized based on weight and clinical condition. Pediatric safety must be carefully considered due to the potential for adverse effects.
Special Cases:
- Elderly Patients: Start with lower doses due to potential age-related decrease in renal and hepatic function. Titrate upwards as needed and tolerated.
- Patients with Renal Impairment: Dose adjustment may be needed depending on the degree of impairment. Consult renal function tests.
- Patients with Hepatic Dysfunction: Dose adjustment may be necessary due to decreased metabolism. Liver function tests should guide dosage.
- Patients with Comorbid Conditions: Exercise caution in patients with glaucoma, urinary retention, gastrointestinal obstruction, myasthenia gravis, cardiovascular disease, and asthma.
Clinical Use Cases
This drug combination is not typically used in clinical settings like intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations. Its usage is primarily limited to managing menstrual pain.
Dosage Adjustments
Dosage adjustments are based on patient-specific factors such as renal or hepatic impairment and response to therapy. Close monitoring is needed for elderly patients and those with comorbid conditions.
Side Effects
Common Side Effects
Nausea, vomiting, dry mouth, heartburn, dizziness, drowsiness, constipation.
Rare but Serious Side Effects
Allergic reactions (rash, itching, swelling), gastrointestinal bleeding, Stevens-Johnson syndrome, toxic epidermal necrolysis.
Long-Term Effects
With prolonged use, especially at higher doses, there is a risk of gastrointestinal issues like ulcers and bleeding.
Adverse Drug Reactions (ADR)
Anaphylaxis, angioedema, severe skin reactions, hepatotoxicity, renal impairment.
Contraindications
- Hypersensitivity to hyoscine butylbromide, mefenamic acid, or any component of the formulation.
- Glaucoma (especially narrow-angle glaucoma).
- Myasthenia gravis.
- Gastrointestinal obstruction (e.g., paralytic ileus, megacolon).
- Urinary retention (especially in patients with prostatic hypertrophy).
- Severe hepatic impairment.
- Pregnancy (especially first and third trimesters).
- Children under 12 years of age.
Drug Interactions
- Anticholinergic drugs: Additive anticholinergic effects (e.g., increased dry mouth, blurred vision, constipation).
- NSAIDs: Increased risk of gastrointestinal bleeding.
- Anticoagulants: Increased risk of bleeding.
- Alcohol: Increased drowsiness and dizziness, increased risk of stomach bleeding.
- Antidepressants (e.g., tricyclic antidepressants, SSRIs): Additive anticholinergic effects.
Pregnancy and Breastfeeding
- Pregnancy: Contraindicated, especially in the first and third trimesters, due to potential risks to the fetus (premature closure of the ductus arteriosus, fetal renal dysfunction).
- Breastfeeding: Not recommended as the drug may be excreted in breast milk and could have adverse effects on the infant.
Drug Profile Summary
- Mechanism of Action: Hyoscine butylbromide: Antispasmodic; Mefenamic acid: Analgesic, anti-inflammatory
- Side Effects: Nausea, vomiting, dry mouth, heartburn, dizziness, drowsiness.
- Contraindications: Hypersensitivity, glaucoma, myasthenia gravis, gastrointestinal obstruction, urinary retention, severe hepatic impairment, pregnancy.
- Drug Interactions: Anticholinergics, NSAIDs, anticoagulants, alcohol.
- Pregnancy & Breastfeeding: Contraindicated in pregnancy, not recommended during breastfeeding.
- Dosage: 1-2 tablets three times daily (max 6 tablets/day).
- Monitoring Parameters: Renal and hepatic function, signs of gastrointestinal bleeding, allergic reactions.
Popular Combinations
Not applicable for this combination.
Precautions
- General Precautions: Assess for allergies, renal/hepatic impairment, gastrointestinal conditions, and cardiovascular disease before initiating therapy.
- Specific Populations: See “Dosage - Special Cases”.
- Lifestyle Considerations: Avoid alcohol; caution with driving or operating machinery due to potential drowsiness.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Hyoscine butylbromide + Mefenamic Acid?
A: The usual adult dose is 1-2 tablets three times daily. The maximum daily dose is 6 tablets.
Q2: Can this combination be used during pregnancy?
A: No, it’s contraindicated during pregnancy, especially in the first and third trimesters.
Q3: Is it safe to breastfeed while taking this medicine?
A: It’s generally not recommended as it may pass into breast milk and affect the infant.
Q4: What are the common side effects?
A: Common side effects include nausea, vomiting, dry mouth, heartburn, dizziness, and drowsiness.
Q5: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember unless it’s nearly time for the next dose. Don’t take a double dose to make up for a missed one.
Q6: Can I drink alcohol while taking this medication?
A: It’s advisable to avoid alcohol as it can exacerbate side effects like drowsiness and dizziness and increase the risk of stomach bleeding.
Q7: What should I do if my symptoms don’t improve?
A: Consult your doctor if your menstrual pain doesn’t improve or worsens after a few days of treatment.
Q8: Can I drive while taking this medicine?
A: Exercise caution as this combination may cause drowsiness and dizziness. Avoid driving if you experience these side effects.
Q9: Are there any serious side effects I should be aware of?
A: Although rare, serious side effects can include allergic reactions and gastrointestinal bleeding. Seek immediate medical attention if these occur.
