A fixed-dose combination (FDC) of an antispasmodic (antimuscarinic) and an analgesic-antipyretic. Hyoscine butylbromide is a quaternary ammonium derivative that acts peripherally to relieve smooth muscle spasm in the gastrointestinal, biliary, and genitourinary tracts. Paracetamol (acetaminophen) is a centrally and peripherally acting analgesic and antipyretic with minimal anti-inflammatory activity. This combination is primarily used for the symptomatic relief of pain associated with smooth muscle spasm, such as in renal or biliary colic, and dysmenorrhea.
Adult: One tablet (Hyoscine butylbromide 10mg + Paracetamol 500mg) orally every 6-8 hours as needed for pain. Maximum: 4 tablets in 24 hours.
Note: Take with or after food to minimize potential gastric discomfort. Swallow the tablet whole with a glass of water. Do not crush or chew. The tablet can be taken at the first sign of spastic pain. For procedural use, administer 30-60 minutes before the procedure.
Hyoscine butylbromide is a competitive antagonist at muscarinic acetylcholine receptors (M1, M2, M3) located on smooth muscle cells in the walls of hollow visceral organs. By blocking acetylcholine, it inhibits parasympathetic nerve impulses, leading to smooth muscle relaxation and reduction of spasm, motility, and secretions. Paracetamol's exact mechanism is not fully elucidated but is believed to involve inhibition of prostaglandin synthesis (cyclooxygenase, COX) primarily within the central nervous system (COX-3 inhibition theory) and modulation of the endogenous cannabinoid and serotonergic systems, resulting in analgesia and antipyresis with weak peripheral anti-inflammatory effects.
Pregnancy: Category B (US FDA). Hyoscine butylbromide crosses the placenta minimally due to its quaternary structure. Paracetamol is considered the analgesic of choice for mild to moderate pain during pregnancy when indicated. Use only if clearly needed and at the lowest effective dose for the shortest duration. Avoid in the third trimester for prolonged use due to theoretical risk of premature ductus arteriosus closure (paracetamol).
Driving: May cause dizziness, drowsiness, and blurred vision. Patients should be cautioned against driving or operating heavy machinery until they know how the medication affects them.
| Other Anticholinergics (e.g., Atropine, Dicyclomine, Tricyclic Antidepressants, Antipsychotics) | Additive anticholinergic effects (dry mouth, constipation, urinary retention, confusion, tachycardia). | Major |
| Warfarin and other Coumarin Anticoagulants | Paracetamol, especially with prolonged high doses (>1.3g/day for several days), may potentiate anticoagulant effect, increasing INR and risk of bleeding. | Moderate |
| Enzyme Inducers (e.g., Rifampicin, Phenytoin, Carbamazepine, Phenobarbital, Alcohol (chronic)) | Increased metabolism of paracetamol to its toxic metabolite (NAPQI), raising the risk of hepatotoxicity even at therapeutic doses. | Major |
| Domperidone, Metoclopramide | Antagonistic effects on GI motility. Hyoscine reduces motility, while prokinetics increase it. | Moderate |
| Cholestyramine | Reduces absorption of paracetamol if taken within 1 hour. Administer at least 2 hours apart. | Moderate |
| Isoniazid | May increase the risk of paracetamol hepatotoxicity. | Moderate |
| 5-HT3 Antagonists (e.g., Ondansetron) | Increased risk of constipation. | Minor |
| Levodopa | Hyoscine may reduce gastric absorption of levodopa. | Moderate |
| Alcohol (Acute, excessive intake) | Synergistic CNS depression with hyoscine; significantly increases risk of paracetamol-induced hepatotoxicity. | Major |
Same composition (Hyoscine butylbromide (10mg) + Paracetamol (500mg)), different brands: