1. Clinical Overview
A fixed-dose combination (FDC) analgesic-antispasmodic medication widely used in India for the management of moderate to severe pain associated with smooth muscle spasm, particularly in conditions like renal colic, biliary colic, and dysmenorrhea. Dicyclomine provides anticholinergic and direct smooth muscle relaxant effects, Diclofenac is a potent NSAID providing anti-inflammatory and analgesic action, and Paracetamol is a centrally-acting analgesic and antipyretic. This combination offers a synergistic effect for pain relief in spasmodic conditions.
| Onset | Duration | Bioavailability |
|---|---|---|
| Dicyclomine: 1-2 hours (oral); Diclofenac: 30-60 minutes (oral); Paracetamol: 30-60 minutes (oral). | Dicyclomine: 4-6 hours; Diclofenac: 8-12 hours; Paracetamol: 4-6 hours. | Dicyclomine: ~67-73%; Diclofenac: ~50-60%; Paracetamol: ~88%. |
2. Mechanism of Action
The combination exerts a multi-modal action on pain pathways. Dicyclomine acts as a competitive antagonist at muscarinic (M1, M3) receptors in visceral smooth muscle, reducing acetylcholine-mediated contractions. It also has a direct papaverine-like smooth muscle relaxant effect. Diclofenac inhibits both cyclooxygenase-1 (COX-1) and COX-2 enzymes, with a higher affinity for COX-2, thereby reducing the synthesis of prostaglandins (PGs), thromboxanes, and prostacyclins from arachidonic acid. This provides anti-inflammatory, analgesic, and antipyretic effects. Paracetamol's exact mechanism is not fully understood but is believed to involve central inhibition of prostaglandin synthesis (likely COX-2 and COX-3 isoforms) and modulation of the serotonergic and cannabinoid systems, providing analgesic and antipyretic effects with minimal peripheral anti-inflammatory activity.
3. Indications & Uses
- Renal colic (Ureteric colic)
- Biliary colic
- Severe primary dysmenorrhea (Menstrual cramps)
- Pain associated with intestinal colic (e.g., Irritable Bowel Syndrome - IBS during flare-ups)
4. Dosage & Administration
Adult Dosage: One tablet every 6-8 hours, after food. Maximum: 3 tablets in 24 hours. Duration should not exceed 5-7 days without medical supervision.
Administration: Take with or immediately after a meal or a glass of milk to minimize gastrointestinal irritation. Swallow the tablet whole with a full glass of water. Do not crush or chew. Do not lie down for at least 10 minutes after taking the tablet.
5. Side Effects
Common side effects may include:
- Nausea
- Dry mouth (Xerostomia)
- Dizziness/Drowsiness
- Heartburn/Epigastric discomfort
- Constipation
- Blurred vision (mild)
- Headache
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Warfarin/Acenoocumarol | Increased risk of bleeding due to Diclofenac's antiplatelet effect and protein binding displacement. | Major |
| Aspirin/other NSAIDs | Increased risk of GI toxicity (ulcers, bleeding) with no added therapeutic benefit. | Major |
| Lithium | Diclofenac can decrease renal clearance of Lithium, leading to toxicity. | Major |
| Methotrexate | Diclofenac may reduce renal clearance of Methotrexate, increasing risk of bone marrow suppression. | Major |
| Diuretics (Furosemide, Thiazides) | Reduced diuretic and antihypertensive efficacy; increased risk of renal impairment. | Moderate |
| ACE Inhibitors (Ramipril, Enalapril) / ARBs (Losartan) | Reduced antihypertensive effect; increased risk of renal impairment. | Moderate |
| Corticosteroids (Prednisolone) | Markedly increased risk of GI ulceration and bleeding. | Major |
| Anticholinergics (Amitriptyline, Oxybutynin) | Additive anticholinergic side effects (dry mouth, constipation, urinary retention, confusion) with Dicyclomine. | Moderate |
| Anticoagulants (Heparin, DOACs) | Increased bleeding risk. | Major |
| Antidiabetics (Sulfonylureas) | Diclofenac may potentiate hypoglycemic effect. | Moderate |
| Cyclosporine/Tacrolimus | Increased risk of nephrotoxicity. | Major |
| Quinolone antibiotics (Ciprofloxacin) | Increased risk of CNS stimulation and seizures. | Moderate |
| Cholestyramine | Reduces absorption of Paracetamol if taken within 1 hour. | Moderate |
| Isoniazid | May increase risk of Paracetamol hepatotoxicity by inducing CYP2E1. | Moderate |
| Alcohol (Chronic use) | Increases risk of Paracetamol hepatotoxicity and Diclofenac-induced GI bleeding. | Major |
7. Patient Counselling
- DO take with food or milk to avoid stomach upset.
- DO inform your doctor about all other medicines you are taking, including OTC drugs and supplements.
- DO drink plenty of fluids while on this medication.
- DO report any signs of black/tarry stools, vomiting blood, unusual fatigue, or yellowing of skin/eyes immediately.
- DONT take more than the prescribed dose or for longer than directed.
- DONT crush or chew the tablet.
- DONT consume alcohol while on this medication.
- DONT take other products containing Paracetamol (e.g., cold & flu remedies) to avoid overdose.
- DONT use for fever or headache unless specifically prescribed for the associated spasm.
8. Toxicology & Storage
Overdose: Dicyclomine: Flushing, hyperthermia, tachycardia, respiratory failure, coma, convulsions. Diclofenac: Nausea, vomiting, epigastric pain, GI bleeding, headache, dizziness, tinnitus, seizures, acute renal failure. Paracetamol: Stage 1 (0-24h): Nausea, vomiting, malaise. Stage 2 (24-72h): Right upper quadrant pain, elevated LFTs. Stage 3 (72-96h): Peak hepatotoxicity (jaundice, coagulopathy, encephalopathy). Stage 4 (4d-2w): Recovery or fatal hepatic necrosis.
Storage: Store below 30°C, in a cool, dry place. Protect from light and moisture. Keep out of reach and sight of children. Do not use after the expiry date printed on the pack.