Last reviewed 2026-04-20 · How we verify

Synalgos-Dc (DIHYDROCODEINE)

Synalgos-Dc, marketed by Caraco, is a dihydrocodeine-based analgesic positioned for moderate to moderately severe pain relief, competing in a crowded market of opioid analgesics. Its key strength lies in its mechanism of action, which effectively mimics natural pain-relieving chemicals by binding to opioid receptors in the brain, providing reliable pain management. The primary risk to Synalgos-Dc is the expiration of its key composition patent in 2028, which could lead to increased competition from generic alternatives.

At a glance

Approved indications

• Moderate to moderately severe pain relief

Boxed warnings

• WARNING: Death Related to Ultra-Rapid Metabolism of Codeine to Morphine Respiratory depression and death have occurred in children who received codeine following tonsillectomy and/or adenoidectomy and had evidence of being ultra-rapid metabolizers of codeine due to a CYP2D6 polymorphism. Hepatotoxicity Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4000 milligrams per day, and often involve more than one acetaminophen containing product.

Common side effects

• Respiratory depression
• Orthostatic hypotension
• Cough suppression
• Confusion
• Diarrhea
• Miosis
• Abdominal pain
• Dry mouth
• Indigestion
• Anorexia
• Spasm of biliary tract
• Urinary retention

Drug interactions

• Other Central Nervous System Depressants (opioid analgesics, sedatives, hypnotics, muscle relaxants, general anesthetics, centrally acting anti-emetics, phenothiazines, tranquilizers, alcohol)
• Monoamine Oxidase Inhibitors
• Mixed Agonist/Antagonist Opioid Analgesics (pentazocine, nalbuphine, butorphanol, buprenorphine)
• Alcohol
• Anticonvulsants that induce hepatic microsomal enzymes (phenytoin, barbiturates, carbamazepine), isoniazide
• Warfarin and indandione-derivative anticoagulants
• Phenothiazines
• Beta-adrenergic stimulating agents
• Disulfiram
• Phenobarbital, Aspirin
• Quinolones (ciprofloxacin)

Key clinical trials

• Comparison of the Efficacy, Tolerability and Safety of actiTENS to Those of Level 2 Analgesic Treatments. (NA)
• Randomized Controlled Double Blind Trial of Short vs Long Acting Dihydrocodeine in Chronic Non-malignant Pain (PHASE4)
• A Study to Evaluate the Safety and Effectiveness of Fentanyl-TTS Compared to Weak Opioids in Patients With Moderate to Severe Chronic Cancer Pain Previously Treated With NSAIDS (Non-steroidal Anti-inflammatory Drugs). (PHASE4)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Synalgos-Dc CI brief — competitive landscape report
• Synalgos-Dc updates RSS · CI watch RSS
• Caraco portfolio CI