Cinchophen and Prednisolone
2-phenylquinoline-4-carboxylic acid; 11beta,17,21-trihydroxypregna-1,4-diene-3,20-dione
Also known as: PLT tablets · Prednoleucotropin · Cinchophenum · Quinophan · Atophan
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Dosing by species
Dosing data for this drug is not yet available in the VetSheet formulary. Every other section below is complete. Consult the current product label before prescribing.
Overview
Combination of cinchophen (an older non-steroidal anti-inflammatory drug) and prednisolone (a glucocorticoid). Historically used for the management of osteoarthritis and inflammatory conditions in dogs.
Clinical Pearl: The concurrent use of an NSAID and a corticosteroid is generally contraindicated in modern veterinary practice due to a significantly compounded risk of severe gastrointestinal ulceration and perforation. This is a legacy product (e.g., PLT tablets) and requires extremely careful monitoring, particularly for hepatotoxicity associated with cinchophen.
Mechanism of action
Cinchophen acts as an NSAID by inhibiting cyclooxygenase (COX) enzymes → decreased synthesis of pro-inflammatory prostaglandins.
Prednisolone is a synthetic glucocorticoid that binds to cytosolic receptors → alters gene transcription → inhibits phospholipase A2 via lipocortin → decreases arachidonic acid release and reduces inflammatory cytokines.
Safety & warnings
Contraindications
- Pre-existing gastrointestinal ulceration
- Hepatic impairment
- Renal impairment
- Concurrent use of other NSAIDs or corticosteroids
Adverse effects
- Gastrointestinal ulceration
- Hepatotoxicity
- Polyuria (PU)
- Polydipsia (PD)
- Polyphagia
- Vomiting
- Diarrhea
- Melena
Precautions
Animals must be strictly monitored for signs of gastrointestinal ulceration (e.g., melena, vomiting blood) and deterioration in liver function.
Warning: At the end of treatment, the dose must be tapered gradually to prevent Addisonian crisis due to adrenal suppression from the prednisolone component.
Drug interactions
Increased risk of severe GI ulceration and perforation
Increased risk of severe GI ulceration and immunosuppression
Synergistic toxicity leading to severe gastrointestinal ulceration and perforation.
Synergistic toxicity leading to severe gastrointestinal ulceration and perforation.
Increased risk of nephrotoxicity and gastrointestinal ulceration.
Monitoring
- Clinical signs of GI ulceration (vomiting, melena, anorexia)
- Liver function tests (ALT, ALP, AST, Bilirubin)
- Renal parameters (BUN, Creatinine)
Pharmacokinetics
Absorption
Well absorbed orally.
Distribution
Widely distributed.
Metabolism
Hepatic metabolism (both components). Cinchophen is known for potential hepatotoxic metabolites.
Elimination
Renal and biliary excretion.
Overdose
Overdosage significantly increases the risk of gastrointestinal perforation, severe hepatotoxicity, and acute renal failure. Treatment is supportive, including GI protectants (e.g., omeprazole, sucralfate), intravenous fluid therapy, and hepatoprotectants.
Available products
Formulations
- Oral tablet: 200 mg cinchophen / 1 mg prednisolone
Veterinary
- PLT tablets (200 mg cinchophen / 1 mg prednisolone)
Regulatory status
Cinchophen is largely obsolete in the US due to hepatotoxicity.
Available as legacy combination products like PLT in some regions.
Historically available as PLT tablets (POM-V), though clinical use has drastically declined in favor of safer alternatives.
No regulatory data for: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature in a tightly closed container, protected from light and moisture. Normal safety and handling precautions should be observed.
Client information
Administer strictly as directed by your veterinarian, ideally with food.
Important: Watch closely for signs of stomach ulcers, such as vomiting (especially with blood or looking like coffee grounds), dark tarry stools, or loss of appetite.
Due to the steroid component, you may notice increased thirst, urination, and appetite. Do not stop this medication abruptly unless instructed by your vet, as the dose usually needs to be tapered slowly.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.