Understanding the Various Names for Ponazuril
When discussing veterinary medications, it is common to encounter drugs with multiple names. This can include generic names, brand names, and chemical or derivative names. For ponazuril, a key antiprotozoal medication, understanding these different monikers is crucial for proper identification and context in veterinary practice.
The Brand Name: Marquis®
The most widely recognized name for ponazuril, particularly in the United States, is the brand name Marquis®. Originally manufactured by Bayer Animal Health and now produced by Boehringer Ingelheim, this is the brand that received FDA approval for the treatment of Equine Protozoal Myeloencephalitis (EPM). Marquis is sold as an oral paste, and its active ingredient is ponazuril. For horse owners and veterinarians, Marquis is the common term used to refer to this specific formulation of the drug.
The Chemical Name: Toltrazuril Sulfone
On a chemical level, ponazuril is also known as toltrazuril sulfone. This name describes its relationship to another antiprotozoal drug, toltrazuril. Ponazuril is an active metabolite of toltrazuril, meaning it is the form that toltrazuril is converted into within the body to exert its therapeutic effects. This is an important distinction, as while the two drugs are similar, they are not identical. Toltrazuril is often sold under a different brand name, such as Baycox®, and is used for similar but distinct applications. The chemical relationship between these two drugs is a significant detail for pharmacists and veterinarians when considering compounded or extra-label uses.
Other Monikers
In addition to its main brand and chemical names, ponazuril may also be referred to by other less common or former brand names, such as Ponalrestat. However, Marquis and toltrazuril sulfone are the most prevalent alternative names encountered in clinical and pharmacological discussions. For many practitioners, the context of the animal and the specific parasitic infection will determine which name is used, with Marquis being most common for horses and generic names often used for small animal or off-label applications.
What Ponazuril is Used For
Ponazuril's primary purpose is as an antiprotozoal agent, targeting specific single-celled organisms that cause disease in animals. Its FDA-approved use is for treating EPM in horses, a neurological disease caused by the protozoan Sarcocystis neurona. However, veterinarians often use the drug in an extra-label capacity to treat other protozoal infections in different species.
Common Extra-label Uses:
- Coccidiosis: An intestinal parasitic infection affecting various animals, including dogs, cats, rabbits, and poultry.
- Toxoplasma spp.: A parasite known to cause toxoplasmosis, particularly in cats and other species.
- Neospora spp.: Protozoa that can cause neurological disease in dogs.
- Eimeria spp.: Another type of coccidia affecting poultry and livestock.
Ponazuril vs. Toltrazuril
Due to their chemical relationship, ponazuril and toltrazuril are often discussed together. While ponazuril is a metabolite of toltrazuril, veterinarians may choose one over the other depending on the species and type of infection. Some studies suggest ponazuril may be more effective for certain conditions, particularly in small, sensitive animals like kittens with coccidiosis.
| Feature | Ponazuril | Toltrazuril |
|---|---|---|
| Primary Brand Name | Marquis® | Baycox® |
| Chemical Name | Toltrazuril Sulfone | Toltrazuril |
| Regulatory Status (US) | FDA approved for EPM in horses | Not FDA-approved in the US; commonly used in extra-label applications |
| Formulation | Oral paste (for horses), compounded liquid suspension (other species) | Oral liquid suspension |
| Common Use | EPM in horses, extra-label for other protozoal infections | Extra-label for various coccidia infections |
How Ponazuril Works
The mechanism of action for ponazuril involves disrupting the metabolic processes of protozoa. Specifically, it is thought to inhibit enzyme systems and decrease the synthesis of pyrimidines, which are crucial components for the parasites' DNA and RNA. This action is specific to the apicomplexan group of protozoa because the drug targets a unique organelle, the apicoplast. This targeted approach makes the drug effective against the parasites while being relatively safe for the host animal's cells. For the treatment of EPM in horses, the ability of ponazuril to cross the blood-brain barrier is a critical feature, allowing it to reach the site of the neurological infection.
Conclusion
In summary, while the generic name is ponazuril, the most recognized brand name is Marquis®. The chemical name is toltrazuril sulfone, which highlights its relationship as an active metabolite of the drug toltrazuril. This drug is primarily known for treating EPM in horses but has wide-ranging extra-label uses for coccidiosis and other protozoal infections in numerous animal species. When a veterinarian or pet owner refers to ponazuril, they are most likely speaking of Marquis paste for horses, but the chemical designation is an important piece of pharmacological information, especially when considering compounded formulations. For detailed information on its approved uses, one can consult the official FDA document on the drug.(https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/698)
