Clinical data | |
---|---|
Trade names | Galliprant |
Routes of administration | By mouth |
ATCvet code | |
Legal status | |
Legal status | |
Pharmacokinetic data | |
Bioavailability | 6.6 L/kg, high volume of distribution |
Elimination half-life | 5.86 hours in horses |
Excretion | Kidney |
Identifiers | |
| |
CAS Number | |
PubChem CID | |
DrugBank | |
ChemSpider | |
UNII | |
CompTox Dashboard (EPA) | |
Chemical and physical data | |
Formula | C26H29N5O3S |
Molar mass | 491.61 g·mol−1 |
3D model (JSmol) | |
| |
|
Grapiprant, sold under the brand name Galliprant, is a small molecule drug that belongs in the piprant class. This analgesic and anti-inflammatory drug is primarily used as a pain relief for mild to moderate inflammation related to osteoarthritis in dogs. Grapiprant has been approved by the FDA's Center for Veterinary Medicine and was categorized as a non-cyclooxygenase inhibiting non-steroidal anti-inflammatory drug (NSAID) in March 2016. [3]
Preclinical studies also indicate that grapiprant is not only efficacious as a reliever of acute pain but also in chronic pain relief and inflammation. The effect of the drug is directly proportional to the dosage and its effects are comparable to human medications such as rofecoxib and piroxicam. [4]
Grapiprant has also been tested in humans, [5] and was researched to be used as pain control for inflammation associated with osteoarthritis.
Grapiprant is widely accepted in veterinary medicine due to its specific and targeted approach to pain management in dogs. The serum concentration of grapiprant is increased when used in conjunction with other drugs such as acetaminophen, albendazole, and alitretinoin.[ citation needed ]
Common side effects are intestinal related effects such as mild diarrhea, appetite loss, and vomiting. [6] It is theorised that it might lead to reduced tear production due to it being a sulfa-based medication,[ citation needed ] as well as decreased albumin levels. [7]
Grapiprant is indicated for the control of pain and inflammation associated with osteoarthritis in dogs. [2]
The effect of grapiprant can be explained through the function of prostaglandin E2, in which acts as a pro-inflammatory mediator of redness of the skin, edema and pain which are the typical signs of inflammation. The effect of PGE2 stems from its action through the four prostaglandin receptor subgroups EP1, EP2, EP3 and EP4, in which the prostaglandin EP4 receptor acts as the main intermediary of the prostaglandin-E2-driven inflammation. Grapiprant acts as a specific antagonist that binds and blocks the prostaglandin EP4 receptor, one out of the four prostaglandin E2 (PGE2) receptor subgroups. The EP4 receptor then mediates the prostaglandin-E2-elicited response to pain, and hence grapiprant was proven to be effective in the decrease of pain in several inflammatory pain models of rats. It was also proven to be effective in reducing osteoarthritis-related pain in humans, which serves as a proof for its mechanism of action. The approximate calculation for canine efficacy dose is between the range of 1.3 and 1.7 mg/kg, in conjunction with a methylcellulose suspending agent. Based on the calculations from the comparisons of binding affinity of grapiprant to the EP4 receptors of dogs, rats, and humans, the study of plasma and serum protein binding determinations, the effective doses determined in inflammation pain models of rats, and human-related clinical studies, it is evaluated that Grapiprant should be administered just once a day. The approved dose of the commercial Grapiprant tablet by the FDA for the pain relief and inflammation associated with osteoarthritis to dogs is reported to be 2 mg/kg a day. [8]
Studies in animals such as horses have shown the presence of grapiprant in serum 72 hours with a concentration >0.005 ng/mL after the initial administration of a dose of 2 mg/kg. Grapiprant is expeditiously absorbed and the reported serum concentration was reported to be 31.9 ng/ml in an amount of time of 1.5 hours. The actual body exposure to grapiprant after administration of one dose was shown to be 2000 ng·hr/mL. The degree and rate at which grapiprant is absorbed into the body, presents a mean bioavailability of 39%. A significant reduction in the bioavailability, concentration time and maximal concentration were reported to have occurred after food intake. [3] And thus, grapiprant is usually not administered with food as it will not be as efficient. [9]
The volume of distribution in cat studies was reported to be 918 ml/kg. [3]
Following an oral administration, the majority of the dose was metabolized within the first 72 hours. Equine studies have shown that grapiprant is present in urine 96 hours after the first administration of a dose of 2 mg/kg and has a concentration >0.005 ng/ml. From the excreted dose conducted in horses, it is found that 55%, 15% and 19% of the orally-administered dose was excreted in bile, urine, and faeces respectively. [3]
Safety studies conducted on grapiprant have demonstrated that it generally possesses an acceptable safety profile and a wide safety margin in veterinary studies. [10] In animal studies, a research on 2.5–12 times overdose was conducted for grapiprant and the study resulted in soft stool and mucus-filled faeces, occasional bloody stools and emesis.
Phenylbutazone, often referred to as "bute", is a nonsteroidal anti-inflammatory drug (NSAID) for the short-term treatment of pain and fever in animals.
Glucosamine (C6H13NO5) is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of two polysaccharides, chitosan and chitin. Glucosamine is one of the most abundant monosaccharides. Produced commercially by the hydrolysis of shellfish exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat, glucosamine has many names depending on country.
Meloxicam, sold under the brand name Mobic among others, is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation in rheumatic diseases and osteoarthritis. It is used by mouth or by injection into a vein. It is recommended that it be used for as short a period as possible and at a low dose.
Carprofen is a nonsteroidal anti-inflammatory drug (NSAID) of the carbazole and propionic acid class that was previously for use in humans and animals but is now only available to veterinarians for prescribing as a supportive treatment for various conditions in animals. Carprofen reduces inflammation by inhibition of COX-1 and COX-2; its specificity for COX-2 varies from species to species. Marketed under many brand names worldwide, carprofen is used as a treatment for inflammation and pain, including joint pain and postoperative pain.
Diflunisal is a salicylic acid derivative with analgesic and anti-inflammatory activity. It was developed by Merck Sharp & Dohme in 1971, as MK647, after showing promise in a research project studying more potent chemical analogs of aspirin. It was first sold under the brand name Dolobid, marketed by Merck & Co., but generic versions are now widely available. It is classed as a nonsteroidal anti-inflammatory drug (NSAID) and is available in 250 mg and 500 mg tablets.
Prostaglandin E2 (PGE2), also known as dinoprostone, is a naturally occurring prostaglandin with oxytocic properties that is used as a medication. Dinoprostone is used in labor induction, bleeding after delivery, termination of pregnancy, and in newborn babies to keep the ductus arteriosus open. In babies it is used in those with congenital heart defects until surgery can be carried out. It is also used to manage gestational trophoblastic disease. It may be used within the vagina or by injection into a vein.
A prostaglandin antagonist is a hormone antagonist acting upon one or more prostaglandins, a subclass of eicosanoid compounds which function as signaling molecules in numerous types of animal tissues.
Tepoxalin, sold under the brand name Zubrin among others, is a non-steroidal anti-flammatory drug (NSAIDs) generally used in veterinary medicine to reduce swelling in animals with osteoarthritis. In rare circumstances, tepoxalin can also be used in human pharmacology to relieve pain caused by musculoskeletal conditions such as arthritis and hip dysplasia.
Prostaglandin E2 receptor 4 (EP4) is a prostaglandin receptor for prostaglandin E2 (PGE2) encoded by the PTGER4 gene in humans; it is one of four identified EP receptors, the others being EP1, EP2, and EP3, all of which bind with and mediate cellular responses to PGE2 and also, but generally with lesser affinity and responsiveness, certain other prostanoids (see Prostaglandin receptors). EP4 has been implicated in various physiological and pathological responses in animal models and humans.
Prostaglandin E2 receptor 1 (EP1) is a 42kDa prostaglandin receptor encoded by the PTGER1 gene. EP1 is one of four identified EP receptors, EP1, EP2, EP3, and EP4 which bind with and mediate cellular responses principally to prostaglandin E2) (PGE2) and also but generally with lesser affinity and responsiveness to certain other prostanoids (see Prostaglandin receptors). Animal model studies have implicated EP1 in various physiological and pathological responses. However, key differences in the distribution of EP1 between these test animals and humans as well as other complicating issues make it difficult to establish the function(s) of this receptor in human health and disease.
Prostaglandin E2 receptor 2, also known as EP2, is a prostaglandin receptor for prostaglandin E2 (PGE2) encoded by the human gene PTGER2: it is one of four identified EP receptors, the others being EP1, EP3, and EP4, which bind with and mediate cellular responses to PGE2 and also, but with lesser affinity and responsiveness, certain other prostanoids (see Prostaglandin receptors). EP has been implicated in various physiological and pathological responses.
Prostaglandin EP3 receptor (EP3, 53kDa), is a prostaglandin receptor for prostaglandin E2 (PGE2) encoded by the human gene PTGER3; it is one of four identified EP receptors, the others being EP1, EP2, and EP4, all of which bind with and mediate cellular responses to PGE2 and also, but generally with lesser affinity and responsiveness, certain other prostanoids (see Prostaglandin receptors). EP has been implicated in various physiological and pathological responses.
Pravadoline (WIN 48,098) is an anti-inflammatory and analgesic drug with an IC50 of 4.9 μM and a Ki of 2511 nM at CB1, related in structure to nonsteroidal anti-inflammatory drugs (NSAIDs) such as indometacin. It was developed in the 1980s as a new antiinflammatory and prostaglandin synthesis inhibitor, acting through inhibition of the enzyme cyclooxygenase (COX).
Antalarmin (CP-156,181) is a drug that acts as a CRH1 antagonist.
Maropitant (INN; brand name: Cerenia, used as maropitant citrate (USAN), is a neurokinin-1 (NK1) receptor antagonist developed by Zoetis specifically for the treatment of motion sickness and vomiting in dogs. It was approved by the FDA in 2007, for use in dogs and in 2012, for cats.
Atipamezole, sold under the brand name Antisedan among others, is a synthetic α2 adrenergic receptor antagonist used for the reversal of the sedative and analgesic effects of dexmedetomidine and medetomidine in dogs. Its reversal effect works by competing with the sedative for α2-adrenergic receptors and displacing them. It is mainly used in veterinary medicine, and while it is only licensed for dogs and for intramuscular use, it has been used intravenously, as well as in cats and other animals(intravenous use in cats and dogs is not recommended due to the potential for cardiovascular collapse. This occurs due to profound hypotension caused by reversal of the alpha 1 effects while the reflex bradycardia is still in effect.). There is a low rate of side effects, largely due to atipamezole's high specificity for the α2-adrenergic receptor. Atipamezole has a very quick onset, usually waking an animal up within 5 to 10 minutes.
Lomerizine (INN) is a diphenylpiperazine class L-type and T-type calcium channel blocker. This drug is currently used clinically for the treatment of migraines, while also being used experimentally for the treatment of glaucoma and optic nerve injury.
Setipiprant (INN; developmental code names ACT-129968, KYTH-105) is an investigational drug developed for the treatment of asthma and scalp hair loss. It was originally developed by Actelion and acts as a selective, orally available antagonist of the prostaglandin D2 receptor 2 (DP2). The drug is being developed as a novel treatment for male pattern baldness by Allergan.
The prostaglandin E2 (PGE2) receptors are G protein-coupled receptors that bind and are activated by prostaglandin E2. They are members of the prostaglandin receptors class of receptors and include the following Protein isoforms:
Polysulfated glycosaminoglycan (PSGAG), sold under the brand name Adequan, is an injectable drug for dogs and horses that is used to alleviate the limpness, pain, and lowered range of motion caused by arthritis. It is made of repeat disaccharide units (comprising hexosamine and hexuronic acid), and is similar to glycosaminoglycans already present in the cartilage; PSGAG thus easily integrates itself there. In vitro studies have shown it to inhibit the enzymes that degrade cartilage and bone, as well as suppress inflammation and stimulate the synthesis of replacement cartilage. While it can cause an increased risk of bleeding, it is relatively safe and has a high LD50. PSGAG is one of the most widely prescribed joint treatments for horses.