Omeprazole(Prilosec) is a proton pump inhibitor used in the treatment of dyspepsia.

Ondansetron is a serotonin 5-HT3 receptor antagonist used mainly as anantiemetic (to treat nausea and vomiting), often following chemotherapy.

Orlistat is a drug designed to treat obesity. Orlistat's primary function is preventing the absorption of fats from the human diet by acting as a lipase inhibitor, thereby reducing caloric intake. Orlistat is intended for use in conjunction with a healthcare provider-supervised reduced-calorie diet.

Orotic acid (6-Carboxyuracil)

OSELTAMIVIR is an active (orally) inhibitor of the influenze virus neuraminidase and converted to the active acid metabolite in vivo.

Oxcarbazepine inhibits the binding of [3H]BTX to sodium channels with IC50 of 160 μM and also inhibits the influx of 22Na+ into rat brain synaptosomes with IC50 about 100 μM.

Oxfendazole

Oxibendazole

Oxonic acid potassium salt is an inhibitor of uricase, oxonic inhibits the phosphorylation of 5-FU to 5-fluorouridine-5'-monophosphate catalyzed by pyrimidine phosphoribosyl-transferase in a different manner from allopurinol in cell-free extracts and inta

Oxybutynin is also a possible treatment of hyperhidrosis (hyper-active sweating) .

Ozagrel HCl

Paliperidone (9-hydroxyrisperidone) is a dopamine antagonist of the atypical antipsychotic class of medications.

A serotonin 5-HT3 receptor antagonist used in the prevention and treatment of chemotherapy-induced nausea and vomiting (CINV). It is an antiemetic.

Pamidronate Disodium

Pamidronic acid

Pantoprazole sodium salt(SKF96022; Protonix) is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease.

PARECOXIB SODIUM

Paroxetine hydrochloride hemihydrate is a antidepressant agents known as selective serotonin-reuptake inhibitors (SSRIs).

Pefloxacin mesylate

Pemetrexed Disodium Hemipentahydrate

Pemirolast Potassium (BMY 26517) is a histamine H1 antagonist and mast cell stabilizer that acts as an antiallergic agent.

Penicillamine (Cuprimine)