| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| Obinutuzumab Octocog alfa Octopamine Octreotide Ofloxacin Olanzapine Olanzapine + Fluoxetine Olaparib Olive oil Olmesartan Olmesartan + Hydrochlorothiazide Olodaterol Olopatadine Olsalazine Omacetaxine mepesuccinate Omalizumab Omega-3 triglycerides Omeprazole Omoconazole Ondansetron | Opipramol Oprelvekin Orciprenaline Orgotein Orlistat Ormeloxifene Ornidazole Orphenadrine Oseltamivir Osimertinib Oteracil potassium Otilonium bromide Oxaceprol Oxacillin Oxaliplatin Oxandrolone Oxantel Oxaprozin Oxatomide Oxazepam | Oxcarbazepine Oxedrine Oxiconazole Oxiracetam Oxolinic acid Oxomemazine Oxprenolol Oxybuprocaine Oxybutynin Oxycodone Oxycodone + Naloxone Oxyfedrine Oxymetazoline Oxymetholone Oxyphenbutazone Oxyphencyclimine Oxyphenonium Oxytetracycline Oxytocin Oxytocin + Ergometrine |