Drug Interactions Directory

2,618 drugs with documented interactions.

2,618Drugs
67,117Interactions
53,805Serious (major+)
PharmacistReviewed
1Look up a drugSearch by generic or brand name, or browse A-Z.
2Scan the severityInteractions are grouped and color-coded by how much they matter.
3Read the write-upPlain-English and clinical explanations, with cited evidence.
Popular: Buprenorphine 633 Hydroxychloroquine 631 Ketoconazole Topical 546 Cyclosporine Injection 545 Cyclosporine Ophthalmic 545 Sertraline 532 Amitriptyline 525 Fentanyl Transdermal Patch 493

Sources: FDA prescribing information (Structured Product Labeling), the published literature cited in each entry, DDInter 2.0 (a major open-access drug-interaction database), and legacy DrugBank interaction data distributed by the NIH's RxNav service (decommissioned in 2024) — analyzed and reviewed by our pharmacist team. How we build this library →

N
Nutmeg 1
O
Oat Bran 4 Obeticholic Acid 25 Obinutuzumab Injection 15 Ocrelizumab Injection 43 Octreotide 380 Octreotide Acetate 19 Octreotide Injection 342 Odevixibat 4 Ofatumumab Injection (Multiple Sclerosis) 15 Ofloxacin 386 Ofloxacin Ophthalmic 337 Ofloxacin Otic 337 Olanzapine 101 Olaparib 141 Olaratumab Injection 15 Oleander 1 Oleandomycin 1 Oliceridine 57 Olmesartan 51 Olmesartan Medoxomil 6 Olodaterol 112 Olodaterol Oral Inhalation 316 Olopatadine 7 Olopatadine Nasal Spray 7 Olsalazine 24 Olsalazine Sodium 7 Olutasidenib 85 Omacetaxine Injection 15 Omadacycline 60 Omadacycline Injection 51 Omaveloxolone 121 Ombitasvir 15 Omega-3-Acid Ethyl Esters 19 Omega-3-Carboxylic Acids 16 Omeprazole 142 Ondansetron 84 Opicapone 13 Opipramol 48 Opium 29 Opium Alkaloids 29 Orforglipron 16 Oritavancin 11 Orlistat 144 Ornidazole 5 Orphenadrine 26 Oseltamivir 5 Osilodrostat 70 Osimertinib 73 Ospemifene 43 Oteseconazole 5 Oxacillin 18 Oxaliplatin 65 Oxaliplatin Injection 232 Oxandrolone 20 Oxaprozin 91 Oxatomide 1 Oxazepam 22 Oxcarbazepine 39 Oxitropium Bromide 10 Oxprenolol 59 Oxybutynin 21 Oxycodone 62 Oxymetazoline 8 Oxymetazoline Hydrochloride 1 Oxymetholone 1 Oxymorphone 45 Oxyphenbutazone 91 Oxypurinol 12 Oxytetracycline 22 Oxytocin 1 Oxytocin Injection 2 Ozanimod 86
P
Paclitaxel 41 Paclitaxel Protein-Bound 28 Pacritinib 101 Pafolacianine 1 Palbociclib 47 Palifermin 2 Paliperidone 84 Palonosetron 17 Palonosetron Injection 113 Palovarotene 16 Paltusotine 33 Pancreatin 2 Pancrelipase 3 Pancuronium 24 Panitumumab Injection 15 Panobinostat 63 Pantoprazole 29 Papaveretum 29 Papaverine 33 Papaya 5 Paraldehyde 1 Paramethasone 7 Parathyroid Hormone 2 Parathyroid Hormone Injection 2 Parecoxib 94 Paregoric 29 Pargyline 5 Paricalcitol 16 Paritaprevir 73 Parnaparin 49 Paromomycin 11 Paroxetine 141 Pasireotide 64 Pasireotide Diaspartate 19 Passionflower 4 Patiromer 10 Pau D'arco 5 Pazopanib 91 Pazufloxacin 13 Pectin 5 Pefloxacin 13 Pegademase Bovine 1 Pegaspargase Injection 15 Peginterferon Alfa-2A 5 Peginterferon Alfa-2A Injection 31 Peginterferon Alfa-2B 5 Pegloticase 2