| AUROVERTIN B | | | 0 |
| Atopaxar | 751475-53-3 | | 0 |
| Atpenin A5 | 119509-24-9 | | 0 |
| Atracurium | 64228-79-1 | Central Nervous System Agents | 0 |
| Atrasentan | 173937-91-2 | Anticancer drugs | 0 |
| Atrazine | 1912-24-9 | Dermatological Agents | 0 |
| Atreleuton | 154355-76-7 | Enzyme Replacements/modifiers | 0 |
| Attapulgite | 12174-11-7 | | 0 |
| Auriclosene | 846056-87-9 | | 0 |
| Aurodox | 12704-90-4 | Anti-infective Agents | 0 |
| Aurothioglucose | 12192-57-3 | | 0 |
| Aurotioprol | 27279-43-2 | Antidotes, Deterrents, and Toxicologic Agents | 0 |
| Autogene cevumeran | 2365453-34-3 | Anticancer drugs | 0 |
| Avacincaptad pegol | 1613641-69-2 | | 0 |
| Avadomide | 1015474-32-4 | | 0 |
| Avagacestat | 1146699-66-2 | Enzyme Replacements/modifiers | 0 |
| Avalglucosidase alfa | 1802558-87-7 | Cardiac stimulants | 0 |
| Avalotcagene ontaparvovec | 2227000-30-6 | | 0 |
| Avasimibe | 166518-60-1 | Enzyme Replacements/modifiers | 0 |
| Avasopasem manganese | 435327-40-5 | Antioxidants | 0 |
| Avdoralimab | 2226393-85-5 | Anti-infective Agents | 0 |
| Avermectin | 73989-17-0 | | 0 |
| Avexitide | 133514-43-9 | Other substances | 0 |
| Avidin | 110539-97-4 | Enzyme Replacements/modifiers | 0 |
| Avilamycin | 11051-71-1 | Anti-infective Agents | 0 |
| Aviptadil | 40077-57-4 | Hormonal Agents | 0 |
| Aviscumine | 223577-45-5 | Other substances | 0 |
| Avoralstat | 918407-35-9 | Dental and Oral Agents | 0 |
| Avotaciclib | 1983983-41-0 | Anticancer drugs | 0 |
| Avotermin | 182212-66-4 | Other substances | 0 |
| Avutometinib | 946128-88-7 | Other substances | 0 |
| Axatilimab | 2155851-88-8 | Other substances | 0 |
| Axelopran | 949904-48-7 | Other substances | 0 |
| Axomadol | 187219-99-4 | | 0 |
| Azanidazole | 62973-76-6 | Antiparasitics | 0 |
| Azapentacene | 3863-80-7 | | 0 |
| Azapetine | 146-36-1 | Antihypertensive agents | 0 |
| Azapropazone | 13539-59-8 | | 0 |
| Azasetron | 123040-69-7 | Antiemetics | 0 |
| Azatadine | 3964-81-6 | | 0 |