| Antiandrogens, steroidal | Not Available | 0 | 0 | Details |
| Antianemia Drugs | Not Available | 4 | 31 | Details |
| Antianemic Preparations | Not Available | 31 | 180 | Details |
| Antianginal Agents | Not Available | 16 | 61 | Details |
| Antianginals, sydnone derivatives | Not Available | 0 | 0 | Details |
| Antiarrhythmic agents | Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the... more | 182 | 1239 | Details |
| Antiarrhythmics, Class I | Not Available | 19 | 135 | Details |
| Antiarrhythmics, Class Ia | Reduce phase 0 slope and peak of the cardiac action potential. Moderate reduction in p... more | 9 | 68 | Details |
| Antiarrhythmics, Class Ib | Small reduction in phase 0 slope; reduce APD (atrial premature depolarization); decreas... more | 4 | 39 | Details |
| Antiarrhythmics, Class Ic | Pronounced reduction in phase 0 slope; no effect on APD (atrial premature depolarizatio... more | 8 | 31 | Details |
| Antiarrhythmics, Class III | Delay repolarization (phase 3) and thereby increase action potential duration and effec... more | 9 | 93 | Details |
| Antiarrhythmics, Class V | Other antiarrhythmics with various mechanisms which do not fit into the other classes o... more | 1 | 21 | Details |
| Antiarthritic substances | Antiarthritic substances acting similarly to clobuzarit and lobenzarit. The mechanism o... more | 0 | 0 | Details |
| Antibacterial monoclonal antibodies | Not Available | 4 | 3 | Details |
| Antibacterials for Systemic Use | Not Available | 236 | 1188 | Details |
| Antibacterials, quinoline dioxide derivatives | Not Available | 0 | 0 | Details |
| Antibiotics for Pneumocystis Pneumonia | Antibiotic agents that may be used for the treatment of, or prophylaxis against, pneumo... more | 8 | 80 | Details |
| Antibiotics for Topical Use | Not Available | 16 | 110 | Details |
| Antibiotics, 6-aminopenicillanic acid derivatives | Not Available | 0 | 0 | Details |
| Antibiotics, Antineoplastic | Chemical substances, produced by microorganisms, inhibiting or preventing the prolifera... more | 45 | 223 | Details |
| Antibiotics, Antitubercular | Substances obtained from various species of microorganisms that are, alone or in combin... more | 10 | 92 | Details |
| Antibiotics, cefalosporanic acid derivatives | Not Available | 0 | 0 | Details |
| Antibiotics, oxacefalosporanic acid derivatives | Not Available | 0 | 0 | Details |
| Antibiotics, polyene derivatives | Not Available | 0 | 0 | Details |
| Antibodies | Immunoglobulin molecules having a specific amino acid sequence by virtue of which they ... more | 543 | 758 | Details |