| Reaction | |
|---|
| Abnormal dreams (66) | |
| Acute disseminated encephalomyelopathy (4) | |
| Ageusia (taste loss) / taste disorder (57) | |
| Aggression (includes anger) (45) | |
| Agitation (142) | |
| Akathisia (56) | |
| Allodynia (3) | |
| Altered mental status (8) | |
| Amnesia (82) | |
| Amyloid-related imaging abnormalities (ARIA) (1) | |
| Amyotrophic lateral sclerosis (2) | |
| Anorexia (302) | |
| Anorgasmia (12) | |
| Anosmia (smell loss) / smell disorder (see also hyposmia) (19) | |
| Antibiomania / antimicrobial-induced mania (see mania) | |
| Antiphospholipid antibody syndrome (7) | |
| Anxiety (270) | |
| Apathy (1) | |
| Aphasia (13) | |
| Arachnoiditis (6) | |
| Aseptic meningitis (37) | |
| Attention disturbances (3) | |
