Table 2.
Occurrence of Side Effects [Participants reporting (percentage)]a
| Side Effect | 4-Cl-KYN | Placebo |
|---|---|---|
| Headache | 6 (0.35) | 3 (0.16) |
| Chest pain | 1 (0.06) | 1 (0.05) |
| Stomach or abdominal discomfort | 1 (0.06) | 1 (0.05) |
| Diarrhea | 1 (0.06) | 1 (0.05) |
| Appetite decrease | 2 (0.12) | 1 (0.05) |
| Cramps | 1 (0.06) | 1 (0.05) |
| Eye irritation | 1 (0.06) | 1 (0.05) |
| Muscle/bone/joint pain | 5 (0.29) | 4 (0.21) |
| Tiredness/fatigue | 2 (0.12) | 3 (0.16) |
| Decreased motor activity | 2 (0.12) | 2 (0.11) |
| Difficulty falling asleep | 4 (0.24) | 2 (0.11) |
| Early morning awakening | 3 (0.18) | 6 (0.32) |
| Interrupted sleep | 4 (0.24) | 5 (0.26) |
| Drowsiness/sedation | 7 (0.41) | 2 (0.11) |
| Concentration difficulty | 2 (0.12) | 2 (0.11) |
| Memory problems | 3 (0.18) | 2 (0.11) |
| Anxiety | 2 (0.12) | 2 (0.11) |
| Irritability | 4 (0.24) | 4 (0.21) |
| Suicidal ideas | 1 (0.06) | 1 (0.05) |
| Not otherwise listed or unknown | 3 (0.18) | 1 (0.05) |
Abbreviation: 4-Cl-KYN, L-4-chlorokynurenine.
a Counts include all participants who reported moderate or severe symptoms after having mild or absent symptoms at baseline