Table 4.
Side Effects from Pre-exposure Prophylaxis Cohort
| Hydroxychloroquine 2x Per Week, No. (%) | Hydroxychloroquine 1x Per Week, No. (%) | Placebo | P Value | |
|---|---|---|---|---|
| No. randomized | 495 | 494 | 494 | |
| No. with completed surveys | 463 | 473 | 469 | |
| Any side effect | 168 (36.4) | 148 (31.3) | 100 (21.4) | <.001 |
| Side effects | ||||
| Nausea or upset stomach | 90 (19.4) | 83 (17.5) | 57 (12.2) | .03 |
| Diarrhea, abdominal pain, or vomiting | 79 (17.1) | 61 (12.9) | 35 (7.5) | <.001 |
| Palpitations | 6 (1.3) | 4 (0.8) | 8 (1.7) | .51 |
| Irritability, dizziness, vertigo | 24 (5.2) | 27 (5.7) | 22 (4.7) | .80 |
| Tinnitus | 7 (1.5) | 10 (2.1) | 5 (1.1) | .44 |
| Fatigue | 5 (1.1) | 1 (0.2) | 1 (0.2) | .10 |
| Visual changes | 4 (0.9) | 7 (1.5) | 3 (0.6) | .41 |
| Skin reaction | 23 (5.0) | 13 (2.7) | 11 (2.3) | .07 |
| Allergic reaction | 4 (0.9) | 2 (0.4) | 3 (0.6) | .70 |
| Sleep disturbance | 7 (1.5) | 10 (2.1) | 7 (1.5) | .71 |
| Myalgia | 2 (0.4) | 7 (1.5) | 2 (0.4) | .11 |
| Arrhythmias | 1 (0.2) | 0 (0.0) | 1 (0.2) | – |
| Other, <1% each | 11 (2.3) | 11 (2.3) | 8 (1.7) | – |
P values were calculated using the chi-square test. The percentages of side effects are from participants who completed surveys since starting medication. The median number of side effects is among those reporting side effects. Of arrhythmias in the hydroxychloroquine group, this was a new supraventricular tachycardia resulting in syncope and hospitalization. In the placebo group, new atrial fibrillation occurred in 1 person, resulting in 2 hospitalizations.