| Purpose | Patients | Evaluations | Perceived Effectiveness |
|---|---|---|---|
| Pain | 837 | 283 | |
| Breakthrough pain | 275 | 86 | |
| Fibromyalgia | 250 | 82 | |
| Back pain | 69 | 16 | |
| Pain in lower back | 38 | 10 |
Common side effects
| Side effect | Patients | Percentage |
|---|---|---|
| Constipation | 64 | |
| Drowsiness | 31 | |
| Nausea | 22 | |
| Dizziness | 13 | |
| Sleepiness | 12 | |
| Lightheadedness | 11 |
Side effect severity
| Severity | Evaluations | Percentage |
|---|---|---|
| Severe | 32 | |
| Moderate | 86 | |
| Mild | 153 | |
| None | 176 |