Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The safety of XTAMPZA ER was evaluated in a Phase 3, randomized-withdrawal, double-blind clinical trial involving 740 patients with moderate-to-severe chronic lower back pain. In the double-blind maintenance phase, 389 patients were randomized and 193 patients were assigned to the XTAMPZA ER treatment group.
The most common AEs (>5%) reported by patients in the Phase 3 clinical trial during the titration phase were: nausea (16.6%), headache (13.9%), constipation (13.0%), somnolence (8.8%), pruritus (7.4%), vomiting (6.4%), and dizziness (5.7%).
The most common adverse reactions (>5%) reported by patients in the Phase 3 clinical trial comparing XTAMPZA ER with placebo are shown in Table below:
Table 2: Common Adverse Reactions (>5%) | Titration | Maintenance |
|---|
| Adverse Reaction | XTAMPZA ER (n = 740) (%) | XTAMPZA ER (n = 193) (%) | Placebo (n = 196) (%) |
|---|
| Nausea | 16.6 | 10.9 | 4.6 |
| Headache | 13.9 | 6.2 | 11.7 |
| Constipation | 13.0 | 5.2 | 0.5 |
| Somnolence | 8.8 | <1 | <1 |
| Pruritus | 7.4 | 2.6 | 1.5 |
| Vomiting | 6.4 | 4.1 | 1.5 |
| Dizziness | 5.7 | 1.6 | 0 |
In the Phase 3 clinical trial, the following adverse reactions were reported in patients treated with XTAMPZA ER with incidences of 1% to 5%:
Eye disorders: vision blurred
Gastrointestinal disorders: abdominal pain, upper abdominal pain, diarrhea, gastroesophageal reflux disease
General disorders and administration site conditions: chills, drug withdrawal syndrome, fatigue, irritability, edema, pyrexia
Injury, poisoning and procedural complications: excoriation
Metabolism and nutrition disorders: decreased appetite, hyperglycemia
Musculoskeletal and connective tissue disorders: arthralgia, back pain, musculoskeletal pain, myalgia
Nervous system disorders: migraine, tremor
Psychiatric disorders: anxiety, insomnia, withdrawal syndrome
Respiratory, thoracic and mediastinal disorders: cough, oropharyngeal pain
Skin and subcutaneous tissue disorders: hyperhidrosis, rash
Vascular disorders: hot flush, hypertension
In the Phase 3 clinical trial, the following treatment-related adverse reactions were reported in patients treated with XTAMPZA ER with incidences of less than 1% of patients.
Investigations: increased gamma-glutamyl transferase, increased heart rate
Nervous system disorders: lethargy, memory impairment, poor-quality sleep
Psychiatric disorders: abnormal dreams, euphoric mood, restlessness
Respiratory, thoracic and mediastinal disorders: dyspnea
Skin and subcutaneous tissue disorders: night sweats