BACKGROUND: Postoperative pain after cardiac surgery has high incidence and is associated with worse morbidity. Pregabalin is a new antiepileptic drug used in patients with chronic pain and has been studied even more in postoperative. OBJECTIVE: Evaluate whether preemptive pregabalin use compared with placebo decreases pain perception in patients undergoing cardiac surgery in the first 24 hours and 2 months after hospital discharge; evaluate analgesic consumption in the immediate postoperative period; evaluate differences in blood gas parameters between groups; evaluate anesthetic recovery by QoR-40; assess incidence of serious adverse events (reintubation and mental confusion); incidence of delirium through the CAM-ICU questionnaire; assess adverse drug events (nausea, vomiting, pharmacodermia, allergic reactions). METHOD: Randomized, triple-blind, placebo-controlled clinical trial. EXPECTED RESULTS: Postoperative pain control with a drug that could cause fewer side effects, may lead to faster clinical improvement, fewer medications and fewer procedures, and lower healthcare costs with a decrease in intensive care unit (ICU) stay.

Inclusion Criteria:

• Patients who will undergo median sternotomy due to the need for cardiac surgery (valvular or myocardial revascularization);
• Patients between 18 and 70 years old;
• Patients able to swallow tablets and agree to participate in this clinical trial.

Exclusion Criteria:

• Patients with chronic renal failure with creatinine clearance less than or equal to 30 mL/min;
• Patients with known hypersensitivity to pregabalin;
• Hemodynamically unstable patients using vasoactive drugs the day before surgery;
• Unconscious and/or sedated patients, or without cognitive discernment to use the visual analog scale;
• Patients previously submitted to sternotomy; emergency surgery;
• Patients with neurological diseases; anticonvulsant drug users.