Adding Amantadine to Pregabalin on Occurrence of Post-thoracotomy Pain Syndrome

Two hours preoperative, patient will receive two capsules, one of them is Amantadine (Amantadine Hydrochloride) 100 mg and the other is Pregabalin (Lyrica) 75 mg and continued on both of them twice daily for 5 days postoperative.

Two hours preoperative, the patient will receive two capsules, one of them is pregabalin 75 mg, and the other is a placebo capsule similar to the amantadine capsule and continued on both of them twice daily for 5 days postoperative.