This study will be conducted to evaluate the effect of intraoperative systemic aminophylline infusion on pain intensity in patients undergoing ureteroscopic lithotripsy surgeries with ureteric stent placement at the end of the procedure.

Inclusion Criteria:

• Aged between 18 to 50 years
• American society of anesthesiology (ASA) physical status I - II
• Body mass index (BMI) less than 30.0 kg/m2
• Scheduled for ureteroscopic lithotripsy surgery with D-J ureteric stent placement at the end of procedure
• Under general anesthesia.

Exclusion Criteria:

1. Patients with central nervous system diseases, cardiovascular diseases, arrhythmias, cerebrovascular diseases, convulsions, renal impairment or hepatic dysfunction.
2. Pregnancy or lactation.
3. Patients with a history of allergy to aminophylline.
4. Coffee consumption (more than 2 cups/day)
5. Patients with opioid addiction or patients treated with B agonists, tranquilizers, or antidepressants.
6. Short procedures less than 30 minutes or procedures not requiring D-J stent placement.

The data will be available upon a reasonable request from the corresponding author

The data will be available 6 months after publication

The data will be available upon a reasonable request from the corresponding author