Several clinical studies and case reports suggested that aminophylline antagonizes the effects of diazepam , barbiturates , sevoflurane ,morphineand propofol.However, the available results from uncontrolled clinical settings make it difficult to quantify the specific effects of aminophylline on hypnotics and anesthetics

Aminophylline, a theophylline derivative, exerts multiple pharmacological effects, either through phosphodiesterase inhibition (i.e., a potent bronchodilating action, which is often used for the treatment of bronchial asthma) or via adenosine receptor blockade .It is generally considered that the majority of actions ascribed to therapeutic doses of xanthines (caffeine and theophylline) are due to their action as adenosine receptor antagonists.

To the best of the investigator's knowledge this hypothesis was not reported in patients scheduled for major pelvi-abdominal surgeries under general anesthesia , and aminophylline was not given as premedication to test this hypothesis as it was previously administrated after the end of surgery ,also it was recommended by previous clinical studies to evaluate the effective dose of aminophylline that affect the extubation and recovery time.

Inclusion Criteria:

• Patients age: 20-60 years
• Males and females patients
• American Society Of Anesthesiology (ASA) physical status I- II .

Exclusion Criteria:

• Patient refusal to participate in this study
• Patient with known sensitivity to aminophylline
• Patients with history of cardiac failure
• Patients with renal or hepatic dysfunction and in chronic alcoholism since clearance of aminophylline is decreased.
• Patients with peptic ulcer, hyperthyroidism, glaucoma,as these conditions may be exacerbated.
• Patients with opioid addiction
• Current treatment with B agonists, anticholinergic agents, tranquilizers, anticonvulsants ,or antidepressants.
• Pregnancy.
• Habitual coffee consumption exceeding 2 cups per day.