The goal of this RCT is to compare the effectiveness of aminophylline and furosemide combination vs furosemide alone in producing effective diuresis in critically ill adults in ICU. ICU patients with the need of improved diuresis will be recruited and given either infusion of aminophylline and furosemide combination or furosemide alone, and their hourly urine output will be monitored to compare their effectiveness.

Inclusion Criteria:

• Patients aged 18 years old and above who are admitted to the ICU of UMMC during the study period
• Oliguric patients, with the need for improved diuresis at clinician discretion - defined as urine output <0.5ml/kg/hour

Exclusion Criteria:

• Patient refusal for participation of study
• Patients with known hypersensitivity reaction to aminophylline or furosemide
• Patients with history of tachyarrhythmias, seizures, aspartate aminotransferase or alanine aminotransferase > 3 times normal, or hypothyroidism.

Patient with existing peptic ulcer disease or coagulopathy with INR > 1.5

Recruited patient randomised into intervention vs control group by non clinical personnel, trial drugs dilution by research assistant, drug administered to patient by staff nurses, data collection by independent group