The effect of regular paracetamol use on the airways in asthma.

INTERVENTION: Subjects randomised to the treatment group will take paracetamol 1g (2 x 500mg tablets) four times per day for 14 days. CONDITION: Asthma PRIMARY OUTCOME: Airways resistance at 20Hz measured using an impulse oscillometry system (IOS) Airways resistance at 5Hz measured using an impulse oscillometry system (IOS) SECONDARY OUTCOME: Airways reactance at 5Hz (X5) using an impulse oscillometry system (IOS). Forced expiratory volume in one second (FEV1) using spirometry. Fraction of exhaled nitric oxide (FeNO) using an exhaled nitric oxide gas analyser. Markers of oxidative stress and prostaglandin metabolism present in the urine measured by enzyme immunoassay and mass spectrometry. Peripheral airways resistance (R5‐20Hz) using an impulse oscillometry system (IOS). INCLUSION CRITERIA: 1. A doctor’s diagnosis of asthma plus wheeze in the previous 12 months and asthma inhaler use in the previous 12 months 2.18 – 65 years old