Placebo-controlled double-blind trial of the analgesic effect and safety of clonidine in patients after major abdominal surgery

You likely can't join if

• • Sick sinus syndrome. • Second- or third-degree atrioventricular block. • Known hypersensitivity, intolerance or allergy towards clonidine or morphine. • Clinically relevant side effects or symptoms of allergy, judged by the investigator. • Pregnancy (positive urine HCG)/ lactating. • Participants with any clinical abnormalities that, in the opinion of the investigator, may increase the risk associated with trial participation or may interfere with the interpretation of the trial results • Participation in other clinical studies less than six month prior to inclusion. • Hypotension (persistent systolic blood pressure below 100 mmHg). • Bradycardia (< 50 beats/minute). • Known significant decreased kidney function, or an eGFR below 30 ml/min. • Use of a α-agonist drug. (Clonidine, Dexmedetomidine, Tizanidine). • Use of a α-adrenoceptor blocking drug. (Phentolamine, Tolazoline, Phenoxybenzamine, Prazosin, Terazosin, Doxazosin, Alfuzosin, Bunazosin, Tamsulosin, Silodosin, Yohimbine, Idazoxan, Ergot alkaloids).