Effects of cimetidine in control of post operative pain

Introduction: Pain is the most common complaint of patients and therefore its treatment is the mostancient problem of human being. Since opioids have many side effects, morphine (MOR) areadministrated limitedly. Recent studies have shown that cimetidine (CIM) induces analgesia in animalsand humans. This study was designed to evaluate the effect of CIM in control of post operative pain.Materials and Methods: This study was a double-blind clinical trial. Following filling a consentform, one hundred and twenty patients (male & female) were randomly divided to four groups. Thefirst three groups, as CIM groups, were received different doses of CIM (3mg /kg, 6mg /kg and 8mg/kg) and the last group given MOR (o.1 mg/kg). The drugs were injected (IV) in peak of pain duringpost operation period. Numeric rating pain scale (RPS) method was used for pain scaling. Pain wasmeasured in 30 min, 60 min and 120 min after injection the drug and compared with pain score beforeinjection of the drug.Results: Pain intensity was not significantly different prior to injection, 30 , 60 min and 120 minafter drug injections in all four groups (MOR and CIM groups), but it was significantly lower whencompared with pain score before injection of drug (P< 0.05). In addition, there were no significantdifferences in duration of analgesia among four groups.Conclusions: The results of this study indicated that the analgesic effects (time and quality) of CIM(each three doses) are compatible with that those induced by MOR. Therefore, It seems that CIM is asafe drug in control of post operative pain.