The purpose of this study was to investigate the differences in subjective acute effects of alcohol and naltrexone among those who prefer spicy food to varying degrees. Acute biphasic alcohol effects scale (BAES), visual analogue scale for craving (VAS-C), blood alcohol concentration (BAC) and food preference scale were measured in 26 men. Repeated measures ANOVA (2 preference groupsx4 time blocks) on the stimulative subscale of BAES revealed a significant group by block interaction in naltrexone condition (N+) (P<0.001), but not in non-naltrexone condition (N-). Furthermore, repeated measures ANOVA (2 drug groupsx4 time blocks) on the stimulative subscale of BAES revealed a significant group by block interaction in strong preference for spicy food (SP) (P<0.001), but not in lesser preference for spicy food (LP). The paired t-test revealed that significant suppression of the stimulative subscale of BAES was observed at 15 min (P<0.001) and 30 min (P<0.001) after drinking when N+ compared with N- in SP. For those who prefer spicy food, the stimulative effect of acute alcohol administration was suppressed by naltrexone. This result suggests that the effect of naltrexone may vary according to spicy food preference.
Adult ; Alcohol Drinking/*adverse effects ; Alcoholism/*drug therapy ; Capsaicin/pharmacology ; Food Preferences/*drug effects ; Humans ; Male ; Naltrexone/adverse effects/*therapeutic use ; Narcotic Antagonists/adverse effects/*therapeutic use ; Questionnaires ; Sensory System Agents/pharmacology ; Young Adult

BACKGROUNDEarly studies showed that naloxone infusion decreases the incidence of morphine-related side effects from intravenous patient-controlled analgesia. This study aimed to determine whether naloxone preserved analgesia while minimizing side effects caused by intravenous tramadol administration.

METHODSEighty patients undergoing general anesthesia for cervical vertebrae surgery were randomly divided into four groups. All patients received 1 mg/kg tramadol 30 minutes before the end of surgery, followed by a continuous infusion with 0.3 mg x kg(-1) x h(-1) tramadol with no naloxone (group I, n = 20), 0.05 microg x kg(-1) x h(-1) naloxone (group II, n = 20), 0.1 microg x kg(-1) x h(-1) naloxone (group III, n = 20) and 0.2 microg x kg(-1) x h(-1) naloxone (group IV, n = 20). Visual analog scales (VAS) for pain during rest and cough, nausea five-point scale (NFPS) for nausea and vomiting, and ramsay sedation score (RSS) for sedation were assessed at 2, 6, 12, 24 and 48 hours postoperatively. Analgesia and side effects were evaluated by blinded observers.

RESULTSSeventy-eight patients were included in this study. The intravenous tramadol administration provided the satisfied analgesia. There was no significant difference in either resting or coughing VAS scores among naloxone groups and control group. Compared with control group, sedation was less in groups II, III, and IV at 6, 12, and 24 hours (P < 0.05); nausea was less in groups II, III and IV than group I at 2, 6, 12, 24 and 48 hours postoperatively (P < 0.05). The incidence of vomiting in the control group was 35% vs. 10% for the highest dose naloxone group (group IV) (P < 0.01).

CONCLUSIONA small-dose naloxone infusion could reduce tramadol induced side effects without reversing its analgesic effects.

Analgesia, Patient-Controlled ; methods ; Analgesics, Opioid ; administration & dosage ; adverse effects ; therapeutic use ; Anesthesia, General ; methods ; Cervical Vertebrae ; surgery ; Female ; Humans ; Infusions, Intravenous ; Male ; Middle Aged ; Naloxone ; administration & dosage ; adverse effects ; therapeutic use ; Narcotic Antagonists ; administration & dosage ; adverse effects ; therapeutic use ; Nausea ; chemically induced ; Tramadol ; administration & dosage ; adverse effects ; therapeutic use