Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic administration of caffeine to mice (1 mg/ml in drinking water X 14 d) led to a downward shift in the dose-response curve for the locomotor effects of caffeine. Caffeine was also less effective as an antagonist against (-)-(N6-phenylisopropyl)-adenosine (PIA)-induced analgesia in the tail flick assay in these animals. The dose-response curves of PIA for both analgesia and locomotor depression were shifted to the left in animals chronically administered caffeine. In mice chronically administered PIA (1 mg/kg/d X 14 d), the dose-response curves of PIA for both analgesia and locomotor depression were shifted to the right. The dose-response curve for the locomotor effects of caffeine was shifted to the left, and caffeine exhibited greater antagonist activity against the analgesic action of PIA in these animals. There was no change in the Kd or Bmax values of either 3H-PIA or 3H-diethylphenylxanthine (DPX, a potent adenosine receptor antagonist) in mice chronically administered PIA. The Bmax values for both 3H-PIA and 3H-DPX were significantly increased, while the Kd values were not changed in mice chronically administered caffeine. There was no detectable change in the brain levels of either PIA or caffeine in animals chronically treated with either drug. The results demonstrate that chronic administration of caffeine increases the sensitivity of mice to the actions of PIA and vice versa, providing supportive evidence for the interaction of these drugs at the same receptor, which is probably an adenosine receptor.
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PMID:Cross-tolerance studies between caffeine and (-)-N6-(phenylisopropyl)-adenosine (PIA) in mice. 300 86

Morphine-induced analgesia, and the development of morphine-induced tolerance and dependence was determined in mice which had drunk caffeinated water (1 mg/ml) for 14 days or in mice which had received (-)-N6-(phenylisopropyl)-adenosine (PIA) 1 mg/kg i.p. for 14 days. Analgesia was assessed by the tail flick assay. The development of dependence was assessed by determining the ED50 of naloxone to precipitate withdrawal jumping (3 h after 100 mg/kg morphine pretreatment or 72 h after s.c. implantation of a morphine 75 mg pellet) and by determining the extent of naloxone-precipitated hypothermia in morphine-implanted animals. In mice chronically administered caffeine, the ED50 for morphine-induced analgesia was significantly decreased while the naloxone ED50 for withdrawal jumping increased by 2-fold after both types of morphine pretreatment. In control animals (tap water for 14 days), doses of 1 and 10 mg/kg of naloxone caused significant hypothermia in morphine-implanted animals. Doses of naloxone up to 100 mg/kg did not cause significant hypothermia in morphine-implanted animals which had received chronic caffeine. The development of tolerance was determined by computing the morphine potency ratio for the tail flick assay (tolerant ED50/control ED50). In mice chronically administered caffeine, the potency ratio was decreased significantly in morphine-implanted animals when compared to control. Morphine-induced analgesia, tolerance and dependence was not changed significantly in animals chronically administered PIA. Neither the distribution of morphine to the brain nor the opioid receptor binding parameters for [3H]etorphine and [3H]naltrexone were altered in mice chronically administered caffeine or PIA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effect of chronic administration of caffeine on morphine-induced analgesia, tolerance and dependence in mice. 300

Treatment of mice with either a 75-mg morphine pellet (72 h) s.c. or 100 mg/kg of morphine s.c. (3.5 h) did not alter the ED50 of (-)-N6-(phenylisopropyl)adenosine (PIA) in the tail-flick assay. Under the same treatment conditions, caffeine became a more potent antagonist of PIA-induced analgesia, and the dose-response curve for the locomotor effects of caffeine was shifted to the left. There was no change from control in the distribution of caffeine to the brain in mice pretreated with morphine. Brain levels of PIA were decreased significantly at the two highest doses used to elicit analgesia in morphine-implanted mice when compared to control. Adenosine receptor binding assays, utilizing [3H]PIA and [3H]diethylphenylxanthine as agonist and antagonist ligands, respectively, revealed significant increases in the Bmax values for both ligands without changes in Kd in morphine-implanted mice when compared to control. These data suggest that there is an increase in sensitivity to drugs which interact with adenosine receptors in morphine-tolerant and -dependent mice.
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PMID:Changes in adenosine receptor sensitivity in morphine-tolerant and -dependent mice. 300 48

The analgesic efficacy of a single 50-mg preoperative dose of flurbiprofen was compared with ACC-30 (aspirin 375 mg, codeine 30 mg, caffeine 30 mg) and a placebo. Forty patients scheduled for the surgical removal of impacted maxillary third molars were enrolled in a double-blind, randomized study. Using a within-subject design we compared the analgesic efficacy of (1) preoperative flurbiprofen 50 mg with placebo in 20 patients, and (2) preoperative ACC-30 with placebo in 20 other patients. Using a between-group design, we then compared the analgesic efficacy of (3) each drug given preoperatively and postoperatively, and (4) each drug given postoperatively only. Patients rated 2 pain dimensions, intensity and unpleasantness, hourly for 8 hours after the presurgical dose. The results of this study indicate that better analgesia was obtained when flurbiprofen was given preoperatively compared to only after surgery. Conversely, preoperative administration of ACC-30 did not demonstrate any significant influence on postsurgical analgesia. When comparing the 2 drugs, flurbiprofen proved to be superior in providing pain relief only when it was given prior to surgery. There was no difference between them when given only after surgery. Side effects were moderate and not significantly different between patients receiving flurbiprofen and those receiving ACC-30.
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PMID:Preoperative flurbiprofen in oral surgery: a method of choice in controlling postoperative pain. 305 Sep 5

The influence of various doses of caffeine and theophylline on analgesic effect of morphine was tested in mice and rats in the hot plate and tail immersion tests. Caffeine in rats potentiated the morphine analgesia in both tests in a dose-dependent manner. In mice the caffeine-morphine interaction was biphasic: lower caffeine doses (10 and 25 mg/kg) inhibited, while higher (75 and 100 mg/kg) potentiated the analgesic effects of morphine. Theophylline interacted with morphine in a manner similar to that of caffeine.
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PMID:The effect of methylxanthines on morphine analgesia in mice and rats. 324 63

The efficacy of an aspirin-caffeine-codeine-butalbital combination was compared to an acetaminophen-codeine combination and placebo in outpatients who had moderate or severe pain after the surgical removal of impacted third molars. Using a self-rating record, patients rated their pain, relief, anxiety and relaxation hourly for up to 6 hours after medicating. Each active medication was significantly superior to placebo for measures of analgesia and relaxation. Although the butalbital-containing combination provided consistently greater analgesia, the differences between active medications were not statistically significant. The acetaminophen-codeine combination significantly reduced anxiety; however, the butalbital containing combination did not. The results of this study suggest that female patients may have greater efficacy than male patients. All adverse effects were transitory and consistent with the known pharmacologic profiles of the study medications or the backup analgesic.
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PMID:Analgesic effect of an aspirin-codeine-butalbital-caffeine combination and an acetaminophen-codeine combination in postoperative oral surgery pain. 354 Aug 75

High doses of caffeine-containing as well as decaffeinated instant coffee neither inhibited morphine-induced analgesia in mice nor the morphine-induced fall of blood pressure, heart rate and respiratory rate in rats. On the contrary, caffeine-containing coffee even enhanced the analgesic effects of morphine in mice. Coffee thus does not exhibit opiate-antagonizing activity in the whole organism in vivo. The very weak morphine-antagonistic efficacy of coffee powder in the myenteric plexus-longitudinal muscle preparation from the guinea pig ileum is of no practical importance.
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PMID:Failure of coffee to inhibit the pharmacodynamic activity of morphine in vivo. 375 83

The absorption rate and the bioavailability of two commercially available paracetamol tablets were investigated in a panel of seven volunteers; one of these tablets contained a combination of 50 mg caffeine and paracetamol. Considering the urinary excretion data, it is concluded that the tablets release their contents completely; the absolute bioavailability, however, calculated from plasma concentrations, is lower than 100%, indicating a first-pass effect. A marked interindividual variation in first-pass effect was noticed. No general influence of caffeine on the extent of absorption of paracetamol could be established; there is, however, a slightly positive influence of caffeine on the absorption rate of paracetamol in six out of seven volunteers. It was concluded that this positive influence on absorption rate is not responsible for the established enhancement of paracetamol analgesia by caffeine.
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PMID:Bioavailability of paracetamol after oral administration to healthy volunteers. Influence of caffeine on rate and extent of absorption. 376 69

A two-phase, double-blind study was performed to assess the efficacy of various drugs in the relief of postoperative pain. Oral analgesia with two compounds (paracetamol 320 mg, caffeine 32 mg, codeine phosphate 8 mg and meprobamate 150 mg (Stopayne; Rio Ethicals) and dipyrone 500 mg, pitofenone hydrochloride 5 mg and fenpiverinium bromide 0,1 mg (Baralgan HS; Albert)) was found to produce satisfactory pain relief, and it is suggested that these oral compounds may be used from 12 hours postoperatively in uncomplicated cases. Parenteral administration of either pethidine 100 mg or dipyrone 2500 mg was found to be an ineffective form of pain relief, and it is suggested that the use of these drugs should be reviewed. In both phases of the study side-effects were infrequent and mild, and smoking did not have an influence on the results.
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PMID:Analgesics for pain relief after gynaecological surgery. A two-phase study. 388 41

Significant potentiation of morphine (5 mg kg-1 s.c. or 1 mg kg-1 i.v.) analgesia (tail-withdrawal reflex at 55 degrees C) was observed in caffeine-treated (100 mg kg-1 i.p.) rats as compared to the control group and lower doses of caffeine (2mg kg-1 i.p.) did not show this effect. Potentiated analgesia was reversed by naloxone. Pharmacokinetic or dispositional factors appear to be involved in part in this potentiation.
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PMID:Potentiation of morphine analgesia by caffeine. 400 85


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