Reversal of an antihistamine-induced coma with flumazenil.

Flumazenil is a competitive antagonist with specific action at the central benzodiazepine receptor. It is used when benzodiazepine intoxication is suspected. Its use has also been reported in cannabis intoxication, chloral hydrate overdose, hepatic encephalopathy, and alcohol intoxication. We report the case of a 7-month-old male infant with a depressed level of consciousness after intentional intoxication of antihistamines, whose mental status fully recovered after administration of flumazenil. To our knowledge, this is the first case in children where flumazenil has been reported to reverse antihistamine-induced coma.

Quantitation of N,N-dimethyltryptamine and harmala alkaloids in human plasma after oral dosing with ayahuasca.

Harmine, harmaline, tetrahydroharmine (THH), and N,N-dimethyltryptamine (DMT) were quantitated in plasma from 15 healthy male volunteers after the ingestion of ayahuasca, a beverage that has been used for religious purposes in Brazil since pre-Columbian times. A growing awareness of the interest in this ancient shamanistic practice in modern urban cultures and the widespread popular dissemination of the inebriant effects and type and sources of the plant admixtures used to prepare the beverage have provided additional impetus for this study. The three harmala alkaloids were quantitated from protein-precipitated plasma by high-performance liquid chromatography using fluorescence detection. Recovery from blank human plasma was quantitative, and the limit of quantitation (LOQ) was below 2 ng/mL of plasma for each of the harmala alkaloids. Standard concentrations ranged from 10 to 250 ng/mL for harmine and THH and from 1.0 to 25.0 ng/mL for harmaline, respectively. Linearity was observed for harmine, harmaline, and THH within these respective ranges. The highest concentrations of harmala alkaloids in human plasma were found to be 222.3 ng/mL for harmine, 134.5 ng/mL for THH, and 9.4 ng/mL for harmaline. DMT was quantitated by gas chromatography using nitrogen-phosphorus detection after liquid-liquid extraction with diphenhydramine as an internal standard. DMT recovery was quantitative, and the limit of detection and LOQ were 0.5 and 5 ng/mL, respectively. Linearity for DMT was observed from 5 to 1000 ng/mL. The one-step extraction method for DMT and the protein precipitation method for the three harmala alkaloids afford rapid, sensitive, and quantitative analyses of these alkaloids with minimal analyte loss. The analytical methods also may be applicable to other matrices, including whole blood and urine samples and homogenized tissue specimens. These are the first reported observations of DMT and harmala alkaloids in plasma after ritual ingestion of ayahuasca.

[Experimental study of the antiedema activity of antihistamine preparations compared to the dynamics of their concentration in the blood serum]. / Eksperimental'noe issledovanie protivootechnoi aktivnosti nekotorykh antigistaminnykh preparatov v sopostavlenii s dinamikoi ikh kontsentratsii v syvorotke krovi.

The time-course of the antiexudative effect of the antihistaminic drugs diphenhydramine, phencarol and suprastin was studied in experimental dextran edema of the rat hind limb after intragastric administration of the drugs in a dose of 50 mg/kg. The data obtained were correlated to the time-course of the blood serum drug concentration measured by high pressure liquid chromatography. The relationship between the pharmacological action of the drugs and the mean maintenance dose was depicted by means of computer. It has been shown that the antiexudative activity of diphenhydramine and phencarol is approximately identical, whereas the efficacy of suprastin is several times less.