Barbiturates gastrointestinal effects

SAFETY PROFILE Poison by intravenous and implant routes. Human systemic effects by intravenous route blood pressure lowering, gastrointestinal effects, and allergic dermatitis. An FDA proprietar drug. Caution Excessive use may lead to addiction or habituation. Allergenic effects by intravenous route. When heated to decomposition it emits toxic fumes of Na20 and NO.. See also BARBITURATES. 

There appears to be little difference between benzodiazepines and kava extract in anxiolytic activity. However, kava extracts seem to have fewer side effects. Two studies with more than 3000 patients each found unwanted events in about 2% of patients during treatment with kava extract. The more frequently reported side effects were gastrointestinal complaints, allergic skin reactions, headache, and photosensitivity (Pittler and Ernst, 2000). There have been isolated reports of hepatotoxicity and acute liver failure (Escher et ah, 2001). Kava may potentiate the sedative effects of other medications including barbiturates and benzodiazepines. Kava can also cause behavioral disinhibition in a minority of individuals, including children. The most common problem, which is usually associated with persistent and excessive usage, is a scaly skin rash called kava dermopathy, which is reversible. 

Koizumi, K. and Kidera, Y. 1977. Effect of- andfS-cyclodextrin on gastrointestinal absorption of barbituric acid derivativesYakugaku Zasshi, 97 705-711. 

Studies have shown that gastrointestinal mucus presents a physical barrier to the diffusion of small molecules such as urea, benzoic acid, antipyrine, 1-phenylalanine and warfarin as well as to large protein molecules. Similarly, the passive absorption of testosterone was shown to be doubled upon ridding the intestinal epithelial cells of the overlying mucus layer. However, the situation regarding the effect of mucus on oral bioavailability is a complex one for example, it has been shown that drag binding to the mucosal surface is essential to the absorption of barbituric acid derivatives from the rat small intestine. 

All the barbiturates possess the properties of CNS depressants. Thus, in moderate doses they produce a drunken euphoric state. Similar to alcohol, barbiturates may produce a loss of motor coordination, a staggering gait, and slurred speech. Loss of emotional control and behavioral disinhibition arc also characteristic cfTccts. Sedation and sleep are produced by increased doses, and higher doses produce surgical anesthesia. Physiological effects include respiratory depression, which is responsible for most of the overdose deaths associated with barbiturates. In addition some depression of heart rate, blood pressure, and gastrointestinal activity is noted at higher doses. 

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