Short-lived Metabolites

Active against anaerobic organisms and under such conditions it is reduced to a short-lived metabolite that damages DNA. Oral doses are highly bioavailable but 40-80% of the parent compound can be excreted. 

Eicosanoids in the form of prostaglandins, prostacyclins, thromboxanes, and leukotrienes are short-lived metabolites of fatty acids which affect a variety of tissues in the body. 

When heroin is metabolized in the body, there is a short-lived metabolite called 6-monoacetylmorphine (6-MAM), created by removal of one of the acetyl groups. It is believed that 6-MAM may be the source of the intense rush of euphoria associated with heroin taking, before it is ultimately converted to morphine. 6-MAM can only arise from heroin, but it persists in the body for less than a day, so it can only be detected within 24 h of that person taking heroin. 

Development of analytical procedures to detect minute and short-lived reactive metabolites (Miyamoto 1988)... 

M. Haaparanta, T. Gronroos, O. Eskola, J. Bergman, O. Solin, Planar chromatographic analysis and quantification of short-lived radioactive metabolites from microdialysis fractions, J. Chromatogr. A 1108 (2006) 136-139. 

BZDs that undergo a high first-pass effect before reaching the systemic circulation (e.g., brotizolam, clotiazepam, midazolam, and triazolam) may have short-lived but active metabolites. 

As a result of their high reactivity, reactive metabolites are often considered to be short-lived. This is not always true, however, because reactive intermediates can be transported from one tissue to another, where they may exert their deleterious effects. Thus reactive intermediates can be divided into several categories depending on their half-life under physiological conditions and how far they may be transported from the site of activation. 

Cocaine is metabolized very quickly by the body. Within minutes, enzymes in the blood and in the liver split the cocaine molecule into two halves, rendering it inactive. Cocaine and its metabolites are excreted in the urine. The body s efficient metabolism of cocaine causes the high to be relatively short-lived. This often causes cocaine users to take several doses of cocaine in a short time, which can increase the chances of an overdose. 

Another unique property of hair is the efficient trapping of the short-lived heroin metabolite 6-monoacetylmorphine (6-MAM). " In contrast to hair, this metabolite is rarely found in opiate-positive urines, thereby causing 90% of such urine results to be overturned by medical review officers. The special procedures required for hair analysis to help resolve the opiate-positive problems of urinalysis will be described. 

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