Rapidity of action

Formaldehyde is available as a 40% w/v solution in water (100% formalin). An 8% formaldehyde solution in water has a broad spectrum of activity against bacteria, fungi, and viruses. Sporicidal activity may take as long as 18 hours. Its rapidity of action is increased by solution in 70% isopropanol. Formaldehyde solutions are used for high-level disinfection of hemodialyzers, preparation of vaccines, and preservation and embalming of tissues. The 4% formaldehyde (10%... 

In common with other indole derivatives, reserpine is susceptible to decomposition by light and oxidation, so it must be stabilized. Modifying the trimethoxyphenyl portion of the molecule gives other antihypertensive drugs with various potency and rapidity of action. 

Speed of Action — Tlie next most important tactical requirement is rapidity of action. Some substances act with remarkable speed in pmducing effects upon the body while others act very slow ly, and their effects are not noticeable until many hours after exposure. Thus, HCN acts with almost lightning rapidity when present in lethal concentrations. One or two full breaths of this gas are sufficient to cause instant collapse and death within a few minute.. On the other hand, mustard gas is very slow acting and, in usual field concentTations, does not produce noticeable symptoms until several hours after exposure. 

On short exposures (t.e., le.ss than 5 minutes), ethyidichlorarsine is not a particularly efficient irritant for the human skin. On exposures greater than 5 minutes, however, positive bums appear which increiv. in severity with lengtii of exposure. On the basis of rapidity of action, extent of rubefaction, swelling and edema, and time of healing, ethyidichlorarsine is about t vo-tliird.s as effective as mustard gas, but for vesication it is only about o ie-sixth as effective. 

Considering the factors (1) rapidity of action (2) extension of rube-faction,. swelling, and edema and (3) time of healing of lesions, the World War vesicants and thoso compounds having sub.sidiary vesicant action may be arranged in descending order of their skin-irritant efficienc>-ius follows ... 

Several AOPs have been proposed to operate carbofuran decomposition, and many of them have demonstrated their effectiveness. The choice ofthe more appropriate system will consider parameters like the rapidity of action and economical factors. 

Reactive decontaminants are likely to be preferable, under some circumstances, because of their rapidity of action and the complete removal of the toxic material that they offer. Yang et al. (1992) identified two key reactions that are made use of in decontamination, i.e. hydrolysis, and oxidation. Two sub-categories - catalytically-enhanced and enzyme-enhanced hydrolysis were also identified. These authors discussed a variety of media - aqueous, organic and solid - in which these reactions could occur. 

Shih et al. (2003) evaluated the potency and rapidity of action of some anticholinergics, including atropine and two benzodiazepines (diazepam and midazolam), for seizures produced... 

Braitman (1989) found that CN (10-200 pM) rapidly depressed synaptic transmission between Schaffer collateral-commissural fibres and pyramidal cells. Analysis of input/output curves revealed both a decrease in excitatory postsynaptic potential generation and an increase in action potential threshold these suggested that the rapidity of action was due to a direct effect on CNS neurones. However, most studies emphasize a role for biochemical mechanisms as being mainly responsible for neurotoxicity. 

Metopon is satisfactory as a drug for oral use in the relief of chronic pain, but it is difficult and costly to prepare and therefore has not become a widely used substitute of morphine. Morphine, because of its cheapness, reliability, and rapidity of action, remains the drug of choice for conditions requiring relief of severe pain for periods of less than 2 weeks. Over a longer period, metopon and methadon may be more suitable drugs. 

It was concluded that LC50 values gave a relative ranking of the materials significantly different from that obtained from the time-to-death values. This is not surprising since the latter is a measure of the rapidity of action while LC50 refers to... 

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