Pulmonary agents persistency

Pulmonary agents have been absorbed into porous powders (e.g., pumice) and disseminated as dust clouds. The agents are slowly released by the dust particles thereby greatly increasing the persistency of the agents. 

Tolazoline, an alpha-adrenergic-receptor-blocking agent with vasodilating properties (1 to 2 mg/kg IV via a scalp vein over 10 minutes), is indicated in persistent pulmonary vasoconstriction and hypertension of the newborn (persistent fetal circulation). 

The most common agents in modern arsenals are vesicants and nerve agents. Cyanides and pulmonary toxicants are thought to be represented in some stockpiles, but are typically less toxic and more difficult to employ because of their physical characteristics. Some cyanides and pulmonary toxicants have specific characteristics that make them appropriate for military use, such as rapid rate of action, very low persistency, and the ability to penetrate or damage protective equipment. 

Simple 2-benzylimidazoIines (30-33) were prepared by condensation of the appropriate phenylacetonitrile (29) with ethylenediamine either at elevated temperatures or in the presence of catalytic amounts of carbon disulphide Scheme 5.9.). Tolazoline was also prepared in high yield by Neefs method [24]. Tolazoline (30) [25, 26] is a vasodilator but, domazoline (31) [27], xylometazoline (32) [28] and oxymetazoline (33) [29] are all vasoconstrictors. Oxymetazoline was shown to be an agonist for both pre- and post-synaptic a2-adrenergic receptors [30], Tolazoline can be used in animals to give rapid arousal from anaesthesia, for example it is reported to reverse the effect of xylazine with ketamide in wolves [31], white tailed deer [32] and elephants [33], in each case it was fully effective and caused no distress to the animals. It is useful in neonates such as lambs and calves to treat persistent foetal circulation syndrome (persistant pulmonary hypertension) [34] and is recommended for the same condition in human newborns [35, 36]. Oxymetazoline found use in dentistry as a gingival retraction agent [38]. 

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