Nicotine administration routes

The studies summarized above indicate that while nicotine has sexually dimorphic effects on cognitive processes, no generalizations can be made. The effects depend on the type of test and performance measures as well as on the route and regimen of nicotine administration. Eurthermore, the species, strain and age of animals, motivation, and mood would have substantial impact on the cognitive effects of nicotine. 

Tumkosit P, Kuryatov A, Luo J, Lindstrom J (2006) Beta3 subunits promote expression and nicotine-induced up-regulation of human nicotinic alpha6 nicotinic acetylcholine receptors expressed in transfected cell lines. Mol Pharmacol 70 1358-1368 Turner DM (1975) Influence of route of administration on metabolism of [14C]nicotine in four species. Xenobiotica 5 553-561... 

Drugs may be solid at room temperature (eg, aspirin, atropine), liquid (eg, nicotine, ethanol), or gaseous (eg, nitrous oxide). These factors often determine the best route of administration. The most common routes of administration are described in Chapter 3. The various classes of organic compounds—carbohydrates, proteins, lipids, and their constituents—are all represented in pharmacology. 

Selectivity of action is based on several factors. Some drugs stimulate either muscarinic receptors or nicotinic receptors selectively. Some agents stimulate nicotinic receptors at neuromuscular junctions preferentially and have less effect on nicotinic receptors in ganglia. Organ selectivity can also be achieved by using appropriate routes of administration ("pharmacokinetic selectivity"). For example, muscarinic stimulants can be administered topically to the surface of the eye to modify ocular function while minimizing systemic effects. 

Transdermal administration can avoid first-pass metabolism as well as provide a large surface area for continuous-controlled administration of drugs with short biological half-lives and narrow therapeutical indices. The route has been used for nitroglycerin ointments, and transdermal therapeutical systems (patches) have been developed for scopolamine, nitroglycerin, clonidine, estradiol, and nicotine. 

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