Drugs and Related Agents

Nicotinic receptors are coupled directly to ion channelvrnil when activated by Ach. mediate very rapid responses l-r 

TABLE 17-1 Cations Radii of Alkali and Alkali Earth  

From Tngidc. I). J Nciirotrun miltcf Rcci plor (tiu rjL-tions s ii Dii o, Ai jJk inic W7I 

When the neurotransmitter ACh binds to the nicotinic receptor. it causes a change in the permeability of the membrane to allow passage of small cations CV. Na . and 

Muscarinic receptors play an essential role in regulating the functions of organs innervated by the autonomic nervous system to maintain homeostasis of the organi.sm. The action of ACh on muscarinic receptors con re.sull in. stimulation or inhibition of the organ system affected. ACh stimulates secretions from salivary and sweat glands, secretions and contraction of the gut. and constriction of the airways of the respiratory tract. It inhibits contraction of the heart and relaxes smooth muscle of blood vc.ssels. 

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Langford CP, Barlett R, Haddad LM. 1998. Phenol and related agents. In Haddad LM, Shannon MW, Winchester JF, eds. Poisoning and drug overdose, Philadelphia W.B. Saunders Company. 

Geriatric Considerations- Summary Biperiden is a weak anticholinergic agent which still may present a risk to older adults and can cause cognitive impairment, delirium, dry mouth, blurred vision, and increased risk of falls. The use of this drug and related compounds should be limited and when used, patients should be closely monitored. 

The demonstration of the existence of strictly defined SARs. which is perhaps Ihe most important criterion of drug action at a specific receptor site, has made possible the most important pharmacologic discoveries. For example, the analgesic actions of morphine and related agents, which are indicative of specific receptors, led to die discovery of endogenous opiate peptides, i.e., the leucine and methionine enkephalins and endorphins. 

Szebeni, J. (2001), Complement activation-related pseudoallergy caused by liposomes, micellar carriers of intravenous drugs, and radiocontrast agents, Crit. Rev. Ther. Drug Carrier Syst., 18, 567-606. 

Most cases of unintentional thiazide overdoses can be managed safely at home as serious effects are not expected. Thiazides and related agents are adsorbed by activated charcoal and it may be used for substantial recent exposures. Because cathartics can also cause fluid and electrolyte losses, their use should be avoided. Fluid status, electrolytes, and EKG should be monitored. Standard supportive therapies with attention to replacement of fluid and electrolyte losses should be utilized as clinically necessary. No antidote is available. Drug levels are not readily available and are not helpful in assessing toxicity. 

Atropine and scopolamine are used for pre-medication before the administration of some inhalation anesthetics, to reduce excessive salivary and bronchial secretions. Atropine and related agents have been used in the treatment of renal colic and hyperhidrosis, and to control sweating that may aggravate certain dermatologic disorders. Atropine also may be used to counteract the toxicity of certain cholinergic drugs and anticholinesterase agents. 

The Suzuki cross-coupling reactions have been explored in the synthesis of drugs and related compounds on the laboratory scale but none have been explored on an industrial scale. A few examples given below are AT II antagonist losartan, a COX-2 selective inhibitor, rofecoxib, a highly potent HMG-CoA reductase inhibitor, NK-104, and anticancer agents epothilones A-B. 

Clonidine was one of the first effective antihypertensive drugs. While actions at imidazoline receptors have been postulated (Emsberger et al., 1992), it is likely that clonidine and related agents lower blood pressure via an action... 

Patients with reduced blood volume are considerably more susceptible to the vasodilatory effects of morphine and related drugs, and these agents must be used cautiously in patients with hypotension from any cause. 

MitcheU JR, Cavanaugh JH, Arias L, Oates JA. Guanethidine and related agents. III. Antagonism by drugs which inhibit the ncrepinephrine pump inman. J Clin Invest( 970) 49,159 1604. 

The concepts of stmctuial similarity and CS, which are ubiquitous in medicinal chemistry, are finding a place in other chemically related sciences such as materials science and engineering [185]. A question that now arises is how can we develop procedures and algorithms that exploit these concepts to facilitate the discovery of new drugs and bioactive agents Or, more appropriate to the book in which this chapter resides, how can these concepts be apphed in food science and in aroma and flavor chemistry Although the examples presertted in this section do not represent a comprehensive set of the marty possible methods that are available, they will at least provide a sample that should afford sufficierrt irrformation to help answer this questiom... 

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