Secondary Pharmacological Action

Ixxtal anesthetics do not rely on blood circulation to reach their site of action, as they are usually administered at. or close to. their site of action. Systemic side effects ari.se be-caiLse the local anesthetic agent is carried away in the blood hefure it can be fully metabolized. Con.sequently. the chemi-ciil iind pharmacological properties of local anesthetics arc of major importance in determining not only the effectiveness of the drug but also its systemic. side effects. 

Local anesthetic agents can affect the function of any organs in which electrical impulse transmi.ssion occurs. The nature and the extent of the.se unwanted side effects depend on the drug u.sed, the concentration of the drug in circulation, the site of application, and the technique used. The. secondary effects of local ane.sthelic agents in lhe.se situations are discussed in this. section. 

Other types of local anesthetic can stimulate the CNS system but often lead to drowsiness. Individual compounds may cause other unwanted side effects, however. For example, at bhxxl concentrations of S /zg cm. lignocaine may produce muscle twitching, dysphoria, and euphoria. Both lignocaine and procaine can pnxluce symptoms of sedation, followed by unconsciousness. Cocaine, in common with some other local anesthetic agents, has an effect on nuuxl and behavior. 

Local ane.sthelics may interfem with wound healing. This is particularly important in surgery carried out on the hands and feel. 

Hypersensitivity to local anesthetics appears to be related to both chemical structure and the method of administration. Allergic reactions occur most frequently with csler-ba.sed local anesthetic agents (benzoic acid derivatives). Adverse effects include allergic dermatitis, asthmatic attack, or. in extreme cases, death due to anaphylactic shock. Individuals suffering a hypersensitive reaction from one local anesthetic agent are often sensitive to compounds with a. similar structure. For example, patients semsilive to procaine arc often also sensitive to amethocaine 

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Secondary actions - studies related to secondary pharmacological actions of the new drug which may be relevant to expected use or to adverse effects of the new drug. ... 

Additional (secondary) pharmacological actions (e.g. prolongation of the QT interval on the electrocardiogram - many drugs)... 

Secondary amine TCAs (e.g., nortriptyline, desipramine) are better tolerated and somewhat safer than their tertiary amine parent compounds (e.g., amitriptyline, imipramine) (407, 408). This is due to differences in the relative potencies of several pharmacological actions, which include their binding affinity for the following ... 

Secondary parkinsonism Parkinsonian symptoms infrequently follow viral encephalitis or multiple small vascular lesions. Drugs such as the phenothiazines and haloperidol (see p. 127), whose major pharmacologic action is blockade of dopamine receptors in the brain, may also produce parkinsonian symptoms. These drugs should not be used in parkinsonian patients. 

Interactions resulting from the use of two drugs with opposing effects should be among the easiest to detect. However, opposing pharmacological actions are sometimes caused by the secondary effects of certain drugs, and this and other factors may preclude early identification of such situations. 

For some time now several research laboratories have been intensively researching this family, inspired by its broad and varied botanical distribution, the interesting chemical nature of its secondary metabolites, the complexity of the biogenetic processes which produce diem, and most of all by the different types of pharmacological action displayed by preparations of its constituents. In Latin America (Mexico, Central America, the Caribbean and South America) this study is particularly momentous due in the main to a socio-economic and cultural climate which has not in the past lent itself either to sound development or the rational exploitation of the resources of the various countries involved. 

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