Jagadeeswaran Appusamy

Pharmacological terms used for drugs acting on various systems 1. Drugs acting on mouth and salivary glands a. Sialogogues / Sialics : These are drugs which increase the secretion of saliva. They may act either directly upon the gland or their secreting nerves or may act reflexly. i.               Direct sialogogues : Eg. Pilocarpine, Physostigmine. ii.             Reflexly acting sialogogues : Eg. Alcohol, Acids, Bitters and Aromatics. Through sensory nerve ending in the mouth or through the stomach. Eg. Ipecacuanha, Antimony. b. Antisialics : are drugs which diminish the secretion of saliva. i.               By paralysing secretary nerve endings. Eg. Atropine ii.              Acting by decreasing irritation of the bucc...

DRUG-INDUCED HYPERSENSITVITY REACTIONS Hypersensitivity or "allergic" reactions to drugs do not appear to have a high incidence in veterinary medicine (perhaps <10% of all drug-related ad­verse effects). Nevertheless immune-mediated responses due to the antigenic properties of some drugs can lead to serious and even fatal consequences. Hypersensitivity in animals has been associated most frequently with penicillins and cephalosporins but tetracyclines, chloramphenicol, sulfonamides, macrolides, lincosamides, nitrofurans, isoniazid, levamisole, corticosteroids, protein hormones, iodinated contrast media for use in radiography, and several other drugs may precipitate various forms and degrees of immune-based reac­tions. In addition, several carriers and solubilizers are also capable of bringing about the sudden release or activation of autacoids such as histamine, serotonin, kinins, prostaglandins, leukotrienes, and platelet-activating factor, leading to clinical s...

FACTORS MODIFYING THE ACTION AND FATE OF DRUGS Following the selection of a specific therapeutic agent to treat a disease condition that has been diagnosed in a particular patient, an appropriate phar­maceutical form of the drug is administered by a predetermined route at the recommended dose rate and frequency. The expectation is that the desired pharmacological response will occur for a known time period without any ex­traneous reactions. However, unanticipated effects can occur following the de­livery of almost any drug into an animal's body. Drug-induced reactions may be exaggerated (hyperresponsiveness) or of reduced magnitude (hyporesponsiveness) compared to those that would normally result from the dosage employed. Such effects may become evident either immediately or over time, and are not necessarily directly related to the drug's main pharmacodynamic action. Sec­ondary pharmacological actions can become the dominant clinical feature and thereby obscure the p...