Atropine-induced parasympathetic inhibition may be preceded by a transient phase of stimulation, especially on the heart where small doses first slow the rate before characteristic tachycardia develops due to paralysis of vagal control. Pharmacodynamics:Ītropine reduces secretions in the mouth and respiratory passages, relieves the constriction and spasm of the respiratory passages, and may reduce the paralysis of respiration which results from actions of the toxic agent on the central nervous system. Pralidoxime also slows the process of "aging" of phosphorylated cholinesterase to a non-reactivatable form and detoxifies certain organophosphates by direct chemical reaction. The destruction of accumulated acetylcholine can then proceed and neuromuscular junctions will again function normally. The principal action of pralidoxime is to reactivate cholinesterase (mainly outside the central nervous system) which has been inactivated by phosphorylation due to an organophosphorous nerve agent or related compound, although pralidoxime does not reactivate cholinesterase inactivated by all organophosphate nerve agents (e.g. Responses to postganglionic cholinergic nerve stimulation may also be inhibited by atropine but this occurs less readily than with responses to injected (exogenous) choline esters. The receptors antagonized by atropine are the peripheral structures that are stimulated or inhibited by muscarine,( i.e., exocrine glands and smooth and cardiac muscle). As with other antimuscarinic agents, the major action of atropine is a competitive or surmountable antagonism which can be overcome by increasing the concentration of acetylcholine at receptor sites of the effector organ (e.g., by using anticholinesterase agents which inhibit the enzymatic destruction of acetylcholine). More precisely, however, it is termed an antimuscarinic agent since it antagonizes the muscarine-like actions of acetylcholine and other choline esters.Ītropine inhibits the muscarinic actions of acetylcholine on structures innervated by postganglionic cholinergic nerves, and on smooth muscles which respond to endogenous acetylcholine but are not so innervated. ATNAA - Clinical Pharmacology Mechanism of Action:Ītropine is commonly classified as an anticholinergic or antiparasympathetic (parasympatholytic) drug. The chloride salt is preferred because of physiologic compatibility, excellent water solubility at all temperatures, and high potency per gram, due to its low molecular weight. The specific activity of the drug resides in the 2-formyl-1-methylpyridinium ion and is independent of the particular salt employed. Its empirical formula is C 17H 23NO 3 and its structural formula is: Chemically, atropine is designated as 1]H,5]H-Tropan-3]-ol (])-tropate. Atropine, a naturally occurring belladonna alkaloid, is a racemic mixture of equal parts of d- and I- hyoscyamine, whose activity is due almost entirely to the levo isomer of the drug. It is slightly soluble in water, soluble in glycerin and ether, and freely soluble in alcohol and chloroform with a molecular weight of 289.38. The pH range is 2.0-3.0.Īfter a ATNAA has been activated, the empty container should be disposed of properly (see DOSAGE AND ADMINISTRATION).It cannot be refilled, nor can the protruding needle be retracted.Ītropine, an anticholinergic agent (muscarinic antagonist), occurs as white crystals, usually needle-like, or as a white, crystalline powder. The pH is adjusted with hydrochloric acid. The pH range is 4.0 - 5.0.Ħ00 mg of pralidoxime chloride in 2 mL of a sterile, pyrogen-free solution containing 40 mg benzyl alcohol, 22.5 mg glycine, and Water for Injection. The recommended procedure (see DOSAGE AND ADMINISTRATION) is to inject the contents of the auto-injector into the muscles of an outer thigh or into the buttocks.Ģ.1 mg atropine in 0.7 mL of a sterile, pyrogen-free solution containing 12.47 mg glycerin and not more than 2.8 mg phenol, citrate buffer, and Water for Injection. When activated, the ATNAA sequentially administers atropine and pralidoxime chloride through a single needle. The ATNAA is a specially designed unit for automatic self-or buddy-administration by military personnel. The Antidote Treatment - Nerve Agent, Auto-Injector (ATNAA) provides Atropine Injection and Pralidoxime Chloride Injection in separate chambers as sterile, pyrogen-free solutions for intramuscular injection. FOR USE IN NERVE AGENT POISONING ONLY STERILE SOLUTIONS FOR INTRAMUSCULAR USE ONLY ATNAA Description
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |