Of atropine

Obtained as a syrup from plants of the Solanaceae family. Intensely poisonous, its action resembles that of atropine. Sedative in small doses. 

Atropine is weU absorbed orally and can be adrninistered parenteraHy. About 50% of an adrninistered dose is metabolized in the Hver, the rest is excreted in the urine unchanged. About 77—94% of an adrninistered dose is excreted in the urine. The pharmacological half-life of atropine is about 2—3 h... 

Isoproterenol. Isoproterenol hydrochloride is an nonselective P-adrenoceptor agonist that is chemically related to NE. It mimics the effects of stimulation of the sympathetic innervation to the heart which are mediated by NE. It increases heart rate by increasing automaticity of the SA and AV nodes by increasing the rate of phase 4 diastoHc depolarization. It is used in the treatment of acute heart block and supraventricular bradyarrhythmias, although use of atropine is safer for bradyarrhythmias foUowing MI (86). 

Agent BZ, 3-quinuchdinylbenzilate [6581 -06-2] C22H23NO2, is a typical incapacitant. BZ is one of a group of substances, many of them glycolate esters, sometimes known as atropinemimetics. Their action on the central and peripheral nervous systems resembles that of atropine [51-55-8] ... 

Hyoscyamine, Ci,H2303N. This, the most commonly occurring alkaloid of the oup, was obtained by Geiger and Hesse from henbane. Ks hydrolysis into a base and an acid was observed by Hohn and Reichardt. The accepted, empirical formula is due to Ladenburg, who s owed that it was a physical isomeride of atropine. Hyoscyamine... 

When heated with acids or alkalis, hyoscyamine undergoes hydrolysis into tropine and dZ-tropic acid probably via conversion into atropine, and it is this alkaloid which is hydrolysed. According to Gadamer, when hyoscyamine is hydrolysed with cold water the products are inactive tropine and Z-tropie acid. Amenomiya has shown that Ladenburg and Hundt s partially synthetic d- and Z-atropines were probably mixtures of atropine with d- and Z-hyoscyamines. He resolved dZ-tropic acid into the d- and Z- forms, esterified these with tropine in 5 per cent, hydrochloric acid, and so obtained d- and Z-hyoscyamines, the latter identical with the natural alkaloid, d- and Z-Hyoscyamines have also been obtained by Barroweliff and Tutin by the resolution of atropine by means of d-camphorsulphonic acid. 

Phenylglycollyltropeine Mandelyltropeine, homatropine), CigHjiOjN. This is largely used as a substitute for atropine. It crystallises in prisms, m.p. 95-5-98-5°. The hydrobromide, the salt usually employed in medicine, is a crystalline powder, m.p. 217-8° (dec.) the hydrochloride, m.p. 224-5°, and the salicylate are also used. All tl ee are freely soluble in water. The methobromide has m.p. 192-6°. The aurichloride, B. HAUCI4, forms prisms and is sparingly soluble in water. Homatropine, unlike atropine, does not give the Vitali colour reaction (p. 70). Its mydriatic effect is more rapid and transient than that of atropine. 

Hyoscine (Scopolamine, Atroscine), Ci,H2i04N. The name hyoscine was first used by Hohn and Reichardt for the basie hydrolytic product of hyoscyamine, now known as tropine. It was subsequently used by Ladenburg for a supposed isomeridc of atropine, Cj HjgOjN, isolated from the mother liquors of hyoscyamine. This was found by Schmidt, Hesse and others to be identical with scopolamine, Ci,H2i04N, obtained by Schmidt from Scopolia japonica. The name hyoscine has priority and is in use, but scopolamine is also employed, especially in Germany. 

These investigations have followed three main lines, (1) alterations in the amino-alcohol nucleus, (2) variation in the alkyl or acyl side-chains, (3) influence of stereoisomerism. Tropine and ecgonine, the basic components of atropine and cocaine, lend themselves to such investigations, but scopine, the amino-alcohol of hyoscine is so labile that systematic modification of this alkaloid has not yet been possible. 

Of the proximate derivatives of atropine, the methobromide and the methonitrate are in use for much the same purposes as atropine, but the methonitrate has received special attention for the treatment of pyloric stenosis. opoAtropine has been found by Mancini to retain the same type of action as atropine but to be less potent in peripheral and more active in central nervous action. ... 

Cushny has compared the action of d- and Z-hyoscyamines with that of atropine, and of d-homatropine with that of dZ-homatropine in antagonising the action of pilocarpine, and finds that the order of activity of the first three is in the ratio 1 40 20, and of the second two in the ratio 4 2-5. He drew attention also to the important influence of the acyl radical in the tropeines, which exercises the maximum effect when it is a hydroxyalkyl aromatic residue and is laevorotatory and in illustration of this point gives the following table of relative activities on the basis of capacity to antagnonise pilocarpine in the salivary fistula dog —... 

Reviews of recent developments in synthetic anti-spasmodics have been published by Raymond and by Blicke, and on the pharmacology of antihistamine compounds by Loew. Mention may also be made of the useful description by Henderson and Sweeten of the effeet of atropine on the gastro-intestinal canal and its glands. 

It resembles atropine in its range of activity but in particular types of action it may differ quantitatively thus its action on the pupil is equal to that of atropine but shorter in duration, and that is also true of its antagonisni to the effect of acetylcholine on the isolated perfused cat s COTt, but its activity on the salivary gland and the blood pressure of the. IS greater than that of atropine, while its action on smooth muscle... 

Pilocarpine is being less used in medicine as a diaphoretic in dropsy and similar diseases because of its depressant action on the heart. It has also been employed as a substitute for physostigmine to contract the pupil and reduce intraocular pressure. It has been used as an antidote to atropine, but it does not antagonise the action of atropine in the central nervous system. 

Burn has pointed out that the grouping together of many properties as fundamentally the same, brings into some sort of order the long list of apparently pharmacologically unrelated alkaloids, and that the similarity in many properties of atropine, papaverine and quinine, and of conessine and quinine, suggests points of biochemical similarity. 

The synthesis of tropinone 14, a precursor of atropine and related compounds, is a classical example. In 1917 Robinson has prepared tropinone 14 by a Mannich reaction of succindialdehyde 11 and methylamine 12 with acetone 13 better yields of tropinone were obtained when he used the calcium salt of acetonedicar-boxylic acid instead of acetone. Modern variants are aimed at control of regio-and stereoselectivity of the Mannich reaction. ... 

Oxidation of ecgonine (2) by means of chromium trioxide was found to afford a keto acid (3). This was formulated as shown based on the fact that the compound undergoes ready themnal decarboxylation to tropinone (4)The latter had been obtained earlier from degradative studies in connection with the structural determination of atropine (5) and its structure established independently. Confirmation for the structure came from the finding that carbonation of the enolate of tropinone does in fact lead back to ecgonine. Reduction, esterification with methanol followed by benzoylation then affords cocaine. 

Reduction of tropanone affords the alcohol epitropanol (13), epimeric with the alcohol obtained on hydrolysis of atropine. 

To a cold solution of 29 g of atropine in 250 ml of acetone a solution of 1 3 g of propane-1,3-sultone in 100 ml of acetone is generally added. The combined solution is left for 48 hours. The white precipitate of fine crystalline needles is separated, washed several times with acetone, and then recrystallized from ethanol. It melts at 220°C. 

Paton, W. D. M., and Rang, H. P. (1965). The uptake of atropine and related drags by intestinal smooth muscle of the guinea pig in relation to acetylcholine receptors. Proc. R. Soc. Lond. [Biot.] 163 1-44. 

Test antagonist = atropine. Reference antagonist = scopolamine. The Schild regression is obtained to the concentrations of scopolamine shown in the left-hand column in the presence of the concentrations of atropine shown in columns labeled Regression I to IV. ... 

The physician orders 0.4 mg of atropine The drug label reads 400 meg per 1 mL This dosage problem is solved by expanding the DA equation by adding one step to die equation. 

Cardiovascular system—palpitations, bradycardia (after low doses of atropine), tachycardia (after higher doses of atropine)... 

Administration of atropine with meperidine (Demerol), flurazepam (Dalmane), diphenhydramine (Benadryl), phenothiazines, and the tricyclic antidepressants may increase the effects of atropine. There is a decreased effectiveness of haloperidol when administered with the anticholinergic dragp. 

Which of the following adverse reactions would the nurse expect after file administration of atropine as part of a patient s preoperative medication regimen ... 

Atropine acts as an antagonist of acetylcholine at muscarinic receptors, but not at nicotinic receptors. By acting as an antagonist, it can prevent overstimulation of muscarinic receptors by the excessive quantities of acetylcholine remaining in the synaptic cleft when AChE is inhibited. The dose of atropine needs to be carefully controlled because it is toxic. 

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