Atropine pharmacology

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... 

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. 

This view was supported by the observation that choline on treatment with nitric acid yielded a product having a pharmacological action similar to that of muscarine as known up to that time. Comparison of the natural and artificial products by Bohm showed that the former was much more active than the latter and that its action was antagonised by atropine, whilst the artificial muscarine had a curare-like action on the atropinised frog. Later, Nothnagel investigated the action of... 

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. 

Supraventricular bradycardia is treated by implantation of a pacemaker device or has been treated pharmacologically with atropine. Supraventricular paroxysmal tachycardia is treated with aj marine or praj marine. Supraventricular tachyarrhythmias or AV reentrant arrhythmia typically can be terminated using adenosine. 

Atrioventricular block in general is treated by implantation of an electrical pacemaker. A pharmacological alternative (although no longer used today) was atropine. However, atropine can be used for bridging the time between the onset of symptoms and the definitive implantation of a pacemaker. 

Chapter 1 which showed that since muscarine mimicked some of the actions of ACh (but not all) while nicotine mimicked the other actions of ACh, then ACh probably acted on two distinct types of receptors. The fact that atropine antagonised the muscarinic effects of ACh but not the nicotinic effects, while tubocurarine blocked the nicotinic effects provided firm evidence for this concept. These simple qualitative observations by Langley and others at the beginning of the twentieth century led to the development of more quantitative pharmacological methods that were subsequently used to identify and classify receptors. These methods were based on the use of both (1) agonist and (2) antagonist drugs ... 

Pharmacologically, carbofuran inhibits cholinesterase, resulting in stimulation of the central, parasympathetic, and somatic motor systems. Sensitive biochemical tests have been developed to measure cholinesterase inhibition in avian and mammalian brain and plasma samples and are useful in the forensic assessment of carbamate exposure in human and wildlife pesticide incidents (Bal-lantyne and Marrs Hunt and Hooper 1993). Acute toxic clinical effects resulting from carbofuran exposure in animals and humans appear to be completely reversible and have been successfully treated with atropine sulfate. However, treatment should occur as soon as possible after exposure because acute carbofuran toxicosis can be fatal younger age groups of various species are more susceptible than adults (Finlayson et al. 1979). Carbofuran labels indicate that application is forbidden to streams, lakes, or ponds. In addition, manufacturers have stated that carbofuran is poisonous if swallowed, inhaled, or absorbed through the skin. Users are cautioned not to breathe carbofuran dust, fumes, or spray mist and treated areas should be avoided for at least 2 days (Anonymous 1971). Three points are emphasized at this juncture. First, some carbofuran degradation... 

Parallel with the developments in the benzamide area, progress was also made in several nonbenzamide series of compounds. MDL 72222 (26) [20], atropine ester of 3,5-dichlorobenzoic acid, was the first selective 5-HT3 receptor antagonist and a potent antagonist of cisplatin-induced emesis in the ferret [21]. ICS 205-930 (27) [22,23 ], the tropine ester of 3-indolecarboxylic acid, exhibited similar pharmacological and antiemetic profiles. 

Naunyn-Schmiedeberg s Archives of Pharmacology Figure 10. Blood pressure and heart frequency in an anaesthetized cat with sectioned vagi and pretreatment with atropine (1 mg/kg). Decrease of blood pressure and heart rate in beats/min (S/min) after intracisternal (i.ci.) and intravenous (i.v.) injection... 

The cholinergic hallucinogens all have common chemical constituents that are responsible for their pharmacological effects (Robbers et al. 1996). These are the tropane alkaloids hyoscyamine, scopolamine (or hyoscine), and atropine (figure 9.16). It is scopolamine, and not atropine or hyoscyamine, which primarily produces the central and hallucinogenic effects because it is the only one that passes the blood-brain barrier sufficiently. However, all three have peripheral effects. Datura stramonium contains 0.1-0.65% tropane alkaloids, which is principally... 

Regardless of terminology, one should remember that despite differences in intensity and duration of action, all atropine-like compounds have structural similarities and produce a common pattern of pharmacological effects. In other... 

Physicians also got short shrift. When our group paper on atropine, scopolamine and Ditran won first prize at a pharmacology conference sponsored by the Army Munitions Command, Hank Uhrig didn t even acknowledge the accomplishment. He seemed more interested in the fact that I was not wearing the correct uniform. 

We used an additional analysis to support the estimated LD50/ID50 ratio for BZ. Upon reviewing the LD50 of several glycolates in the mouse, it appeared that the lethality of each closely paralleled its peripheral (as reflected in heart rate changes) rather than central effects (as reflected in performance decrements). This calls into doubt the opinion, voiced in previous textbooks of pharmacology, that death from belladonnoids such as atropine results from respiratory paralysis -primarily a central nervous system effect. 

GK, Hayes AH Jr Atropine, scopolamine and ditran comparative pharmacology and antagonists in man Psychopharmacology (Berlin)2 140-165, 1973. 

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