Mydriasis atropine causing

At higher concentrations, atropine causes block of all parasympathetic functions. However, atropine is a remarkably safe drug in adults. Atropine poisoning has occurred as a result of attempted suicide, but most cases are due to attempts to induce hallucinations. Poisoned individuals manifest dry mouth, mydriasis, tachycardia, hot and flushed skin, agitation, and delirium for as long as a week. Body temperature is frequently elevated. These effects are memorialized in the adage, "dry as a bone, blind as a bat, red as a beet, mad as a hatter."... 

Q4 Yes. Rob has used both atropine and phenylephrine this afternoon. Muscarinic antagonists such as atropine, tropicamide and cyclopentolate cause dilation of the pupils. The a-adrenoceptor agonists, such as phenylephrine, also produce my driasis. Mydriasis may cause acute closed-angle glaucoma in some patients. It is unlikely that a very small amount of cocaine in the eye would cause problems, but in cocaine overdose pupils become widely dilated. This is due to blockade of uptake 1, a process normally involved in terminating the effects of noradrenaline. In the presence of cocaine the effects of sympathetic stimulation on the eye would be prolonged and the pupil would dilate. Morphine causes constriction of the pupils via opiate receptors. 

The alkaloid is principally used in medicine to cause dilatation of the pupil of the eye (mydriasis), due to paralysis of the circular muscle of the ns. The accommodation is also paralysed as a result of action on the ciliary muscle (cycloplegia). Atropine is also used in conditions where... 

Inspection of the retina during an ophthalmoscopic examination is greatly facilitated by mydriasis, or the dilation of the pupil. Parasympathetic stimulation of the circular muscle layer in the iris causes contraction and a decrease in the diameter of the pupil. Administration of a muscarinic receptor antagonist such as atropine or scopolamine prevents this smooth muscle contraction. As a result, sympathetic stimulation of the radial muscle layer is unopposed, causing an increase in the diameter of the pupil. These agents are given in the form of eye drops that act locally and limit the possibility of systemic side effects. 

Antimuscarinic drugs block contraction of the iris sphincter and ciliary muscles of the eye produced by ACh. This results in dilation of the pupil (mydriasis) and paralysis of accommodation (cycloplegia), responses that cause photophobia and inability to focus on nearby objects. Ocular effects are produced only after higher parenteral doses. Atropine and scopolamine produce responses lasting several days when applied directly to the eyes. 

Eye. Atropine and similar antimuscarinics block the acetylcholine-mediated contraction of the pupillary sphincter muscle, thus causing dilation of the pupil (mydriasis).1 During an ophthalmologic exam, these drugs may be applied topically in order to dilate the pupil, thus allowing a more detailed inspection of internal eye structures such as the retina. 

Atropine is absorbed orally and crosses the placental barrier, whereupon it causes fetal tachycardia. Atropine has been used to examine the functional integrity of the placenta. Atropine toxicity is characterized by dry mouth, burning sensation in the mouth, rapid pulse, mydriasis, blurred vision, photophobia, dry and flushed skin, restlessness, and excitement. 

Intoxications with higher concentrations will cause tachycardia, mydriasis, CNS excitations and hallucinations, coma and ultimately death [42], Incorporation of atropine (more correctly S-hyoscyamine) is the predominant reason for TA intoxication after ingestion of Datura plants. 

Incidental and accidental intake of atropine and scopolamine, which are the main tropane alkaloids in plants of the solanecae family, may provoke poisoning of man and livestock [11,13-15, 55, 57,119-122] causing agitation, aggression, hallucinations, dry mouth and skin, mydriasis, loss of consciousness followed by coma combined with tachycardia, hypotension, and hyperthermia [57, 121], A detailed statistical analysis of paediatric plant exposures in Germany within the years 1998-2004 has been provided by Pietsch et al. [123], They found that most prevalent victims of accidental plant exposures are children in the age of 1-6 years presumably being misled by the attractive plump berries. 

Atropine is an antidotal treatment. It is used to reverse the muscarinic signs, but it will not reverse the nicotinic effects (muscular weakness, diaphragmatic weakness, etc.). Atropine blocks the effects of accumulated acetylcholine (ACh) at the synapse and should be continued until the nerve agent is metabohzed (Midthng et al, 1985). Over-atropinization can cause hyperthermia, tachycardia, agitation, mydriasis, and ileus, which can be life threatening in the horse (Meerstadt, 1982). 

Systemically administered atropine may also cause mydriasis and raise lOP in patients with open-angle glaucoma. After intramuscular injection of 0.6 mg atropine, three of eight patients developed 0.5- to 1.5-mm mydriasis. A mean increase of 0.8 cm in the near point of accommodation after atropine administration was also reported. 

The belladonna alkaloids are absorbed rapidly from the gastrointestinal tract. They also enter the circulation when applied locally to mucosal surfaces. Only limited absorption occurs from the intact skin. Atropine disappears rapidly from the blood and is distributed throughout the entire body. Most is excreted in the urine within the first 12 h, in part unchanged. Only about 1% of an oral dose of scopolamine is eliminated as such in the urine. Traces of atropine are found in various secretions, including milk. The total absorption of quaternary ammonium derivatives of the alkaloids after an oral dose is only about 10-25 percent (10,11) nevertheless, some of these compounds can cause mydriasis and cycloplegla if applied to the eye. 

Pethidine causes vomiting about as often as does morphine it has atropine-Hke effects, including dry mouth and blurred vision (cycloplegia and sometimes mydriasis, though usually nviosis). Overdose or use in renal failure can cause central nervous system stimulation (myoclonus, convulsions) due to norpethidine. 

Hyoscine (scopolamine) is structurally related to atropine. It differs chiefly in being a central nervous system depressant, although it may sometimes cause excitement. Elderly patients cire often confused by hyoscine and so it is avoided in their anaesthetic premedication. Mydriasis is also briefer than with atropine. 

Atropine is the racemic mixture of l- and o-hyoscya-mine and possesses 50% of the antimuscarinic potency of L-hyoscyamine. Atropine is derived from components of the Belladonna plant and is also present in other plants from the Solanaceae family. Women in ancient times often dripped the plant s juices into their eyes, causing mydriasis and thereby enhancing their beauty. In Italian, Belladonna translates to beautiful lady . In the United States, the atropine autoinjector has been in use since 1973 for the treatment of exposures to chemical warfare nerve agents and insecticides. 

Another condition that could be confused with botulism is nerve agent and/or atropine poisoning (28). Unlike botulinum toxin, which results in decreased secretions, nerve agent poisoning (see Chap. 3) causes patients to develop copious respiratory secretions and miotic pupils. As compared to the clear sensorium of botulism patients, atropine overdose causes nervous system excitation, including hallucinations and delirium, even though the mucous membranes are dry and patients have mydriasis (see Chap. 3). 

The acute poisoning that occurs with most antihistaminics does not cause severe CNS depression as would be expected based on their sedative properties, but is manifested by mydriasis, fever, flushing, CNS excitement, hallucinations, ataxia, athetosis, and convulsions. Some of these effects, which resemble those of atropine poisoning, may be due to their anticholinergic properties. Diazepam is an effective antidote to poisoning and should be used to reverse the CNS excitement and convulsions. 

By far the most sensitive test for atropine, Z-hyoscyamine, and Z-scopolamine is their ability to produce mydriasis of the pupil of the eyes of young cats, dogs and rabbits (1). An aqueous, alcohol-free solution of the alkaloid, its sulfate or acetate which must be almost neutral is used. It is dropped into the conjunctival sac of the eye and held so that none is lost by overflow of tears (252). It has been reported (1) that 1 part in 40,000 or that 0.000,000,427 g. of atropine sulfate will cause a distinct dilation of the pupil of the eye in 1 hour. Besides the tropane alkaloids certain digitalis preparations and the volatile base, coniine, possess this same property. Tropine, the basic cleavage product of atropine and Z-hyoscyamine, has no effect upon the eye if administered in the normal way but does possess mydriatic properties when administered internally (252). 

Muscarinic cholinoceptor blocker prototype lipid-soluble, CNS effects. Tox red as a beet, dry as a bone, blind as a bat, mad as a hatter, urinary retention, mydriasis. Cyclopentolate, tropicamide antimuscarinics for ophthalmology shorter duration than atropine (a few hours or less) cause cycloplegia and mydriasis. 

Cyclopentolate hydrochloride is usually employed as eye drops to cause cycloplegia and mydriasis. It acts much faster than atropine and possesses a relatively shorter duration of action. 

The drug a tertiary amine hydrobromide, causes both mydriasis and cycloplegia. However, its duration of action seems to be much shorter and rapid when compared to those of atropine and perhaps it may be the reason why it is preferred for such purposes. 

When given to a normal individual (one without nerve agent intoxication), a dose of 2 mg of atropine will cause an increase in heart rate of about 35 beats per minute (which usually is not noticed by the recipient), a dry mouth, dry skin, mydriasis, and some paralysis of accommodation. Most of these effects will dissipate by 4 to 6 hours, but near vision may be blurred for 24 hours, even in healthy young men. The decrease in sweating caused by 2 mg of atropine is a major, potentially harmful side effect that may cause some people who work in the heat to become casualties. For example, when 35 soldiers were given 2 mg of atropine and asked to walk for 115 minutes at 3.3 mph at a temperature of about 83°F (71°F wet bulb), more than half dropped out because of illness or were removed from the walk because of body temperature of 103.5°F or above on another day, without atropine, they all successfully completed the same march.129... 

Pilocarpine is used as its hydrochloride and possesses excitatory activity on the parasympathetic nerve system, like physostigmine (Section 2.5) and arecoline (Section 10.3). Thus, this alkaloid acts as an antagonist of atropine (Section 3.2), and it promotes the secretion of sweat, saliva, and tears and causes myosis. It is reported that subcutaneous injection of 10 mg of pilocarpine HCl causes violent sweating (0.5-1.01) and salivation (11). As an eye lotion, a 1% solution of pilocarpine HCl is used for recovery from the mydriasis caused by atropine, or for the treatment of glaucoma. 

Introduction of a 0.01% solution of aceclidine into the conjunctival sac of rabbits reduced the pupil diameter on the average by 3 mm, the maximum myotic effect appearing in 20-30 minutes and having a duration of 1.5-2 hours. A 0.1% solution caused reduction of the pupil diameter by 5 mm and maximum myosis was produced by a 5-10% solution [122]. Administration of a 2% solution of aceclidine to rabbits 60 minutes after administration of a 2% solution of atropine sulphate removed mydriasis completely, the latter reappearing after 5 hours [127]. Aceclidine did not cause local anaesthesia [127]. After administration of a solution of aceclidine hydrochloride to rabbits the compound could be detected in the animal s blood serum [127]. Administered subcutaneously to rats at a dose of 25-50 mg/kg aceclidine caused intense salivation, lacrimation (chromodacryorrhea) and diarrhoea. Toxic doses produced tremors and convulsions. The acute LDgQ in rats was 45 mg/kg on intravenous administration, 225 mg/kg on subcutaneous administration [122] and 105 mg/kg when administered intraperitoneally [127]. The acute LDgo for white mice was 36 mg/kg, i.v. 112.5 mg/kg, s.c. and 165 mg/kg when administered per os [122]. In rabbits aceclidine at doses of 1 mg/kg i.v., 10 mg/kg s.c. and 25 mg/kg per os caused intense salivation, myosis and diarrhoea. 

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