Why Atropine Is Contraindicated In Horse?

Frequent administration of topical atropine may cause decreased intestinal motility and colic in horses due to systemic exposure. Atropine pharmacokinetics are unknown in horses and this knowledge gap could impede the use of atropine because of the presumed risk of unwanted effects.

Why should atropine be used cautiously in horses?

Atropine should be used with caution, because even low doses may cause tachycardia, ileus, neurologic derangement, and blurred vision in horses. Glycopyrrolate is twice as potent as atropine in humans and does not cross the blood-brain barrier.

Is atropine contraindicated in horses?

The horse, especially, seems more sensitive to atropine as a dose of more than 0.01 mg/kg subcutaneously can give adverse effects. Indeed, by its paralytic effect on the gastro-intestinal tract, severe colic can be provoked.

Why are anticholinergics contraindicated for horses?

Anticholinergic administration is contraindicated in horses with bradycardia due to α₂-adrenergic agonist administration because anticholinergics can trigger arrhythmias and bradycardia is the body’s natural response to the vasoconstrictive action of α₂-adrenergic agonists.

In what conditions is atropine contraindicated?

Atropine generally is contraindicated in patients with glaucoma, pyloric stenosis, thyrotoxicosis, fever, urinary tract obstruction and ileus.

What are main adverse effects of atropine?

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• Bigger, dilated, or enlarged pupils.
• blindness.
• chest pain, discomfort, or tightness.
• decreased vision.
• decrease in urine volume.
• decrease in frequency of urination.
• difficulty in passing urine.
• eye pain.

What are the side effects of atropine in animals?

Atropine may decrease tear production. If the pet receives too much atropine, dry mouth, constipation and vomiting may occur along with changes in heart rate and rhythm, increase in body temperature and the inability to urinate. Other side effects may occur. If you notice anything unusual, contact your veterinarian.

Which is the most severe side effect of atropine?

Excess doses of atropine sulfate may cause side effects such as palpitations, dilated pupils, difficulty swallowing, hot dry skin, thirst, dizziness, restlessness, tremor, fatigue, and problems with coordination.

Why does atropine worsen heart block?

Since the actions of atropine are to block the binding of acetylcholine to muscarinic receptors, thereby (a) reducing vagal input at the SA node, and (b) increasing conduction velocity through the AV node, the thought is that atropine would be a poor choice for reducing oxygen demand in heart-block therapy when an MI

Why are anticholinergics not routinely used in equine anesthesia?

ANTICHOLINERGIC DRUGS
Atropine has a prolonged duration of action of many hours in the horse and may produce gastrointestinal problems such as impaction colic, particularly of the cecum.

What does atropine cause in horses?

Introduction: Atropine is an essential part of the treatment protocol for equine uveitis. Topical atropine administration has been associated with decreased intestinal motility and abdominal pain in horses. Experimental studies have indicated that frequent dosing is associated with a higher risk than dosing every 6 h.

What is a contraindication to anticholinergics?

Possible Contraindications
Anticholinergic medications should be used with caution in people over 65 years of age or with dementia. In addition, the following conditions may worsen with the use of anticholinergics:4. Glaucoma. Hyperthyroidism. Prostate Hypertrophy.

What are anticholinergics contraindicated with?

Also, people with the following conditions shouldn’t use anticholinergics: myasthenia gravis. hyperthyroidism. glaucoma.

What is the antidote of atropine?

Physostigmine, given as an atropine antidote by slow intravenous injection of 1 to 4 mg (0.5 to 1 mg in pediatric populations), rapidly abolishes delirium and coma caused by large doses of atropine.

What is the mechanism of action of atropine?

Mechanism of Action:
Atropine 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.

Why atropine causes increase heart rate?

Atropine increases the heart rate and improves the atrioventricular conduction by blocking the parasympathetic influences on the heart.

What is atropine toxicity?

In overdose, atropine can cause tachycardia, agitation, delirium, dilated pupils, dry mucous membranes, dry skin, and hypoactive bowel sounds. These phenomena have been described even with attempted therapeutic ophthalmic use.

Why is atropine not used?

Atropine is only useful to counter muscarinic effects (pralidoxime and benzodiazepines act on the others). If there are local symptoms to the eyes or respiratory tract, atropine is not indicated. Intravenous (IV) atropine indications include patients with hypersalivation, bronchial secretions, or bradycardia.

Does atropine decrease heart rate?

Low-dose atropine slows heart rate but does not change overall levels of MSNA. High-dose atropine causes a decrease in MSNA and tachycardia.

What is atropine used for veterinary?

For use in Dogs and Cats as an antidote in the treatment of organophosphate insecticide poisoning; to reduce salivation, bronchial secretions or intestinal peristalsis associated with colic or diarrhea, and as a preanesthetic adjuvant.

Does atropine cause respiratory muscle paralysis?

Conclusion: It is suggested that the cause of respiratory muscle paralysis may be related to high dose of atropine.