Atropine Pharmacology


About Atropine
Anti-cholinergic,Belladona alkaloid, Antidote ,Antispasmodic Agent,antiarrythmic,vagolytic , Mydriatic.
Mechanism of Action of Atropine
Atropine is an anticholinergic drug. It selectively inhibits the muscarinic receptors and antagonizes the muscarine like actions of Acetyl choline
Atropine inhibits the muscarinic actions of acetylcholine on structures innervated by postganglionic cholinergic nerves, and on smooth muscles, which respond to endogenous acetylcholine.
Atropine reduces secretions in the mouth and respiratory passages, relieves the constriction and spasm of the respiratory passages, and reduces the paralysis of respiration. 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. Although mild vagal excitation occurs, the increased respiratory rate and occasionally increased depth of respiration produced by atropine are more probably the result of bronchiolar dilatation. Accordingly, atropine is an unreliable respiratory stimulant and large or repeated doses may depress respiration.
Adequate doses of atropine abolish various types of reflex vagal cardiac slowing or asystole. The drug also prevents or abolishes Bradycardia or asystole produced by injection of choline esters, anticholinesterase agents or other parasympathomimetic drugs, and cardiac arrest produced by stimulation of the vagus. Atropine may also lessen the degree of partial heart block when vagal activity is an etiologic factor. In some individuals with complete heart block, the idioventricular rate may be accelerated by atropine; in others, the rate is stabilized. Occasionally, a large dose may cause atrio ventricular (A-V) block and nodal rhythm.
Atropine in clinical doses counteracts the peripheral dilatation and abrupt decrease in blood pressure produced by choline esters. However, when given by itself, atropine does not exert a striking or uniform effect on blood vessels or blood pressure. Systemic doses slightly raise systolic and lower diastolic pressures and can produce significant postural hypotension. Such doses also slightly increase cardiac output and decrease central venous
pressure. Occasionally, therapeutic doses dilate cutaneous blood vessels, particularly in the "blush" area (atropine flush), and may case atropine "fever" due to suppression of sweat gland activity especially in infants and small
General anaesthesia: Once muscle paralysis is no longer desired, acetyl cholinesterase inhibitors are combined with a muscarinic receptor antagonist such as Glycopyrrolate or Hyoscine or Atropine to offset the muscarinic activation resulting from esterase inhibition

Pharmacokinets of Atropine
Absorption: Atropine is well absorbed after parenteral administration. Distribution: It is widely distributed in the body and it crosses the blood brain barrier Metabolism: Atropine undergoes metabolism in the liver. Excretion: It is excreted mainly in the urine and small amount may be excreted in faeces and in expired air.
Onset of Action for Atropine
IM: 5 - 40 minutes
Duration of Action for Atropine
IM: 4 hours
Half Life of Atropine
12 hours
Side Effects of Atropine
1. Dry mouth
3.Difficulty in swallowing
11.Decreased secretions
12.Irritation at the site of injection site
14.Retention of urine

Contra-indications of Atropine
1.Hypersensitivity to Atropine and other belladonna alkaloids
3.Obstructive disease of gastrointestinal tract
4.Obstructive uropathy
5.Unstable cardiovascular status in acute haemorrhage

7.Paralytic ileus
8.Toxic megacolon
9.Intestinal atony
11.Myasthenia gravis
Special Precautions while taking Atropine
1.Any work that require mental alertness like drivingoperating machineAlcoholics
Pregnancy Related Information
Old Age Related Information
Use with caution
Breast Feeding Related Information
Use with caution
Children Related Information
Use with caution
Indications for Atropine
1. Pre anaesthetic medication
2. Symptomatic Bradycardia
3.To block the adverse muscarinic effect of anticholinesterase agents
4.Antidote for anticholinesterase insecticide poisoning
6.Cycloplegic refractions
7.Acute iritis
8.Lessen the degree of AV block
Interactions for Atropine
Typical Dosage for Atropine
Pre anaesthetic medication: (IM) or (SC) 300-600mcg is given 30-60 minutes before surgery.
Bradycardia (IV ): 0.3 - 1 mg dose can be repeated every 3 - 5 minutes 0.03 mg / kg in patient with mild Bradycardia and 0.4 mg / kg with severe Bradycardia,
To block the adverse muscarinic effect of anticholinesterase agents: 0.6 - 1.2 mg for each 0.5 - 2.5 mg of Neostigmine administered intravenously a few minutes before anticholinesterase agents.
Antidote for anticholinesterase insecticidal poisoning: (IM or IV): Initial dose: 1 - 2mg is given and dose can be increased up to 6 mg in severe cases and repeat the dose every 5 - 60 minutes until muscarinic symptoms disappears.
Prevention of Bronchospasm: 0.025 mg / kg is administered with the help of a nebulisers 3 - 4 times daily up to 2.5 mg
Premedication: (IM) or (SC): 20mcg/kg.
Bradycardia (IV): 10 - 20 mcg/kg doses can be repeated up to 1 mg
Antidote for anticholinesterase insecticidal poisoning: (IM or IV): Initial dose: 0.05 mg / kg is given and repeat the dose every 10 -30 minutes until muscarinic symptoms disappears
Schedule of Atropine
Storage Requirements for Atropine
Store at 15 - 30 degree C. Protect from light. Keep out of the reach of children
Effects of Missed Dosage of Atropine
Effects of Overdose of Atropine
Give supportive measures and symptomatic treatment. Physostigmine can be given to reverse the excessive anticholinergic activity produced by Atropine.

Home Delivery for Atropine in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including atropine.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for atropine and other medicines and health products. Home delivery services for atropine may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take atropine only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for atropine before they complete the sale. You can get this information while placing the order for atropine with the pharmacy.

Atropine is a generic medicine name and there are several brands available for it. Some of the brands for atropine might be better known than atropine itself. If the pharmacy that's willing to deliver medicines to your home doesn't have atropine in stock, you can ask for one of the branded alternatives for atropine.