Atropine

pharma for emergency

1. atropine Hamad Emad Hamad Dhuhayr Dr. S ayed Sardar & Prof. Asgher Mehdi

2. Contents 1  Name 2 Medical uses 2.1 Ophthalmic use 2.2 Heart medicine 2.3 Secretions and bronchodilatation 2.4 Organophosphate and nerve agent poisoning 3 Side-effects and overdose 4 Contraindications 5 Mechanism of action

3. Name Atropine  is a naturally occurring  tropane alkaloid  extracted from deadly nightshade ( Atropa belladonna ), Jimson weed ( Datura stramonium ),  mandrake  ( Mandragora officinarum ) and other plants of the family  Solanaceae . It is a  secondary metabolite  of these plants and serves as a  drug  with a wide variety of effects.

4. Natural Sources of Atropine & Hyoscine Atropa belladonna ( Solanaceae) Hyoscyamus niger ( Solanaceae) Datura stramonium

5. Indication Ophthalmic use Topical  atropine is used as a  cycloplegic , to temporarily paralyze the  accommodation reflex , and as a  mydriatic , to dilate the  pupils . Atropine degrades slowly, typically wearing off in 7 to 14 days, so it is generally used as a therapeutic  mydriatic , whereas tropicamide  (a shorter-acting  cholinergic  antagonist) or  phenylephrine  (an α-adrenergic agonist) is preferred as an aid to  ophthalmic examination . In refractive and accommodative  amblyopia , when occlusion is not appropriate sometimes atropine is given to induce blur in the good eye.

6. Heart medicin e Injections  of atropine are used in the treatment of  bradycardia   (an extremely low heart rate). Atropine was previously included in international resuscitation guidelines for use in cardiac arrest associated with  asystole  and  PEA , but was removed from these guidelines in 2010 due to a lack of evidence. For symptomatic bradycardia, the usual  dosage   is 0.5 to 1 mg IV push, may repeat every 3 to 5 minutes up to a total dose of 3 mg (maximum 0.04 mg/kg ). Atropine is also useful in treating  second-degree heart block Mobitz Type 1 ( Wenckebach block) , and also  third-degree heart block  with a high  Purkinje  or  AV-nodal   escape rhythm . It is usually not effective in  second-degree heart block Mobitz type 2 , and in third-degree heart block with a low Purkinje or ventricular escape rhythm.

7. Secretions and bronchodilatation Atropine's actions on the parasympathetic nervous system inhibit salivary and mucus glands. The drug may also inhibit sweating via the sympathetic nervous system. This can be useful in treating  hyperhidrosis , and can prevent the  death rattle  of dying patients. Even though atropine has not been officially indicated for either of these purposes by the FDA, it has been used by physicians for these purposes .

8. Organophosphate and nerve agent poisoning Atropine is not an actual antidote for organophosphate poisoning. However , by blocking the action of  acetylcholine  at  muscarinic  receptors, atropine also serves as a treatment for poisoning by  organophosphate   insecticides  and  nerve gases , such as  tabun  (GA),  sarin  (GB),  soman  (GD) and  VX .

9. Side-effects and overdose Adverse reactions to atropine include ventricular   fibrillation , supraventricular or ventricular  tachycardia ,   dizziness ,  nausea , blurred vision, loss of balance, dilated pupils, photophobia , dry mouth and potentially extreme  confusion , dissociative  hallucinations  and  excitation  especially amongst the elderly. These latter effects are because atropine is able to cross the  blood–brain barrier . Because of the  hallucinogenic  properties, some have used the drug  recreationally , though this is potentially dangerous and often unpleasant .

10. In overdoses, atropine is  poisonous . Atropine is sometimes added to potentially addictive drugs, particularly anti-diarrhea opioid drugs. such as  diphenoxylate  or  difenoxin , where in the secretion-reducing effects of the atropine can also aid the anti-diarrhea effects.

11. Contraindications Myasthenia Gravis , Closed Angle Glaucoma , Dysreflexia , High Blood Pressure , Disease of the Arteries of the Heart, Chronic Heart Failure,   Depression  of the Function of the Heart, Chronic Lung Disease , Down Syndrome, Drowsiness,  Fast Heart beat , Cannot Empty Bladder, Toxin from Microorganisms causing Diarrhea, Overactive Thyroid Gland, Bleeding causing Blood Pressure or Heart Problems Allergies: BELLADONNA ALKALOIDS

12. Mechanism Of Action of Atropine Atropine  and other muscarinic antagonists are competitively binds to receptors with Ach or other agonists.  Muscarinic receptors  are GPCRs. They have 7-helical amino acid structure , the aspartate present on the –NH2 end of the receptor. This form link between agonist/antagonist with the receptor. If concentration of Ach is increased, effect of antagonist overcomes. But chE antagonist along with M-antagonist works in right way.   

13. Absorption Atropine is rapidly and well absorbed after intramuscular administration. Atropine disappears rapidly from the blood and is distributed throughout the various body tissues and fluids. Protein binding The protein binding of atropine is 14 to 22% in plasma. Metabolism Much of the drug is destroyed by enzymatic hydrolysis, particularly in the liver. From 13 to 50% is excreted unchanged in the urine. Route of elimination Much of the drug is destroyed by enzymatic hydrolysis, particularly in the liver; from 13 to 50% is excreted unchanged in the urine. Half life 3.0 ± 0.9 hours in adults. The half-life of atropine is slightly shorter (approximately 20 minutes) in females than males.

14. References http:// www.drugbank.ca/drugs/DB00572 http:// en.wikipedia.org/wiki/Atropine#Medical_uses http://www.webmd.com/drugs/2/drug-6687/atropine-oral/details/list-contraindications