Atropine

1. ATROPINE DR GEETANJALI S VERMA DR GEETANJALI VERMA

2. ANTI CHOLINERGICS Natural : Atropine , Scopolamine Semisynthetic : Homatropine , Atropine methonitrate , H yoscine butylbromide , I pratropium bromide, T iotropium bromide Synthetic : C yclopentolate , T ropicamide , O xybutinin , T rihexphenidyl , G lycopyrrolate DR GEETANJALI VERMA

3. Origin: Atropa belladona Datura stramonium Ester of tropic acid and tropine MoA Block muscarinic effects of Ach (competitive antagonist) Do not interfere with release of Ach at cholinergic nerve endings Does not distinguish between the M 1 , M 2 , and M 3 DR GEETANJALI VERMA

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5. PHARMACOKINETICS A bsorbed from the gut, parenteral sites and mucous membranes Distribution : widely distributed in the body Metabolism : in liver (conjugation) 60 % excretes unchanged in urine Effects disappear quickly within 2 Hrs except eye Crosses placental barrier & secreted in milk & saliva DR GEETANJALI VERMA

6. PHARMACODYNAMICS SECRETIONS Salivary: dry mouth, difficult swallowing Gastric: reduces vol & total acidity Psychic, gastric & intestinal phases of gastric secretion blocked partially Reduced secretion of mucin & gastric enzymes Others: Reduces secr in nose, mouth, pharynx, bronchi (viscid) Decr sweat No lacrimal inhibition Little effect on pancreatic & intestinal juices & bile DR GEETANJALI VERMA

7. SMOOTH MUSCLE GI Reduces tone & motility (antispasmodic) Doesn’t interfere significantly with normal peristalsis Biliary tract : weak anti spasmodic Urinary tract: reduce tone of fundus of bladder & enhance tone of trigonal sphincter -- uri retention Bronchi: relaxes musc of bronchi & bronchioles Uterus : - Eye: mydriasis (sphincter of iris & ciliary musc ) – paralysis of accomodation or cyclopegia DR GEETANJALI VERMA

8. CVS Initially decreases HR – partial agonist of Ach or stimulation of vagal nuclei Foll by tachy (↑ by 30-40 bpm ) – blocking of M2 ® in SA node Toxic doses: dilatation of cutaneous blood vessels – atropine flush & hypotension (depression of vasomotor center or periph vasomotor paralysis) DR GEETANJALI VERMA

9. CNS Mild stimulation of medullary vagal nuclei & higher cerebral centres – ↓HR,↑ rate & depth of resp Toxic doses: marked excitation Mod doses: controls tremors & rigidity in parkinsonism DR GEETANJALI VERMA

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12. ADVERSE EFFECTS Due to extension of its pharma actions Dryness of mouth, difficult swallowing tachycardia Fever Constipation Blurring of vision, ppts glaucoma (elderly) Retention of urine (elderly) Local allergy: dermatitis, conjunctivitis, swelling of eyelids Drugs causing synd of acute atropine intox : TCAs, phenothiazines , anti histaminics DR GEETANJALI VERMA

13. ACUTE BELLADONA POISONING Lethal dose: children 10-30mg, adults: 80-130mg Periph muscarinic blockade Dryness of mouth, difficult swallowing, thirst Tachy , palpitations Hyperpyrexia ( inhibitino of sweating) Dil of pupils, blurred vision, photophobia Uri urgency, difficult micturition , retention Rash –face, neck , upper trunk Central actions Excitement, restlessness Motor incoord Slurring of speech, memory disturbance Confusion, hallucination, mania, delirium n/v, HTN Coma, paralysis of resp centre DR GEETANJALI VERMA

14. Diagnosis Adding drop of pt’s urine in cat’s eye pupillary dilatation t/t: Ingestion: gastic lavage Physostigmine 1-4mg (children 0.5-1mg) IV ( pref in CNS symp ) Neostigmine 2-5mg sc Repeated at intervals of 1-2hrs Other symptomatic mgmt (dark room, tepid sponging, oxygen, artificial vent, catheterisation ) DR GEETANJALI VERMA

15. PREPARATIONS Belladona dry extract (1%) Belladona tincture : dose 0.6-2ml Atropie sulfate 0.5 mg tab or powder 0.25-2mg Atropine eye oint 1% Atropine sulfate inj 0.5mg in 1ml Atropine methonitrate (0.6% alcoholic soln in dose 0.2-0.6mg) DR GEETANJALI VERMA

16. USES GI Biliary colic (morphine) Cystitis (allay freq & urgency) Ocular Fundosc examn Acute iritis Iridocyclitis Keratitis DR GEETANJALI VERMA

17. Pre anesth med: Reduce secretions OP poisioning Parkinsonism CVS: AV block, hypersensitive carotid sinus (counters syncope & brady ) Uri incontinence DR GEETANJALI VERMA

18. CONTRAIND Age > 40yrs (acute congestive glaucoma) Enlarged prostate (retention) Chronic lung condn Congestive cardiac condn Pyloric obstr , pylorospasm , cardiospasm DR GEETANJALI VERMA

19. THANKYOU DR GEETANJALI VERMA