cimetidine

1. Cimetidine Presented By: Submitted To: Sir Irfan Hamid

2. Drug name : Cimetidin Pharmacological class: Histamine H2 Antagonists Enzyme Inhibitors Therapeutic class: Anti-Ulcer Agents Cimetidine

3. Guanidine, N-cyano-N'-methyl-N''-[ 2-[[(5-methyl-1H-imidazol- 4-yl)methyl]thio]ethyl] Chemical name:

4. Chemical structure:

5. Cimetidine contains an imidazole ring, and is chemically related to histamine. ( http://www.drugs.com/pro/cimetidine.html)

6. Empirical formula: C 10 H 16 N 6 S Pregnancy category: B

7. Physical properties:

8. Solubility: Springly soluble in water, but soluble in Alcohol . Melting point: 139 – 144 c Colour : White or off white crystalline powder. Odour : Unpleasant odour .

9. Cimetidine is a histamine H 2 -receptor antagonist. It reduces gastric secreation. Cimetidine inhibits many of the isoenzymes of the hepatic CYP450 enzyme system.

10. Cimetidine binds to an H 2 -receptor located on the basolateral membrane of the gastric parietal cell, blocking histamine effects. This competitive inhibition results in reduced gastric acid secretion and a reduction in gastric volume and acidity.

11. Pharmacokinetics

12. Metabolism: Liver, inhibit microsomal enzymes Metabolites: Cimetidine sulfoxide, 5-hydroxymethyl derivative (inactive met) (lynn wecker page # 198) Bioavailability: PO: 60-70% (undergoes minimal 1st pass metabolism) Protein Bound: 15-20% Half life: 2 hours Absorption : Oral/I.V 60 %  

13. Excretion: Urine: 48-75% Feces: 2-3%

14. Enzymes inhibited:

15. Clinical Uses & therapeutic Indication

16. Peptic Ulcer: Peptic ulcers are sores in the lining of the stomach or duodenum. Causes : H.pylori bacteria . Regular use of pain relievers. NSAID,s ( aspirin, ibuprofen , naproxen , ketoprofen ) (This information taken from book Medical pharmacology by Padmaja Udaykumar )(page #317) )

17. Gastroesophageal reflux disease Reflux Oesophagitis : Acid from the stomach leaks up into the gullet ( oesophagus ) This information taken from ( http://www.patient.co.uk/health/Acid-Reflux-and-Oesophagitis.htm )

18. Zollinger -Ellison syndrome: The exact cause of Zollinger -Ellison syndrome remains unknown. Zollinger -Ellison syndrome are made up of cells (gastrinomas) that secrete large amounts of gastrin , which in turn causes the stomach to produce far too much acid. ( http://www.mayoclinic.com/health/zollinger-ellison-syndrome/DS00461/DSECTION=causes )

19. Acid related dyspepsia: Dyspepsia is sometimes called indigestion. Discomfort that causes persistent pain or fullness in the upper abdomen, soon after the meal starts. ( http://www.medindia.net/patients/patientinfo/indigestion.htm )

20. Stress ulcer: Stress can contribute to the development of many diseases .This includes stomach, or peptic, ulcers.   ( http://www.livestrong.com/article/174015-a-stomach-ulcer-from-stress/#ixzz2F8KFZBmc )

21. Dosages

22. This information taken from book Pharmaguid page # 38

23. These information taken from, P harmaguide page #39. http://www.merckmanuals.com/professional/clinical_pharmacology/pharmacokinetics/drug_metabolism.html http://www.aafp.org/afp/2007/0801/p391.html

24. Advers drug reactions Advers drug reactions

25. Common side effects: Headache. Constipation. Confusion. Somnolence. Rare but dangerous side effect: Decrease libido Decrease sperm count Impotence Gynecomastia (These side effects associated with high dose of cimetidine ) Lynn wecker page # 200

26. Brand names for Cimetidine

27. Any Question ?