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Transcript of cimetidine
Cimetidine
Presented By:
Ameer
Hamza
ShaheedSubmitted To:
Sir Irfan Hamid
Drug name : Cimetidin
Pharmacological class: Histamine H2 Antagonists
Enzyme Inhibitors
Therapeutic class: Anti-Ulcer Agents
Cimetidine
GUANIDINE, N-CYANO-N'-METHYL-N''-[ 2-[[(5-METHYL-1H-IMIDAZOL- 4-YL)METHYL]THIO]ETHYL]
Chemical name:
Chemical structure:
CIMETIDINE CONTAINS AN IMIDAZOLE RING, AND IS CHEMICALLY RELATED TO HISTAMINE.
(HTTP://WWW.DRUGS.COM/PRO/CIMETIDINE.HTML)
EMPIRICAL FORMULA: C10H16N6S
PREGNANCY CATEGORY: B
Physical properties:
SOLUBILITY: SPRINGLY SOLUBLE IN WATER, BUT SOLUBLE IN ALCOHOL .
MELTING POINT: 139 – 144 C
Colour: White or off white crystalline powder.
Odour: Unpleasant odour.
Pharmcodynamics
CIMETIDINE IS A HISTAMINE H2-RECEPTOR ANTAGONIST.IT REDUCES GASTRIC SECREATION.
CIMETIDINE INHIBITS MANY OF THE ISOENZYMES OF THE HEPATIC CYP450 ENZYME SYSTEM.
Cimetidine binds to an H2-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.
Pharmacokinetics
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 %
Excretion:
Urine: 48-75% Feces: 2-3%
Enzymes inhibited:
CYP1A2
CYP2D6
CYP3A4
Clinical Uses & therapeutic Indication
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))
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
)
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)
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)
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 )
Dosages
• 800 mg/D• At bed time
• 400 mg q.i.d upto 12 weeks
• 200 mg q.i.d • With meal at
bed time
• 200 mg t.d.s• With meal at
bed time
Peptic Ulcer
Reflux oesophagitis
Acid related dyspeps
ia
Zollinger-Ellison
syndrome
This information taken from book Pharmaguid page # 38
Drug Interactions
Cimetidine
These information taken from,
Pharmaguide page #39.
http://www.merckmanuals.com/professional/clinical_pharmacology/pharmacokinetics/drug_metabolism.html
http://www.aafp.org/afp/2007/0801/p391.html
Common side effects:
Headache.Constipation.Confusion.Somnolence.
Rare but dangerous side effect:Decrease libidoDecrease sperm countImpotence Gynecomastia
(These side effects associated with
high dose of cimetidine)
Lynn wecker page # 200
Brand names for Cimetidin
e
B.N: Cimet
M.N: Ferozsons
Tab.: 400 mg
B.N: Normacid
M.N: Wilson
Tab.: 400 , 800 mg
B.N: Bacimet
M.N: Davis pharma
Tab.: 200 , 400 mg
Cimetidine
Any Question ?