1. Justification for Use
- Short-term management for active duodenal ulcer.
- Long term prophylaxis
- Benign gastric ulcer
- Gastric hypersensitivity conditions
- Acid indigestion
- Soar stomach
- To prevent upper gastrointestinal bleeding in acute ill patients
2. Process/Critical indicators
I. Adverse effects
- 1-10 %
- CNS: Dizziness, drowsiness, headache.
- GIT: Nausea, vomiting, diarrhea.
- Less than 1 %
- Bradycardia, tachycardia, and hypotension.
II. Contraindications: Hypersensitivity to cimetidine
III. Precautions/Warning: Adjust the dose in renal or hepatic impairment.
IV. Toxicity
III. Precautions/Warning: Adjust the dose in renal or hepatic impairment.
IV. Toxicity
- Vomiting
- Diarrhea
- Hypotension
- Respiratory failure
- Restlessness
- The toxic dose is 20 gm.
Management:
- Gastric lavage
- Induction of vomiting
- Maintenance of supportive therapy.
V. Interactions
- Drug-drug interactions: Benzodiazepines, €-blockers, Ca-channel blockers and lidocaine increase the serum concentration of cimetidine.
- Drug-alcohol interaction: Avoid use with alcohol because alcohol causes gastric irritations.
- Drug-food interactions: Food decreases its absorption, therefore should be taken at least 30 min before meal. With coffee, it causes increased serum level of caffeine.
VI. Pharmacokinetics
- The onset of action: 1 hour
- Duration of action: 6 hours
- Protein binding: 20%
- Distribution: Can cross the placenta as well as enter breast milk.
- Metabolism: Partly hepatic
- Bioavailability: 40-60 %
- Elimination half-life :
- Neonates: 3.6 hrs
- Children: 1.4 hrs
- Adults: 2 hrs ( Ele: t⅟₂ is 1.4 hr in children because in children the rate of metabolism is high)
- Peak concentration time: 2 hrs after I.M / I.V / oral administration.
- Excretion: urine (primarily unchanged)
VII. Dose
- Children: 20-40 mg/kg/day IM/IV/Oral
- Adult: 300 mg 6 hourly IM/IV/Oral
VIII. Dosage form
As HCl salt.
- Injection: 300 mg/ml
- Suspension : 100 mg/5ml
- Tablets: 200 mg, 400 mg.
IX. Drug-lab interactions
- Raised ALT and AST
X. Monitoring test
- Complete Blood Count (CBC)
- Gastric PH
- Liver function test
XI. Patient education
- Smoking decreases the effectiveness of cimetidine.
- Avoid use of ethanol
- Inform prescriber of all prescriptions.
Conclusion
- Take 30 min before meal.
- Let your physician know about kidney or liver disease.
- If dose is skipped, then follow the routine schedule, never double the dose.
- Let your doctor know about the pregnancy.
- Should not be used in immune-compromised individual because raised gastric PH may lead to an infection strong lodiasis.
- Should not be used in child under 16 years of age.
Tags
Medical