Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.
Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
DRUG CLASS AND MECHANISM: Cimetidine belongs to a class of medications called
histamine H2-antagonists. Histamine is a natural chemical that stimulates
stomach cells to produce acid. Histamine H2-antagonists inhibit the action of
histamine on the acid-producing cells of the stomach and reduce stomach acid.
Cimetidine was approved by the FDA in 1977.
STORAGE: Store at room temperature 15-30°C (59-86°F).
PRESCRIBED FOR: Cimetidine is used for the treatment of duodenal ulcers,
active gastric ulcers, gastroesophageal reflux disease (GERD), pathological
hypersecretory conditions (e.g., Zollinger Ellison syndrome), heartburn and the
prevention of gastrointestinal bleeding.
DOSING:
Duodenal ulcers are treated with 800 mg at bedtime, 300 mg 4 times a
day at meal times and bedtime, or 400 mg twice a day for 4-6 weeks. Maintenance
therapy is 400 mg at bedtime.
Active gastric ulcers are treated with 800 mg at
bedtime or 300 mg 4 times a day at meal times and bedtime for up to 8 weeks.
The
regimen for GERD is 800 mg twice a day or 400 mg 4 times a day for 12 weeks.
Pathological hypersecretory conditions are treated with 300 mg 4 times daily up
to 2400 mg daily.
Heartburn, indigestion and sour stomach may be treated with
200 mg once or twice daily and may be administered up to 30 minutes before
ingestion of food or beverages that may cause heart burn.
For hospitalized
patients who cannot take oral medications, 300 mg of cimetidine may be
administered by intravenous or intramuscular injection every 6-8 hours. A
continuous intravenous infusion of 37.5 to 50 mg/hour also may be used.
DRUG INTERACTIONS: Cimetidine may increase the blood levels of several drugs
by reducing their elimination by the liver. This interaction may occur between
cimetidine and warfarin (Coumadin), a commonly used blood thinning agent.
Patients taking both medications should have frequent blood monitoring to avoid
accumulation of high levels of warfarin leading to excessive blood thinning and
bleeding. Cimetidine also may increase the blood levels phenytoin, theophylline,
lidocaine, amiodarone, metronidazole, loratadine, calcium channel blockers
(e.g., diltiazem, felodipine, nifedipine), bupropion, carbamazepine and
fluvastatin. Because cimetidine reduces stomach acid, it may reduce the
absorption of drugs (e.g., ketoconazole) that are best absorbed in acidic
conditions. Such drugs should be administered at least 2 hours before the
administration of cimetidine.
PREGNANCY: There are no adequate studies of cimetidine in pregnant women.
NURSING MOTHERS: Cimetidine is excreted in breast milk.
SIDE EFFECTS: Side effects due to cimetidine are rare and generally
reversible once the medication is stopped. Minor side effects include
constipation, diarrhea, fatigue, headache, insomnia, muscle pain, nausea, and
vomiting. Major side effects include confusion and hallucinations (usually in
elderly or critically ill patients); enlargement of the breasts; impotence
(usually seen in patients on high doses for prolonged periods); decreased white
blood cell counts. Other side effects include irregular heartbeat, impotence,
rash, visual changes, allergic reactions, and hepatitis.
GERD (gastroesophageal reflux disease) is a condition in which the acidified liquid
contents of the stomach backs up into the esophagus. The symptoms of uncomplicated GERD are heartburn,
regurgitation, and nausea. Effective treatment is available for most patients with GERD.
Hives, also called urticaria, is a raised, itchy area of skin that is usually a sign of an
allergic reaction. The allergy may be to food or medications, but usually the
cause of the allergy (the allergen) is unknown.
A peptic ulcer is an ulcer in the lining of the stomach, duodenum, or esophagus. Ulcer formation is related to Helicobacter pylori bacteria in the stomach, use of anti-inflammatory medications, and cigarette smoking.
Barrett's esophagus occurs as a complication of chronic gastroesophageal reflux disease (GERD), primarily in white males. GERD refers to the reflux of acidic fluid from the stomach into the esophagus (the swallowing tube), and is classically associated with heartburn.
Molluscum contagiosum is a skin infection caused by the poxvirus. Molluscum contagiosum appears as small tan or pink bumps on any part of the skin. Symptoms include a red or flushed appearance of the infected skin. Treatment may involve cryotherapy, manual extraction, surgical removal, the use of Retin-A, or the application of chemical acid.
Heartburn is a burning sensation experienced from acid reflux (GERD). Symptoms of heartburn include chest pain, burning in the throat, difficulty swallowing, the feeling of food sticking in the throat, and a burning feeling in the chest. Causes of heartburn include dietary habits, lifestyle habits, and medical causes. Treatments for heartburn include lifestyle changes, OTC medication, prescription medication, and surgery.
Acid backing up into the larynx (voice box), it causes reflux laryngitis. Irritation of the lining of the esophagus, larynx, and throat can lead to esophagitis, sinusitis, strictures, hoarseness, throat clearing, swallowing problems, asthma, chronic cough, and more. Typical symptoms of reflux laryngitis include heartburn, hoarseness, or a sensation of a foreign body in the throat. Reflux laryngitis can be treated with OTC medication, prescription medication, and lifestyle changes.
Barrett's esophagus is a
complication of chronic gastroesophageal reflux disease (GERD), primarily in
white men. GERD is a disease in which there is reflux of acidic fluid from the
stomach into the esophagus (the swallowing tube). It most commonly causes heartburn.
There
are two requirements for the diagnosis of Barrett's esophagus. The requirements necessitate an endoscopy of the esophagus. During endoscopy, a long flexible tube with a light and camera at its tip (an endoscope) is inserted
through the mouth and into the esophagus to view and biopsy (sample tissue from) the lining of the esophagus. The two requirements are:
At endoscopy, an abnormal pink lining should be seen as replacing the normal whitish lining of the esophagus. This abnormal lining extends a short distance (usually less than 2.5 inches) up the esophagus from the gastroesophageal junction (the GE junction, which is where the e...