Actions of Omekan in details
Pharmacology: Mechanism of Action: Omekan is a specific inhibitor of a gastric proton pump in the parietal cell and thus, reduces the secretion of gastric acid. Reversible control of gastric acid secretion is produced with a single daily doses of Omekan. Omekan is a weak base, which is concentrated in the intracellular canaliculi of the parietal cell. Due to acidic environment in these cells, Omekan is converted to the active form, where it acts as an inhibitor of the enzyme H+, K+ -ATPase the proton pump. There is a dose dependency on this final step in the formation of gastric acid, which provides for effective inhibition of the secretion of both basal acid stimulated acid irrespective of the secretory enhancer. When Omekan is given daily as a single oral dose, the gastric acid secretion is inhibited with a maximum effect reached within 4 days of treatment in patients with duodenal ulcers, a mean decrease of approximately 80% in intragastric acidity is then maintained over a 24-hr period, with the mean decrease in peak acid output after pentagastrin stimulation being approximately 70%, 24 hrs after initiating treatment with Omekan.
Pharmacokinetics: Due to the acid lability of Omekan, the oral formulation consists of enteric-coated granules in capsules. Omekan is usually completely absorbed from the small intestine within 3-6 hrs. After a single oral dose, the systemic bioavailability of Omekan is approximately 35% which can be increased to about 60% after a repeated once-daily administration.
The simultaneous intake of food has no influence on the bioavailability. Omekan is approximately 95% bound to plasma proteins. The average terminal phase t½ of the plasma concentration-time curve is approximately 40 min. There is no change in t½ during treatment. The inhibition of acid secretion is related to the AUC and not to the actual plasma concentration at a given time.
Omekan is completely metabolized mainly in the liver. The sulfone and hydroxyl Omekan are metabolites detected in plasma. These metabolites are inactive and have no significant effect on acid secretion. Approximately 80% of the metabolites are excreted in the urine and the balance in the feces. The 2 main metabolites in the urine are hydroxy-Omekan and the corresponding carboxylic acid.
There is no significant change in the systemic bioavailability of Omekan in patients with impaired renal function. Although the AUC is increased in patients with reduced liver function, no apparent accumulation of Omekan has been found.
How should I take Omekan?
Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.
Use Omekan OTC (over-the-counter) exactly as directed on the label, or as prescribed by your doctor.
Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.
Shake the oral suspension (liquid) before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).
If you cannot swallow a capsule whole, open it and sprinkle the medicine into a spoonful of applesauce. Swallow the mixture right away without chewing. Do not save it for later use.
You must dissolve Omekan + SyrSpend SF Alka powder in a small amount of water. This mixture can either be swallowed or given through a nasogastric (NG) feeding tube using a catheter-tipped syringe.
OTC Omekan + SyrSpend SF Alka should be taken for only 14 days in a row. Allow at least 4 months to pass before you start a new 14-day course of treatment.
Use this medicine for the full prescribed length of time, even if your symptoms quickly improve.
Call your doctor if your symptoms do not improve, or if they get worse.
Some conditions are treated with a combination of Omekan + SyrSpend SF Alka and antibiotics. Use all medications as directed.
This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using Omekan + SyrSpend SF Alka.
Store at room temperature away from moisture and heat.
Omekan administration
Omekan is usually taken before eating. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Omekan OTC (over-the-counter) should be taken only once every 24 hours for 14 days. Take the medicine in the morning before you eat breakfast. It may take up to 4 days for full effect. Do not take more than one tablet every 24 hours.
Allow at least 4 months to pass before you start another 14-day treatment with Omekan OTC. Call your doctor if you have additional symptoms and need treatment before the 4 months has passed.
Do not crush, chew, or break an enteric coated pill, or a Omekan OTC tablet. Swallow the pill whole.
You may open the delayed-release capsule and sprinkle the medicine into a spoonful of applesauce to make swallowing easier. Swallow the mixture right away without chewing. Do not save for later use.
Dissolve the powder in a small amount of water. Use 1 teaspoon of water for the 2.5-mg packet, or 1 Tablespoon of water for the 10-mg packet. Let the mixture stand for 2 or 3 minutes, then stir and drink right away. To make sure you get the entire dose, add a little more water to the same glass, swirl gently and drink right away.
This mixture can also be given through a nasogastric (NG) feeding tube using only a catheter-tipped syringe. Shake the syringe well, then attach it to the NG tube and push the plunger down to empty the syringe into the tube. Refill the syringe with water and flush the tube to wash the contents down.
Use this medication for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared.
Call your doctor if your symptoms do not improve, or if they get worse while using Omekan.
Some conditions are treated with a combination of Omekan and antibiotics. Use all medications as directed by your doctor. Read the medication guide or patient instructions provided with each medication. Do not change your doses or medication schedule without your doctor's advice.
This medication can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using Omekan.
Store at room temperature away from moisture and heat.
Omekan pharmacology
Mechanism Of Action
Omekan belongs to a class of antisecretory compounds, the substituted benzimidazoles, that suppress gastric acid secretion by specific inhibition of the HDefined as complete resolution of heartburn
*(p < 0.005) versus 10 mg
†(p < 0.005) versus placebo
Erosive Esophagitis
In a U.S. multicenter double-blind placebo controlled study of 20 mg or 40 mg of Omekan Delayed-Release Capsules in patients with symptoms of GERD and endoscopically diagnosed erosive esophagitis of grade 2 or above, the percentage healing rates (per protocol) were as follows:
| Week | 20 mg Omekan (n = 83) | 40 mg Omekan (n = 87) | Placebo (n = 43) |
| 4 | 39** | 45** | 7 |
| 8 | 74** | 75** | 14 |
| ** (p < 0.01) Omekan versus placebo. |
In this study, the 40 mg dose was not superior to the 20 mg dose of Omekan in the percentage healing rate. Other controlled clinical trials have also shown that Omekan is effective in severe GERD. In comparisons with histamine H2-receptor antagonists in patients with erosive esophagitis, grade 2 or above, Omekan in a dose of 20 mg was significantly more effective than the active controls. Complete daytime and nighttime heartburn relief occurred significantly faster (p < 0.01) in patients treated with Omekan than in those taking placebo or histamine H2-receptor antagonists.
In this and five other controlled GERD studies, significantly more patients taking 20 mg Omekan (84%) reported complete relief of GERD symptoms than patients receiving placebo (12%).
Long-Term Maintenance Of Healing of Erosive Esophagitis
In a U.S. double-blind, randomized, multicenter, placebo controlled study, two dose regimens of Omekan were studied in patients with endoscopically confirmed healed esophagitis. Results to determine maintenance of healing of erosive esophagitis are shown below.
Life Table Analysis
| Omekan 20 mg once daily (n = 138) | Omekan 20 mg 3 days per week (n = 137) | Placebo (n = 131) | |
| Percent in endoscopic remission at 6 months | * | 34 | 11 |
| *(p < 0.01) Omekan 20 mg once daily versus Omekan 20 mg 3 consecutive days per week or placebo. |
In an international multicenter double-blind study, Omekan 20 mg daily and 10 mg daily were compared with ranitidine 150 mg twice daily in patients with endoscopically confirmed healed esophagitis. The table below provides the results of this study for maintenance of healing of erosive esophagitis.
Life Table Analysis
| Omekan 20 mg once daily (n = 131) | Omekan 10 mg once daily (n = 133) | Ranitidine 150 mg twice daily (n = 128) | |
| Percent in endoscopic remission at 12 months | *77 | ‡58 | 46 |
| * (p = 0.01) Omekan 20 mg once daily versus Omekan 10 mg once daily or Ranitidine. ‡ (p = 0.03) Omekan 10 mg once daily versus Ranitidine. |
In patients who initially had grades 3 or 4 erosive esophagitis, for maintenance after healing 20 mg daily of Omekan was effective, while 10 mg did not demonstrate effectiveness.
Pathological Hypersecretory Conditions
In open studies of 136 patients with pathological hypersecretory conditions, such as Zollinger-Ellison (ZE) syndrome with or without multiple endocrine adenomas, Omekan Delayed-Release Capsules significantly inhibited gastric acid secretion and controlled associated symptoms of diarrhea, anorexia, and pain. Doses ranging from 20 mg every other day to 360 mg per day maintained basal acid secretion below 10 mEq/hr in patients without prior gastric surgery, and below 5 mEq/hr in patients with prior gastric surgery.
Initial doses were titrated to the individual patient need, and adjustments were necessary with time in some patients. Omekan was well tolerated at these high dose levels for prolonged periods ( > 5 years in some patients). In most ZE patients, serum gastrin levels were not modified by Omekan. However, in some patients serum gastrin increased to levels greater than those present prior to initiation of Omekan therapy. At least 11 patients with ZE syndrome on long-term treatment with Omekan developed gastric carcinoids. These findings are believed to be a manifestation of the underlying condition, which is known to be associated with such tumors, rather than the result of the administration of Omekan.
Pediatric GERD
Symptomatic GERD
The effectiveness of Omekan for the treatment of nonerosive GERD in pediatric patients 1 to 16 years of age is based in part on data obtained from 125 pediatric patients in two uncontrolled Phase III studies.
The first study enrolled 12 pediatric patients 1 to 2 years of age with a history of clinically diagnosed GERD. Patients were administered a single dose of Omekan (0.5 mg/kg, 1.0 mg/kg, or 1.5 mg/kg) for 8 weeks as an open capsule in 8.4% sodium bicarbonate solution. Seventy-five percent (9/12) of the patients had vomiting/regurgitation episodes decreased from baseline by at least 50%.
The second study enrolled 113 pediatric patients 2 to 16 years of age with a history of symptoms suggestive of nonerosive GERD. Patients were administered a single dose of Omekan (10 mg or 20 mg, based on body weight) for 4 weeks either as an intact capsule or as an open capsule in applesauce. Successful response was defined as no moderate or severe episodes of either pain-related symptoms or vomiting/regurgitation during the last 4 days of treatment. Results showed success rates of 60% (9/15; 10 mg Omekan) and 59% (58/98; 20 mg Omekan), respectively.
Healing of Erosive Esophagitis
In an uncontrolled, open-label dose-titration study, healing of erosive esophagitis in pediatric patients 1 to 16 years of age required doses that ranged from 0.7 to 3.5 mg/kg/day (80 mg/day). Doses were initiated at 0.7 mg/kg/day. Doses were increased in increments of 0.7 mg/kg/day (if intraesophageal pH showed a pH of < 4 for less than 6% of a 24-hour study). After titration, patients remained on treatment for 3 months. Forty-four percent of the patients were healed on a dose of 0.7 mg/kg body weight; most of the remaining patients were healed with 1.4 mg/kg after an additional 3 months' treatment. Erosive esophagitis was healed in 51 of 57 (90%) children who completed the first course of treatment in the healing phase of the study. In addition, after 3 months of treatment, 33% of the children had no overall symptoms, 57% had mild reflux symptoms, and 40% had less frequent regurgitation/vomiting.
Maintenance of Healing of Erosive Esophagitis
In an uncontrolled, open-label study of maintenance of healing of erosive esophagitis in 46 pediatric patients, 54% of patients required half the healing dose. The remaining patients increased the healing dose (0.7 to a maximum of 2.8 mg/kg/day) either for the entire maintenance period, or returned to half the dose before completion. Of the 46 patients who entered the maintenance phase, 19 (41%) had no relapse. In addition, maintenance therapy in erosive esophagitis patients resulted in 63% of patients having no overall symptoms.
REFERENCES
1. National Committee for Clinical Laboratory Standards. Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically—Fifth Edition. Approved Standard NCCLS Document M7-A5, Vol, 20, No. 2, NCCLS, Wayne, PA, January 2000.
References
- DailyMed. "OMEPRAZOLE MAGNESIUM: DailyMed provides trustworthy information about marketed drugs in the United States. DailyMed is the official provider of FDA label information (package inserts).". https://dailymed.nlm.nih.gov/dailyme... (accessed September 17, 2018).
- NCIt. "Omeprazole Magnesium: NCI Thesaurus (NCIt) provides reference terminology for many systems. It covers vocabulary for clinical care, translational and basic research, and public information and administrative activities.". https://ncit.nci.nih.gov/ncitbrowser... (accessed September 17, 2018).
- EPA DSStox. "Omeprazole: DSSTox provides a high quality public chemistry resource for supporting improved predictive toxicology.". https://comptox.epa.gov/dashboard/ds... (accessed September 17, 2018).
Reviews
The results of a survey conducted on ndrugs.com for Omekan are given in detail below. The results of the survey conducted are based on the impressions and views of the website users and consumers taking Omekan. We implore you to kindly base your medical condition or therapeutic choices on the result or test conducted by a physician or licensed medical practitioners.User reports
Consumer reported administration
No survey data has been collected yetConsumer reviews
There are no reviews yet. Be the first to write one! |
Information checked by Dr. Sachin Kumar, MD Pharmacology
