Buy Generic Lansoprazole (Prevacid) (Zoton) and other pharmacy medication online

Why is this drug prescribed?

Lansoprazole reduces gastric acid secretions by inhibiting the H^+/K⁺-ATPase (proton pump) of the parietal cells in the gastric mucosa, the terminal phase of acid secretion. The drug is effective in the treatment of acid-related disorders of the upper gastrointestinal tract.

A single dose of 30 mg lansoprazole inhibits stimulated acid secretion by approximately 80%. Basal acid secretion and basal and stimulated secretion volumes are affected to a lesser degree.

After repeated dosing (for 7 days) 90% inhibition of stimulated acid secretion is achieved. Despite its short elimination half-life, lansoprazole has a prolonged pharmacological action, providing effective suppression of gastric acid secretion over 24 hours.

When used in combination with the recommended antibiotics, Zoton is associated with H. pylori eradication rates of up to 90%.

What side effects may occur?

Lansoprazole is well tolerated. A low incidence of events has been reported during clinical trials in 7,867 patients treated with lansoprazole. These events, which are generally transient and self-limiting, include headache, fatigue, malaise, diarrhoea, abdominal pain, dyspepsia, nausea, vomiting, dizziness, constipation, flatulence, dry or sore mouth or throat, rash, upper respiratory tract infections, urinary tract infections, arthralgia and myalgia. Dermatological reactions include urticaria and pruritus. These generally resolve on discontinuation of drug therapy. Serious dermatological reactions are rare but there have been occasional reports of erythematous or bullous rashes including erythema multiforme. Cases of hair thinning and photosensitivity have also been reported. Other reported reactions include jaundice, hepatitis, interstitial nephritis (sometimes resulting in renal failure), anaphylaxis, wheezing, angioedema, bruising, purpura, petechiae, depression, peripheral oedema, paraesthesia, blurred vision, taste disturbances, vertigo, confusion and hallucinations. Gynaecomastia and impotence may occur with long term use. During clinical trials a small number of patients developed abnormal liver function tests (predominantly gamma-GT) while on lansoprazole, however, routine monitoring of liver function tests is not required.

Isolated cases of blood dyscrasias, such as thrombocytopenia, leucopenia, neutropenia, agranulocytosis and pancytopenia have been reported, but a definite relationship to lansoprazole therapy has not been established.

Worldwide, there has been one report of acute colitis occurring in a 52 year old male patient after treatment with 60 mg/day lansoprazole for six weeks.

As with any broad-spectrum antibiotic treatment, the risk of pseudomembranous colitis should be considered in patients using triple therapy for the eradication of H.pylori.

Special warnings about this medication

As with other anti-ulcer therapies, the possibilities of malignancy should be excluded when a gastric ulcer is suspected, since treatment with lansoprazole may alleviate the symptoms of a malignancy and possibly delay its diagnosis.

Similarly, the possibility of serious underlying disease such as malignancy should be excluded before treatment for dyspepsia commences, particularly in patients of middle age or older who have new or recently changed dyspeptic symptoms.

The granules in Zoton are enteric coated. Therefore, the capsules should be swallowed whole, and should not be crushed or chewed.

Enterochromaffin-like (ECL) cell effects

Safety concerns of long term treatment relate to hypergastrinaemia and possible ECL effects. ECL cell hyperplasia and gastric carcinoid tumour were observed in animal studies (see PRECAUTIONS).

Human gastric biopsy specimens from patients treated with proton pump inhibitors have not detected ECL cell effects similar to those seen in rats. Gastric biopsies taken in all the long-term maintenance studies have revealed:

• a slight increase in mean endocrine cell count during 12 months maintenance treatment with lansoprazole 15 or 30 mg, observed in 3 of 4 studies. Cell density averages were slightly higher under 30 mg lansoprazole than under 15 mg lansoprazole once daily. These observations were reversible approximately 3 months after maintenance therapy stopped in two of the studies.
• single cases of changes from normal to simple hyperplasia which persisted in one patient 3 months after discontinuation of treatment.
• for antral biopsies a greater mean gastrin-positive cell density and mean serotonin-positive cell density was found for lansoprazole 30 mg compared to lansoprazole 15 mg once daily.
• no evidence of carcinoid tumours or visible endocrine cell proliferation was seen in any patient for either fundus or antral biopsies.

Possible food and drug interactions when taking this medication

Lansoprazole is metabolised in the liver and is a weak inducer of cytochrome P450. Therefore, there is the possibility of interaction with other drugs metabolised via this system. e.g. theophylline, phenytoin, carbamazepine and warfarin. Patients receiving such drugs concomitantly with lansoprazole should be monitored to determine if any dosage adjustment is necessary.

No clinically significant effects on plasma levels of warfarin, phenytoin (single IV doses only) and diazepam have been found.

The possibility of interaction between lansoprazole and low dose oral contraceptives cannot be excluded.

There is no evidence of an interaction between lansoprazole and non-steroidal anti-inflammatory drugs or antacids.

Coadministration of lansoprazole with sucralfate delayed absorption and reduced lansoprazole bioavailability by approximately 30%. Similarly, antacids may also reduce the bioavailability of lansoprazole. Therefore, lansoprazole should be taken at least an hour prior to sucralfate or antacid administration.

Lansoprazole causes a profound and long lasting inhibition of gastric acid secretion; therefore, it is theoretically possible that lansoprazole may interfere with the absorption of drugs where gastric pH is an important determinant of bioavailability (e.g. ketoconazole, ampicillin esters, iron salts, digoxin).

Special information if you are pregnant or breastfeeding

Pregnancy Category B3

Lansoprazole has been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human foetus having been observed.

Reproductive studies conducted in pregnant rats and rabbits at oral doses up to 300 and 30 mg/kg/day, respectively, did not disclose any evidence of a teratogenic effect. A significant increase in foetal mortality was observed in the rabbit study at doses above 10 mg/kg/day. In rats a slight reduction in litter survival and weights was noted at doses above 100 mg/kg/day.

Animal studies indicate that lansoprazole is secreted into breast milk. There is no information on the secretion of lansoprazole into breast milk in humans. The use of lansoprazole during breast feeding should be avoided.

Recommended dosage

Zoton is available as 30 mg capsules.

To achieve the optimal acid inhibitory effect, and hence most rapid healing and symptom relief, Zoton should be taken in the morning before food. The capsules should be swallowed whole. Do not crush or chew (see WARNING).

Reflux oesophagitis: 30 mg lansoprazole once daily for 4 weeks. The majority of patients will be healed after the first course. For patients who have not fully healed within this time, a further 4 weeks treatment using the same dosage regimen is indicated. For long-term management, a maintenance dose of 15 mg or 30 mg once daily can be used dependent upon patient response.

Duodenal ulcer: 30 mg lansoprazole once daily for 4 weeks. For the prevention of relapse, the recommended maintenance dose is 15 mg once daily.

Gastric ulcer: 30 mg lansoprazole once daily for 8 weeks.

Eradication of H. pylori: Eradication of the infection is the single most important therapeutic intervention in patients with H. pylori positive peptic ulcer disease. The following combinations have been shown to be effective when used for 7 days:

Lansoprazole 30 mg twice daily plus two of the following antibiotics: amoxycillin 1 g twice daily, metronidazole 400 mg twice daily and clarithromycin 250 mg twice daily.

Long-term management: Zoton should only be used in certain situations including:

• in patients who have recurrent peptic ulceration where the pathogenesis of the ulcer is not related to H pylori infection; or
• where repeated eradication therapy is unsuccessful; or
• patients who have a past history of perforation or bleeding from an ulcer.

Impaired hepatic and renal functions

Lansoprazole is metabolised substantially by the liver. The results of clinical trials in patients with liver disease indicate that the metabolism of lansoprazole is prolonged in patients with severe hepatic impairment. However, no dose adjustment is necessary in these patients, although the daily dose should not exceed 30 mg.

There is no need to alter the dosage in patients with impaired renal function.

Use in elderly and children

Dosage adjustment is not required in the elderly.

There is no experience with the use of lansoprazole in children.

Overdosage

There is no information on the effect of acute overdosage. In case of overdose, supportive and symptomatic therapy should be initiated.

Doses of up to 180 mg/day for more than a year have been used to treat Zollinger Ellison Syndrome with no serious adverse effects.