Lansoprazole

Lansoprazole is used for treatment of:

• Ulcers of the stomach and duodenum, and NSAID-induced ulcers
• Helicobacter pylori infection, alongside antibiotics (adjunctive treatment), treatment to kill H. pylori causing ulcers or other problems involves using two other drugs besides lansoprazole known as "triple therapy", and involves taking twice daily for 10 or 14 days lansoprazole, amoxicillin, and clarithromycin
• Gastroesophageal reflux disease
• Zollinger-Ellison syndrome

There is no good evidence that it works better than other PPIs.

Side effects of PPIs in general and lansoprazole in particular may include:

• Common: diarrhea, abdominal pain
• Infrequent: dry mouth, insomnia, drowsiness, blurred vision, rash, pruritus
• Rarely and very rarely: taste disturbance, liver dysfunction, peripheral oedema, hypersensitivity reactions (including bronchospasm, urinary, angioedema, anaphylaxis), photosensitivity, fever, sweating, depression, interstitial nephritis, blood disorders (including leukopenia, leukocytosis, pancytopenia, thrombocytopenia), arthralgia, myalgia, skin reactions including (erythroderma, Stevens-Johnson syndrome, toxic epidermal necrolysis, bullous eruption)

PPIs may be associated with a greater risk of hip fractures and Clostridioides difficile-associated diarrhea.

Lansoprazole interacts with several other drugs, either due to its nature or as a PPI.

• PPIs reduce absorption of antifungals (itraconazole and ketoconazole) and possibly increase digoxin in plasma
• Increases plasma concentrations of cilostazol (risk of toxicity)

Lansoprazole possibly interacts with, among other drugs:

• sucralfate
• ampicillin
• bisacodyl
• clopidogrel
• delavirdine
• fluvoxamine
• iron salts
• voriconazole
• aminophylline and theophylline
• astemizole

It is a racemic 1:1 mixture of the enantiomers dexlansoprazole and levolansoprazole. Dexlansoprazole is an enantiomerically pure active ingredient of a commercial drug as a result of the enantiomeric shift. Lansoprazole's plasma elimination half-life (1.5 h) is not proportional to the duration of the drug's effects to the person (i.e., gastric acid suppression).

Lansoprazole was originally synthesized at Takeda and was given the development name AG 1749. Takeda patented it in 1984 and the drug was launched in 1991. In the United States, it was approved for medical use in 1995.

Patents

Patent protection of the lansoprazole molecule expired on 10 November 2009, and generic formulations became available under many brand names in many countries. Some formulations may not be available in generic form.

Availability

Since 2009, lansoprazole has been available over the counter (OTC) in the U.S. as Prevacid 24HR and as Lansoprazole 24HR. In Australia, it is marketed by Pfizer as Zoton.

In vitro experiments have shown that lansoprazole binds to the pathogenic form of tau protein. As of 2015 laboratory studies were underway on analogs of lansoprazole to explore their use as potential PET imaging agents for diagnosing tauopathies including Alzheimer's disease.