Why some proton pump inhibitors are more equal than others

• Published in: Nederlands tijdschrift voor geneeskunde Vol. 153; p. B414
• Main Authors: Otten, Marten H, Lekkerkerker, J F F Frits, Mulder, Chris J J
• Format: Journal Article
• Language: Dutch
• Published: Netherlands 2009
• Subjects: 2-Pyridinylmethylsulfinylbenzimidazoles; Deglutition Disorders - etiology; Drugs, Generic - adverse effects; Drugs, Generic - pharmacokinetics; Drugs, Generic - therapeutic use; Female; Gastroesophageal Reflux - drug therapy; Humans; Intestinal Absorption; Male; Middle Aged; Omeprazole - pharmacokinetics; Omeprazole - therapeutic use; Proton Pump Inhibitors - pharmacokinetics; Proton Pump Inhibitors - therapeutic use
• ISSN: 0028-2162

After the omeprazole patent expired in 2002, numerous generic products were introduced on the market. In a relatively short time many patients received substituted treatment. Clinicians noted a substantial number of patients with more reflux symptoms. We describe a male surgeon of 61 and a woman of 59 both with the red flag symptom of dysphagia after generic substitution. The first patient received a generic substitute of omeprazole, the second a therapeutic substitute of pantoprozole, i.e. omeprazole. The literature suggests three possibilities to explain the inadequacy of the substitution: (a) biphasic metabolism where the raised pH in the stomach may prematurely inactivate the PPI, with an unpredictable effect, (b) differences in acid-resistant coating of the generic products, and (c) influence of multiple dosing of PPIs after several days' use. We conclude that all three factors may contribute to a difference in absorption and therefore clinical effectiveness.