[Why some proton pump inhibitors are more equal than others].
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.
Meander Medisch Centrum, afd. Maag-, Darm- en Leverziekten, Amersfoort, The Netherlands. mh.otten@meandermc.nl
Marten H
MH
Otten
J F F Frits
JF
Lekkerkerker
Chris J J
CJ
Mulder
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D003680:Deglutition Disorders / Q000209:etiology; D016568:Drugs, Generic / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use; D005260:Female; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000493:pharmacokinetics / Q000627:therapeutic use*; D000077402:Pantoprazole; D054328:Proton Pump Inhibitors / Q000493:pharmacokinetics / Q000627:therapeutic use*
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D016568:Drugs, Generic; D054328:Proton Pump Inhibitors; D000077402:Pantoprazole; D009853:Omeprazole