Proton pump inhibitors with itraconazole

Itraconazole has significant interactions with a number of commonly prescribed drugs, such as rifampin, phenytoin, and carbamazepine. Itraconazole raises serum digoxin and cyclosporine levels and may affect the metabolism of oral hypoglycemic agents and coumadin. Absorption of itraconazole is impaired by antacids, Hj blockers, proton pump inhibitors, and drugs that contain buffers, such as the antiretroviral agent didanosine. 

A 57-year-old man with extensive onychomycosis (fungal toenail infection) asks you for an evaluation. He requests a prescription for itraconazole for treatment of this problem after seeing a television advertisement for this drug. He has chronic heartburn attributed to gastroesophageal reflux disease and is treated with the proton pump inhibitor omeprazole. He is taking lovastatin for treatment of... 

ITRACONAZOLE, KETOCONAZOLE PROTON PUMP INHIBITORS Possible i efficacy of the antifungal L absorption Monitor for i efficacy t dose may be required. Separate doses by at least 2 hours and give ketoconazole with a cola drink... 

The interaction between itraconazole and omeprazole also appears to be established, but it appears that this can be minimised by using an oral itraconazole solution. As with ketoconazole, giving itraconazole with an acidic drink such as cola , (p.215) would minimise the interaction, and is recommended by some manufacturers of itraconazole for patients taking proton pump inhibitors. " Monitor patients taking itraconazole if proton pump inhibitors are also given. The effect of itraconazole on omeprazole is unknown, but it might be expeeted to increase omeprazole levels similarly to ketoconazole. 

An active substance, although initially released from its dosage form (and dissolved), may become unavailable for absorption due to reactimis with other medicines or food components [4]. An example is the formation of insoluble complexes of tetracycline with calcium or aluminium ions from antacids or milk products. Interaction (chelation or binding) with iron ions leads to a reduced absorption for a variety of active substances such as doxycycline, penicillamine, methyldopa and ciprofloxacin. The absorption of active substances showing pH-dependent dissolution behaviour may be influenced by medicines that influence the gastric pH, such as H2-antagonists, proton pump inhibitors and antacids. Antimycotic active substances such as ketoconazole or itraconazole dissolve better in acidic fluids. Therefore their bioavailability may be increased by the concomitant use of an acidic drink like cola, whereas the concomitant use of antacids or proton pump inhibitors is likely to reduce the bioavailability. Concomitant use of milk may increase the dissolution of acidic active substances, whereas fats from food may increase the bioavailability of lipophilic active substances like albendazole and griseofulvin. 

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