Does Methenamine Sodium Phosphate Monobasic Methylene Blue And Hy Interact with Ketoconazole?
CDI records a major classification for Methenamine Sodium Phosphate Monobasic Methylene Blue And Hy and Ketoconazole. The stored summary is: Drug Interactions because of this product's effect on gastrointestinal motility and gastric emptying, it may decrease the absorption of other oral medications during concurrent use such as: urinary alkalizers; thiazide diuretics (may cause the urine to become alkaline reducing the effectiveness of methenamine by inhibiting its conversion to formaldehyde); antimuscarinics (concurrent use may intensify antimuscarinic effects of hyoscyamine because of secondary antimuscarinic activities of these medications); antacids/antidiarrheals (may reduce absorption of hyoscyamine, concurrent use with antacids may cause urine to become alkaline reducing effectiveness of methenamine by inhibiting its conversion to formaldehyde) doses of these medications should be spaced 1 hour apart from doses of hyoscyamine; antimyasthenics (concurrent use with hyoscyamine may further reduce intestinal motility); ketoconazole (patients should be advised to take this combination at least 2 hours after ketoconazole); monoamine oxidase (MAO) Inhibitors (concurrent use may intensify antimuscarinic side effects, opoid (narcotic) analgesics may result in increased risk of severe constipation); sulfonamides (these drugs may precipitate with formaldehyde in the urine, increasing the danger of crystalluria). Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This record was extracted from drug labeling through openFDA. NIH/NLM RxNorm is used for drug identities. The summary and severity classification are CDI's processed information, not a verbatim source quotation. Product, route, and patient circumstances matter.
Evidence status
A current label comparison is not yet available for this record. The summary and severity are stored CDI information; they have not been independently validated on this page against the exact product label.
Confirm the medicine, formulation, route, and applicable warning with your pharmacist or prescriber. Independent clinical review has not been recorded.
- Stored CDI classification
- Major
- Ketoconazole Class
- Azole Antifungal
- Management
- Confirm exact products with your pharmacist
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Methenamine Sodium Phosphate Monobasic Methylene Blue And Hy and your doctor is considering prescribing Ketoconazole (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask how frequently you should be monitored while these are co-prescribed
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider