FDA label 45c7c55c-ce7d-1f92-e054-00144ff8d46c

openFDA label record#

This page contains supplementary openFDA label data. For the canonical label presentation, use the corresponding DailyMed Structured Product Label.

Verified complete openFDA source JSON (canonical bytes are SHA-256 checked before publication)

SPL set ID
dc773b57-378b-4650-9bb0-34e6f8c067ab
SPL ID
45c7c55c-ce7d-1f92-e054-00144ff8d46c
Version
2
Effective date
2017-01-10
Source export date
2026-09-28
Source partition
13
Source file
https://download.open.fda.gov/drug/label/drug-label-0013-of-0014.json.zip
Source object key
raw/openfda/drug-label/2026-09-28/e78bf8aa9f90ab13e640d254dfbd4fe5bfeca4995ec5f9d51bce3356e249cab7/drug-label-0013-of-0014.json.zip
Source manifest SHA-256
cd2e66336a5cd2223fa3995098fdbdb84c6a7ee5c0a4addb236ccb22dd1e6887
Import run
20260929T050834Z
Imported at
2026-09-29 06:31:03

Warnings cross-check#

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Warnings sections page 1 of 1 · 1 matching rows.

warnings

WARNINGS Do not exceed recommended dosage. If rapid pulse, dizziness or blurring of vision occurs discontinue use immediately.

Adverse reactions cross-check#

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Adverse reactions sections page 1 of 1 · 1 matching rows.

adverse reactions

ADVERSE REACTIONS Cardiovascular: rapid heartbeat, flushing Central Nervous System: blurred vision, dizziness, drowsiness Genitourinary: difficult micturition, acute urinary retention Gastrointestinal: dry mouth, nausea and vomiting Respiratory: shortness of breath or trouble breathing Serious allergic reactions to this drug are rare. Seek immediate medical attention if you notice symptoms of a serious allergic reaction, including itching, rash, severe dizziness, swelling or trouble breathing. This medication can cause urine and sometimes stools to turn blue to blue-green. This effect is harmless and will subside after medication is stopped. Call your doctor or physician for medical advice about side effects. To report SUSPECTED ADVERSE REACTIONS, contact Stellar Pharmacal at 1-800-845-7827 or FDA at 1-800-FDA-1088, www.fda.gov/medwatch. 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), opioid (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 should be advised that the urine may become blue to blue-green and the feces may be discolored as a result of the excretion of the Methylene blue.

Reported adverse events (FAERS/openFDA)#

Adverse event summaries are temporarily unavailable. Other product information remains available.