Urinary Antiseptic Antispasmodic

INDICATION AND USAGE ME/NaPhos/MB/Hyo 1 Tablets is indicated for the treatment of symptoms of irritative voiding. Indicated for the relief of local symptoms, such as hypermotility which accompany lower urinary tract infections and as antispasmodic. Indicated for the relief of urinary tract symptoms caused by diagnostic procedures.

DOSAGE AND ADMINISTRATION Adults One tablet orally 4 times per day followed by liberal fluid intake. Older Children Dosage must be individualized by physician. Not recommended for use in children up to 6 years of age.

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

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 methylene blue.

ADVERSE REACTIONS Cardiovascula r – rapid pulse, flushing Central Nervous System – blurred vision, dizziness Respiratory – shortness of breath or troubled breathing Genitourinary – difficulty micturition, acute urinary retention Gastrointestinal – dry mouth, nausea/vomiting

CLINICAL PHARMACOLOGY HYOSCYAMINE is a parasympatholytic which relaxes smooth muscles and thus produces an antispasmodic effect. It is well absorbed from the gastrointestinal tract and is rapidly distributed throughout body tissues. Most is excreted in the urine within 12 hours, 13% to 50% being unchanged. Its biotransformation is hepatic. Its protein binding is moderate. METHENAMINE degrades in an acidic urine environment releasing formaldehyde which provides bactericidal or bacteriostatic action. It is well absorbed from the gastrointestinal tract. 70% to 90% reaches the urine unchanged at which point it is hydrolyzed if the urine is acidic. Within 24 hours it is almost completely (90%) excreted; of this amount at pH 5, approximately 20% is formaldehyde. Protein binding: some formaldehyde is bound to substances in the urine and surrounding tissues. Methenamine is freely distributed to body tissue and fluids but is not clinically significant as it does not hydrolyze at pH greater than 6.8. METHYLENE BLU E possesses weak antiseptic properties. It is well absorbed in the gastrointestinal tract and is rapidly reduced to leukomethylene blue which is stabilized in some combination form in the urine. 75% is excreted unchanged. MONOBASIC SODIUM PHOSPHATE helps to maintain an acid pH in the urine necessary for the degradation of methenamine.