注意事项：代谢性酸中毒, 痛风, 妊娠哺乳期妇女慎用。

不良反应：恶心, 呕吐, 腹泻, 消化不良, 皮疹, 尿道特别是膀胱刺激和炎症，尿痛，尿频，蛋白尿和血尿。

药物相互作用：与尿液碱化剂、抗酸剂、枸橼酸钾及利尿剂如乙酰唑胺和噻嗪类合用，本药作用减弱。抗坏血酸或氯化铵会使尿液酸化，增加本药的作用。

严重药物相互作用：与磺胺类药合用，会导致结晶尿，避免合用。
  
与食物的相互作用：限制碱性食物的摄入。

FDA妊娠分级：C级: 动物研究证明药物对胎儿有危害性（致畸或胚胎死亡等），或尚无设对照的妊娠妇女研究，或尚未对妊娠妇女及动物进行研究。本类药物只有在权衡对孕妇的益处大于对胎儿的危害之后，方可使用。

药理作用：是一种合成的用于治疗慢性泌尿系统感染的抗菌素，抑制或预防疾病。以马尿酸盐或苯乙醇酸盐的形式存在。该药在酸性尿液中转变为甲醛发挥抗菌活性。

吸收：胃肠道容易吸收。

分布：能通过胎盘和进入乳汁。

排泄：几乎全部经尿液排泄。

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原产地英文商品名:
UTAC 100tabs/bottle
原产地英文药品名:
METHENAMINE MANDELATE/SODIUM PHOSPHATE,MONOBASIC,MONOHYDRATE
中文参考商品译名:
UTAC 100片/瓶
中文参考药品译名:
扁桃酸乌洛托品/磷酸钠,单碱,一水化物
生产厂家中文参考译名:
Breckenridge Pharmaceutical, Inc.
生产厂家英文名:
Breckenridge Pharmaceutical, Inc.

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DESCRIPTION
Each UROQID-Acid® No.2 tablet contains methenamine mandelate 500 mg and sodium acid phosphate, monohydrate 500 mg.

CLINICAL PHARMACOLOGY
Methenamine mandelate is rapidly absorbed and excreted in the urine. Formaldehyde is released by acid hydrolysis from methenamine with bactericidal levels rapidly reached at pH 5.0-5.5. Proportionally less formaldehyde is released as urinary pH approaches 6.0 and insufficient quantities are released above this level for therapeutic response. In acid urine, mandelic acid exerts its antibacterial action and also contributes to the acidification of the urine. Mandelic acid is excreted by both glomerular filtration and tubular excretion. In acid urine, there is equally effective antibacterial activity against both gram-positive and gram-negative organisms, since the antibacterial action of mandelic acid and formaldehyde is nonspecific. With Proteus vulgaris and urea splitting strains of Pseudomonas and Aerobacter, results may be discouraging and particular attention is required in monitoring urinary pH and overall management.

INDICATIONS AND USAGE
For the suppression or elimination of bacteriuria associated with chronic and recurrent infections of the urinary tract, including pyelitis, pyelonephritis, cystitis, and infected residual urine accompanying neurogenic bladder. When used as recommended, UROQID-Acid® No.2 is particularly suitable for long-term therapy because of its relative safety and because resistance to the nonspecific bactericidal action of formaldehyde does not develop. Pathogens resistant to other antibacterial agents may respond because of the nonspecific effect of formaldehyde formed in an acid urine.

Prophylactic Use Rationale:Urine is a good culture medium for many urinary pathogens. Inoculation by a few organisms (relapse or reinfection) may lead to bacteriuria in susceptible individuals. Thus, the rationale of management in recurring urinary tract infection (bacteriuria) is to change the urine from a growth-supporting to a growth-inhibiting medium. There is a growing body of evidence that long-term administration of methenamine can prevent recurrence of bacteriuria in patients with chronic pyelonephritis.

Therapeutic Use Rationale:Helps to sterilize the urine and, in some situations in which underlying pathologic conditions prevent sterilization by any means, can help to suppress bacteriuria. As part of the overall management of the urinary tract infection, a thorough diagnostic evaluation should accompany the use of this product.
CONTRAINDICATIONS
UROQID-Acid® No.2 is contraindicated in patients with renal insufficiency, severe hepatic disease, severe dehydration, hyperphosphatemia, and in patients who have exhibited hypersensitivity to any components of this product.
PRECAUTIONS
General
This product should not be used as the sole therapeutic agent in acute parenchymal infections causing systemic symptoms such as chills and fever.

UROQID-Acid® No.2 contains approximately 83 mg of sodium per tablet and should be used with caution in patients on a sodium-restricted diet.

Sodium phosphates should be used with caution in the following conditions: cardiac failure; peripheral or pulmonary edema; hypernatremia; hypertension; toxemia of pregnancy; hypoparathyroidism; and acute pancreatitis. High serum phosphate levels increase the incidence of extraskeletal calcification.

Large doses of methenamine (8 grams daily for 3 to 4 weeks) have caused bladder irritation, painful and frequent micturition, albuminuria and gross hematuria. Dysuria may occur, although usually at higher than recommended doses, and can be controlled by reducing the dosage. This product contains a urinary acidifier and can cause metabolic acidosis.

Care should be taken to maintain an acidic urinary pH (below 5.5), especially when treating infections due to urea-splitting organisms such as Proteus and strains of Pseudomonas.

Drugs and/or foods which produce an alkaline urine should be restricted. Frequent urine pH tests are essential. If acidification of the urine is contraindicated or unattainable, use of this product should be discontinued.

Information For Patients:To assure an acidic pH, patients should be instructed to restrict or avoid most fruits, milk and milk products, and antacids containing sodium carbonate or bicarbonate.

Laboratory Tests:As with all urinary tract infections, the efficacy of therapy should be monitored by repeated urine cultures. During long-term therapy, careful monitoring of renal function, serum phosphorus and sodium may be required at periodic intervals.
Drug Interactions:   Formaldehyde and sulfamethizole form an insoluble precipitate in acid urine and increase the risk of crystalluria; therefore, these products should not be used concurrently. Thiazide diuretics, carbonic anhydrase inhibitors, antacids, or urinary alkalinizing agents should not be used concurrently since they may cause the urine to become alkaline and reduce the effectiveness of methenamine by inhibiting its conversion to formaldehyde. Concurrent use of antihypertensives, especially diazoxide, guanethidine, hydralazine, methyldopa, or rauwolfia alkaloids; or corticosteroids, especially mineralocorticoids or corticotropin, with sodium phosphates may result in hypernatremia. Concurrent use of salicylates may lead to increased serum salicylate levels since excretion of salicylates is reduced in acidified urine. Serum salicylate levels should be closely monitored to avoid toxicity.

Laboratory Test Interactions:   Formaldehyde interferes with fluorometric procedures for determination of urinary catecholamines and vanilmandelic acid (VMA) causing erroneously high results. Formaldehyde also causes falsely decreased urine estriol levels by reacting with estriol when acid hydrolysis techniques are used; estriol determinations which use enzymatic hydrolysis are unaffected by formaldehyde. Formaldehyde causes falsely elevated 17-hydroxycorticosteroid levels when the Porter-Silber method is used and falsely decreased 5-hydroxyindoleacetic acid (5HIAA) levels by inhibiting color development when nitrosonaphthol methods are used.

Carcinogenesis, Mutagenesis, Impairment Of Fertility: Long-term animal studies to evaluate the carcinogenic, mutagenic, or impairment of fertility potential of this product have not been performed.

Pregnancy:Teratogenic Effects. Pregnancy Category C. Animal reproduction studies have not been conducted with UROQID-Acid® No.2. It is also not known whether this product can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. Since methenamine is known to cross the placental barrier, this product should be given to a pregnant woman only if clearly needed.

Nursing Mothers:Methenamine is excreted in breast milk. Caution should be exercised when this product is administered to a nursing woman.

ADVERSE REACTIONS
Gastrointestinal disturbances (nausea, stomach upset), generalized skin rash, dysuria, painful or difficult urination may occur occasionally with the use of methenamine preparations. Microscopic and rarely, gross hematuria have also been reported.

Gastrointestinal upset (diarrhea, nausea, stomach pain, and vomiting) may occur with the use of sodium phosphates. Also, bone or joint pain (possible phosphate induced osteomalacia) could occur. The following adverse effects may be observed (primarily from sodium): headaches; dizziness; mental confusion; seizures; weakness or heaviness of legs; unusual tiredness or weakness; muscle cramps; numbness, tingling, pain, or weakness of hands or feet; numbness or tingling around lips; fast or irregular heartbeat; shortness of breath or troubled breathing; swelling of feet or lower legs; unusual weight gain; low urine output, unusual thirst.

DOSAGE AND ADMINISTRATION
UROQID-Acid® No.2:   Adults:   Initially, 2 tablets 4 times daily with a full glass of water. For maintenance, 2 to 4 tablets daily, in divided doses with a full glass of water.

HOW SUPPLIED
UROQID-Acid® No.2 is a yellow, film-coated, capsule-shaped tablet with the name BEACH and the number 1114 imprinted on each tablet. Packaged in bottles of 100 tablets (NDC 0486-1114-01).