Ure-Na

The following drug interaction information is available for URE-NA (urea):

Contraindicated
Severe
Moderate

There are 0 contraindications.

There are 1 severe interactions. These drug interactions can produce serious consequences in most patients. Actions required for severe interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration scheduling, and providing additional patient monitoring. Review the full interaction monograph for more information.

Drug Interaction	Drug Names
Sodium Phosphate Bowel Cleanser/Diuretics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Bowel cleansing with sodium phosphate causes dehydration, decreased intravascular volume and hyperphosphatemia, which increases phosphate levels in the renal tubules. Abnormally high levels of calcium and phosphate in the renal tubules may precipitate out, resulting in renal injury.(1) CLINICAL EFFECTS: Use of sodium phosphate for bowel cleansing in patients maintained on diuretics may increase the risk of acute phosphate nephropathy, which is an acute kidney injury associated with deposits of calcium phosphate crystal in the renal tubules that may result in permanent renal function impairment. Acute phosphate nephropathy presents as acute kidney injury with minimal proteinuria and a bland urine sediment.(2) Use of oral sodium phosphate products at laxative doses has not been associated with acute kidney injury.(3) PREDISPOSING FACTORS: Patients who may be at an increased risk of acute phosphate nephropathy include those who are over age 55; are hypovolemic or have decreased intravascular volume; have baseline kidney disease, bowel obstruction, or active colitis; and who are using medications that affect renal perfusion or function (such as diuretics, angiotensin converting enzyme (ACE) inhibitors, angiotension receptor blockers (ARBs) and possibly nonsteroidal anti-inflammatory drugs (NSAIDs).(2) PATIENT MANAGEMENT: If possible, use an alternative agent for bowel cleansing.(1) Use sodium phosphate products with caution in patients taking medications that affect kidney function or perfusion, such as diuretics. Obtain baseline and post-procedure labs (electrolytes, calcium, phosphate, BUN, creatinine, and [in smaller, frail individuals] glomerular filtration rate). Instruct patients to drink sufficient quantities of clear fluids before, during, and after bowel cleansing and to avoid other laxatives that contain sodium phosphate. Consider hospitalization and intravenous hydration during bowel cleansing to support frail patients who may be unable to drink an appropriate volume of fluid or who may be without assistance at home.(2) Use of an electrolyte solution for rehydration may decrease the risk of acute phosphate nephropathy.(4,5) DISCUSSION: Since May 2006, the FDA has received 20 reports of acute phosphate nephropathy associated with the use of Osmo Prep. Concomitant medications included ACE inhibitors or ARBs (11), diuretics (6), and NSAIDs (4).(2) In a retrospective review of colonoscopy patients, simultaneous use of ACE inhibitors or ARBs significantly increased the risk of acute kidney injury from oral sodium phosphate. Diuretic use was also a risk factor.(6) In a case series study of 21 cases of acute phosphate nephropathy in patients who had used oral sodium phosphate, 14 patients received an ACE inhibitor or ARB, 4 used a diuretic, and 3 used an NSAID.(7) Cases have also been reported with rectal products.(8)	MB CAPS, SODIUM PHOSPHATE DIBASIC, URIMAR-T, URNEVA

Drug Interaction

Drug Names

Sodium Phosphate Bowel Cleanser/Diuretics

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Bowel cleansing with sodium phosphate causes dehydration, decreased intravascular volume and hyperphosphatemia, which increases phosphate levels in the renal tubules. Abnormally high levels of calcium and phosphate in the renal tubules may precipitate out, resulting in renal injury.(1)

CLINICAL EFFECTS: Use of sodium phosphate for bowel cleansing in patients maintained on diuretics may increase the risk of acute phosphate nephropathy, which is an acute kidney injury associated with deposits of calcium phosphate crystal in the renal tubules that may result in permanent renal function impairment. Acute phosphate nephropathy presents as acute kidney injury with minimal proteinuria and a bland urine sediment.(2) Use of oral sodium phosphate products at laxative doses has not been associated with acute kidney injury.(3)

PREDISPOSING FACTORS: Patients who may be at an increased risk of acute phosphate nephropathy include those who are over age 55; are hypovolemic or have decreased intravascular volume; have baseline kidney disease, bowel obstruction, or active colitis; and who are using medications that affect renal perfusion or function (such as diuretics, angiotensin converting enzyme (ACE) inhibitors, angiotension receptor blockers (ARBs) and possibly nonsteroidal anti-inflammatory drugs (NSAIDs).(2)

PATIENT MANAGEMENT: If possible, use an alternative agent for bowel cleansing.(1) Use sodium phosphate products with caution in patients taking medications that affect kidney function or perfusion, such as diuretics. Obtain baseline and post-procedure labs (electrolytes, calcium, phosphate, BUN, creatinine, and [in smaller, frail individuals] glomerular filtration rate).

Instruct patients to drink sufficient quantities of clear fluids before, during, and after bowel cleansing and to avoid other laxatives that contain sodium phosphate. Consider hospitalization and intravenous hydration during bowel cleansing to support frail patients who may be unable to drink an appropriate volume of fluid or who may be without assistance at home.(2) Use of an electrolyte solution for rehydration may decrease the risk of acute phosphate nephropathy.(4,5)

DISCUSSION: Since May 2006, the FDA has received 20 reports of acute phosphate nephropathy associated with the use of Osmo Prep. Concomitant medications included ACE inhibitors or ARBs (11), diuretics (6), and NSAIDs (4).(2) In a retrospective review of colonoscopy patients, simultaneous use of ACE inhibitors or ARBs significantly increased the risk of acute kidney injury from oral sodium phosphate.

Diuretic use was also a risk factor.(6) In a case series study of 21 cases of acute phosphate nephropathy in patients who had used oral sodium phosphate, 14 patients received an ACE inhibitor or ARB, 4 used a diuretic, and 3 used an NSAID.(7) Cases have also been reported with rectal products.(8)

MB CAPS, SODIUM PHOSPHATE DIBASIC, URIMAR-T, URNEVA

There are 2 moderate interactions. The clinician should assess the patient’s characteristics and take action as needed. Actions required for moderate interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration.

Drug Interaction	Drug Names
Tobramycin Inhalation/Selected Diuretics SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: The combination may have additive or synergistic risks for ototoxicity and/or nephrotoxicity.(1,2) CLINICAL EFFECTS: Concurrent use may result in an increased risk of aminoglycoside toxicity.(1) PREDISPOSING FACTORS: Severe renal impairment, sepsis, or concomitant use of additional ototoxic or nephrotoxic agents may further increase the risk for toxicity. Patients carrying certain variants in the MT-RNR1 gene (m.1555A>G, m.1095T>C, and m.1494C>T) are at greatly increased risk of developing ototoxicity. An additional risk factor includes patients with a maternal relative known to have a clinically relevant MT-RNR1 variant. The risk of ototoxicity can occur at standard recommended doses of aminoglycosides.(3) PATIENT MANAGEMENT: Instruct patients to contact their provider for new onset or worsening tinnitus. Tinnitus may be a sentinel symptom of ototoxicity. In clinical trials of tobramycin inhalation 8 patients (3%) receiving tobramycin reported tinnitus while no patients in the placebo group reported this symptom.(1) For renally impaired patients receiving long term tobramycin inhalation therapy, consider measurement of serum tobramycin to assure low systemic levels. The manufacturer of tobramycin for inhalation states that the product should not be administered concurrently with ethacrynic acid, furosemide, intravenous mannitol, or urea.(1) DISCUSSION: Although systemic absorption of inhaled tobramycin is limited, the manufacturer states that because these diuretics may enhance the risk for aminoglycoside toxicity, they should not be administered concurrently with inhaled tobramycin.(1)	BETHKIS, KITABIS PAK, TOBI, TOBI PODHALER, TOBRAMYCIN
Zoledronic Acid/Diuretics SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of zoledronic acid and a diuretic may have adverse effects on the renal system.(1,2) CLINICAL EFFECTS: Concurrent use of zoledronic acid and a diuretic may result in renal dysfunction. Deterioration in renal function, acute renal failure requiring dialysis, and death have been reported.(1) PREDISPOSING FACTORS: The interaction may be more likely in elderly patients, patients who are taking other drugs that impact renal function, patients with pre-existing renal compromise, and patients who are dehydrated.(1) PATIENT MANAGEMENT: Patients should be adequately hydrated with 500 ml (2 glasses of water) before and after zoledronic acid administration.(1) Creatinine clearance should be monitored before and after therapy and zoledronic acid should not be administered in patients with a creatinine clearance less than 35 ml/min.(1,3) DISCUSSION: Zoledronic acid has been associated with renal dysfunction, including deterioration in renal function, acute renal failure requiring dialysis, and death. Risk factors include advanced age, concomitant nephrotoxic agents, and dehydration.(1) The FDA has received 16 reports of fatal acute renal failure and 9 reports of renal injury requiring dialysis following the administration of Reclast (zoledronic acid).(3)	RECLAST, ZOLEDRONIC ACID

Drug Interaction

Drug Names

Tobramycin Inhalation/Selected Diuretics

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The combination may have additive or synergistic risks for ototoxicity and/or nephrotoxicity.(1,2)

CLINICAL EFFECTS: Concurrent use may result in an increased risk of aminoglycoside toxicity.(1)

PREDISPOSING FACTORS: Severe renal impairment, sepsis, or concomitant use of additional ototoxic or nephrotoxic agents may further increase the risk for toxicity. Patients carrying certain variants in the MT-RNR1 gene (m.1555A>G, m.1095T>C, and m.1494C>T) are at greatly increased risk of developing ototoxicity. An additional risk factor includes patients with a maternal relative known to have a clinically relevant MT-RNR1 variant. The risk of ototoxicity can occur at standard recommended doses of aminoglycosides.(3)

PATIENT MANAGEMENT: Instruct patients to contact their provider for new onset or worsening tinnitus. Tinnitus may be a sentinel symptom of ototoxicity. In clinical trials of tobramycin inhalation 8 patients (3%) receiving tobramycin reported tinnitus while no patients in the placebo group reported this symptom.(1)

For renally impaired patients receiving long term tobramycin inhalation therapy, consider measurement of serum tobramycin to assure low systemic levels. The manufacturer of tobramycin for inhalation states that the product should not be administered concurrently with ethacrynic acid, furosemide, intravenous mannitol, or urea.(1)

DISCUSSION: Although systemic absorption of inhaled tobramycin is limited, the manufacturer states that because these diuretics may enhance the risk for aminoglycoside toxicity, they should not be administered concurrently with inhaled tobramycin.(1)

BETHKIS, KITABIS PAK, TOBI, TOBI PODHALER, TOBRAMYCIN

Zoledronic Acid/Diuretics

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Concurrent use of zoledronic acid and a diuretic may have adverse effects on the renal system.(1,2)

CLINICAL EFFECTS: Concurrent use of zoledronic acid and a diuretic may result in renal dysfunction. Deterioration in renal function, acute renal failure requiring dialysis, and death have been reported.(1)

PREDISPOSING FACTORS: The interaction may be more likely in elderly patients, patients who are taking other drugs that impact renal function, patients with pre-existing renal compromise, and patients who are dehydrated.(1)

PATIENT MANAGEMENT: Patients should be adequately hydrated with 500 ml (2 glasses of water) before and after zoledronic acid administration.(1) Creatinine clearance should be monitored before and after therapy and zoledronic acid should not be administered in patients with a creatinine clearance less than 35 ml/min.(1,3)

DISCUSSION: Zoledronic acid has been associated with renal dysfunction, including deterioration in renal function, acute renal failure requiring dialysis, and death. Risk factors include advanced age, concomitant nephrotoxic agents, and dehydration.(1) The FDA has received 16 reports of fatal acute renal failure and 9 reports of renal injury requiring dialysis following the administration of Reclast (zoledronic acid).(3)

RECLAST, ZOLEDRONIC ACID