Drug Interactions between celecoxib / tramadol and polyethylene glycol 3350 with electrolytes

MONITOR: The risk of seizures induced by the use of bowel cleansing preparations may be increased in patients on concomitant medications that can lower the seizure threshold, including psychotherapeutic agents (antidepressants; neuroleptics; lithium), fluoroquinolones, some antimalarial agents (chloroquine; hydroxychloroquine; mefloquine), and some narcotic analgesics. Rare cases of generalized tonic-clonic seizures and/or loss of consciousness in association with low serum osmolality and electrolyte abnormalities (e.g., hyponatremia, hypokalemia, hypocalcemia, hypomagnesemia) have been reported with the use of bowel cleansing products in patients with no prior history of seizures. The condition resolved with correction of fluid and electrolyte abnormalities.

MONITOR: The use of bowel cleansing preparations may increase the risk of ventricular arrhythmia, particularly torsade de pointes, in patients treated with drugs that can prolong the QT interval, including psychotherapeutic agents (antidepressants; neuroleptics; lithium), fluoroquinolones, some antimalarial agents (chloroquine; mefloquine; halofantrine; lumefantrine), and some narcotic analgesics (methadone; propoxyphene). Severe and potentially fatal cases of electrolyte disorders and arrhythmias have been reported in elderly patients using bowel cleansing products. Electrolyte disturbances such as hypokalemia and hypomagnesemia are known risk factors for torsade de pointes associated with QT interval prolongation.

MANAGEMENT: Caution is advised when bowel cleansing preparations are prescribed in patients treated with agents that can lower the seizure threshold and/or prolong the QT interval. Bowel cleansing preparations should not be used if these patients have impaired renal function or perfusion, dehydration, or uncorrected electrolyte abnormalities. Baseline and postprocedure labs including serum electrolytes, phosphate, BUN, and creatinine should be considered, particularly in the elderly. Patients should be advised not to exceed the recommended dosage of their bowel cleansing preparation and to drink sufficient quantities of clear fluids before, during, and after the bowel preparation process. Administration of an electrolyte rehydration solution may help attenuate the electrolyte abnormalities and hypovolemia. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.

MONITOR: Coadministration with agents that affect renal function or perfusion such as diuretics, ACE inhibitors, angiotensin receptor blockers, and nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the risk and/or severity of fluid and electrolyte disturbances associated with the use of bowel cleansing preparations. Fluid and electrolyte disturbances can lead to serious adverse events including cardiac arrhythmias, seizures, and renal impairment.

MANAGEMENT: Caution is advised when bowel cleansing preparations are used in patients treated with agents that affect renal function or perfusion, particularly if they are frail or elderly or have preexisting renal impairment. Baseline and postprocedure labs including serum electrolytes, BUN, and creatinine should be considered. Patients should be advised to drink sufficient quantities of clear fluids before, during, and after bowel cleansing. Hospitalization and intravenous fluid hydration may be appropriate for frail or elderly patients who may be unable to drink an adequate volume of fluid.

MONITOR: Coadministration with celecoxib may increase the plasma concentrations of drugs that are substrates of the CYP450 2D6 isoenzyme. The mechanism is decreased clearance due to inhibition of CYP450 2D6 activity by celecoxib.

MANAGEMENT: Caution is advised if celecoxib must be used concurrently with medications that undergo metabolism by CYP450 2D6, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever celecoxib is added to or withdrawn from therapy.