Drug Interaction Report
1 drug interaction and 14 additional warnings found for the following 2 drugs:
- conivaptan
- tolterodine
Drug interactions
Moderate drug interactions
Moderate:tolterodine conivaptan
Applies to: tolterodine, conivaptan
Conivaptan may increase the blood levels and effects of tolterodine.
High levels of tolterodine can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect.
You may be more susceptible if you have:
- a heart condition called congenital long QT syndrome
- other cardiac diseases
- conduction abnormalities
- electrolyte disturbances (for example, magnesium or potassium loss due to severe or prolonged diarrhea or vomiting)
Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. Talk to your doctor if you have any questions or concerns.
You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with these medications, whether together or alone.
Contact your doctor if you experience heart palpitations, difficulty urinating, dry mouth, constipation, blurred vision, headache, drowsiness, dizziness, and/or abdominal pain.
Do not drive or operate heavy machinery until the effects of tolterodine have been determined.
It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Food/lifestyle interactions
No alcohol/food interactions were found with the drugs in your list. However, this does not necessarily mean no food interactions exist. Always consult your healthcare provider.
Disease interactions
14 potential interactionsApplies to: 11 conditions, including Heart Failure, Myasthenia Gravis, Dementia, Urinary Retention, and Liver Disease.
Alcoholism
Moderate:conivaptan
Conivaptan has a moderate potential interaction with Alcoholism.
Osmotic demyelination syndrome is a risk associated with overly rapid correction of hyponatremia (> 12 mEq/L/24 hours). This syndrome can result in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizure, coma or death. Patients with advanced liver disease, alcoholism or severe malnutrition are at increased risk and require slower rates of correction. Serum sodium concentration and neurological status should be monitored appropriately during treatment administration. Vasopressin antagonists should be initiated and re- initiated in patients only in hospital settings were sodium levels can be monitored closely.
Central Nervous System Disorders
Moderate:tolterodine
Tolterodine has a moderate potential interaction with Central Nervous System Disorders.
Tolterodine is associated with anticholinergic central nervous system (CNS) effects. If a patient experiences anticholinergic CNS effects, dose reduction or drug discontinuation should be considered. Tolterodine should be used with caution in patients with Parkinson's disease and in patients with preexisting dementia treated with cholinesterase inhibitors due to the risk of aggravation of symptoms.
Dementia
Moderate:tolterodine
Tolterodine has a moderate potential interaction with Dementia.
Tolterodine is associated with anticholinergic central nervous system (CNS) effects. If a patient experiences anticholinergic CNS effects, dose reduction or drug discontinuation should be considered. Tolterodine should be used with caution in patients with Parkinson's disease and in patients with preexisting dementia treated with cholinesterase inhibitors due to the risk of aggravation of symptoms.
Gastrointestinal Obstruction
Major:tolterodine
Tolterodine has a major potential interaction with Gastrointestinal Obstruction.
The use of tolterodine is contraindicated in patients with GI obstruction, ileus, or obstructive uropathy. Tolterodine exerts anticholinergic activity by competitive antagonism of muscarinic receptors.
Glaucoma/Intraocular Hypertension
Major:tolterodine
Tolterodine has a major potential interaction with Glaucoma/Intraocular Hypertension.
The use of tolterodine is contraindicated in patients with uncontrolled angle-closure (narrow angle) glaucoma. Tolterodine exerts anticholinergic activity and can result in increased intraocular pressure and loss of accommodation.
Heart Failure
Moderate:conivaptan
Conivaptan has a moderate potential interaction with Heart Failure.
The amount of safety data on the use of conivaptan in patients with hypervolemic hyponatremia associated with heart failure is limited. Conivaptan should only be used to raise sodium in such patients after consideration of other treatment options. Caution is advised if using in these patients.
Liver Disease
Moderate:conivaptan
Conivaptan has a moderate potential interaction with Liver Disease.
Osmotic demyelination syndrome is a risk associated with overly rapid correction of hyponatremia (> 12 mEq/L/24 hours). This syndrome can result in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizure, coma or death. Patients with advanced liver disease, alcoholism or severe malnutrition are at increased risk and require slower rates of correction. Serum sodium concentration and neurological status should be monitored appropriately during treatment administration. Vasopressin antagonists should be initiated and re- initiated in patients only in hospital settings were sodium levels can be monitored closely.
Moderate:conivaptan
Conivaptan has a moderate potential interaction with Liver Disease.
The systemic exposure to unbound conivaptan doubled in subjects with moderate and severe hepatic impairment. Caution is advised in these patients.
Moderate:tolterodine
Tolterodine has a moderate potential interaction with Liver Disease.
Tolterodine undergoes biotransformation in the liver of extensive metabolizers to an active metabolite. Poor metabolizers have a greater concentration of active parent and less active metabolite, however the net activity of tolterodine is expected to be the same. The pharmacokinetic disposition of tolterodine can be significantly altered in patients with hepatic dysfunction. Therapy with tolterodine should be administered cautiously in patients with severe hepatic impairment and dosage should be reduced to no greater than 1 mg twice daily.
Long QT Syndrome
Moderate:tolterodine
Tolterodine has a moderate potential interaction with Long QT Syndrome.
Tolterodine has been associated with QT prolongation. The effect on QT interval correlates with plasma concentration of tolterodine. Caution is recommended when prescribing this agent to patients with a known history of QT prolongation or to patients who are taking Class IA (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic medications.
Myasthenia Gravis
Moderate:tolterodine
Tolterodine has a moderate potential interaction with Myasthenia Gravis.
Tolterodine acts as a competitive antagonist of acetylcholine at postganglionic muscarinic receptors. Caution is recommended when using this agent in patients with myasthenia gravis, a disease characterized by decreased cholinergic activity at the neuromuscular junction.
Renal Dysfunction
Moderate:conivaptan
Conivaptan has a moderate potential interaction with Renal Dysfunction.
The use of conivaptan is not recommended in patients with severe renal impairment (CrCl < 30 mL/min), as there is an unlikely benefit. There is also a high incidence of infusion site phlebitis, which can reduce vascular access sites.
Moderate:tolterodine
Tolterodine has a moderate potential interaction with Renal Dysfunction.
The renal elimination of tolterodine and active metabolite is limited and a prolonged half-life is not anticipated in patients with renal impairment. However, the pharmacokinetic disposition of tolterodine has not been evaluated in patients with renal impairment and it is recommended that tolterodine be administered cautiously in patients with compromised renal function.
Urinary Retention
Major:tolterodine
Tolterodine has a major potential interaction with Urinary Retention.
The use of tolterodine is contraindicated in patients with GI obstruction, ileus, or obstructive uropathy. Tolterodine exerts anticholinergic activity by competitive antagonism of muscarinic receptors.
Drug Interaction Classification
| Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
| Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
| Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
| No interaction information available. |
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Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.