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Interactions between Mayzent and Uracil mustard

1 drug interaction and 16 additional warnings found for the following 2 drugs:

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Drug interactions

Major drug interactions

Major:

uracil mustard siponimod

Applies to: uracil mustard and Mayzent (siponimod)
Monitor closely

Coadministration of siponimod with antineoplastic, immunosuppressive, or other immune-modulating therapies may result in additive immune system effects and increased risk of infections. Siponimod causes reversible sequestration of lymphocytes in lymphoid tissues. When administered daily, siponimod produces a dose-dependent reduction in peripheral lymphocyte count to 20% to 30% of baseline values, which may increase the risk of infections. Life-threatening and rare fatal infections have occurred in association with siponimod. Decreased lymphocyte counts persist during chronic daily dosing and generally return to normal within 10 days after stopping the medication. However, residual pharmacodynamic effects, such as decreased peripheral lymphocytes, may persist for up to 3 to 4 weeks after the last dose. Use of other myelo- or immunosuppressive drugs during this time may lead to unintended additive effects on the immune system.

Management

The safety and efficacy of siponimod in combination with antineoplastic, immunosuppressive, or other immune-modulating agents have not been evaluated. Close monitoring for signs and symptoms of infection is advised during coadministration and for 3 to 4 weeks after the last dose of siponimod. When switching from drugs with prolonged immune effects to siponimod, the half-life and mode of action of these drugs must be considered to avoid unintended additive immunosuppressive effects while at the same time minimizing risk of disease reactivation.

References (3)
  1. (2022) "Product Information. Mayzent (siponimod)." Novartis Pharmaceuticals
  2. (2025) "Product Information. Mayzent (siponimod)." Novartis Pharmaceuticals UK Ltd
  3. (2025) "Product Information. Mayzent (siponimod)." Novartis Pharmaceuticals Australia Pty Ltd

Food/lifestyle interactions

No alcohol/food interactions were found. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.

Disease interactions

16 potential interactions Applies to: 15 conditions, including Multiple Sclerosis, Fever, Heart Disease, Diabetes Mellitus, and Liver Disease.

Bleeding Disorder

Major:

uracil mustard

Uracil mustard has a major potential interaction with Bleeding Disorder.

The use of uracil mustard has been associated with a dose-related myelosuppression and irreversible bone marrow failure. Therapy with uracil mustard should be administered cautiously in patients whose bone marrow reserve may be severely depressed by prior chemotherapy or irradiation or whose marrow function is recovering from previous cytotoxic therapy. Uracil mustard should be withheld until white blood cell count exceeds 3,000/mm3 and/or platelet count exceeds 100,000/mm3. Patients should be instructed to immediately report any signs or symptoms suggesting bone marrow suppression such as fever, sore throat, local infection, or bleeding. Close clinical monitoring of hematopoietic function is recommended.

Bone Marrow Depression/Low Blood Counts

Major:

uracil mustard

Uracil mustard has a major potential interaction with Bone Marrow Depression/Low Blood Counts.

The use of uracil mustard is contraindicated in patients with severe leukopenia or thrombocytopenia. Uracil mustard has a cumulative toxic effect against the bone marrow. Patients should be instructed to immediately report any signs or symptoms suggesting bone marrow suppression such as fever, sore throat, local infection, or bleeding. If severe bone marrow suppression occurs, uracil mustard should be discontinued. An accumulated dose of 1 mg/kg is associated with an increased risk of irreversible bone marrow suppression. Close clinical monitoring of hematopoietic function is recommended.

Cardiovascular Conditions and Disorders

Major:

Mayzent

The siponimod in Mayzent has a major potential interaction with Cardiovascular Conditions and Disorders.

Siponimod is contraindicated in patients who in the last 6 months experienced myocardial infarction, unstable angina, stroke, TIA, decompensated heart failure requiring hospitalization, or Class III or IV heart failure. It is also contraindicated in presence of Mobitz type II second- degree, third-degree AV block, or sick sinus syndrome, unless the patient has a functioning pacemaker. Siponimod causes a transient decrease in heart rate and atrioventricular conduction delays, and has not been studied in patients with significant QT prolongation (greater than 500 msec) or arrhythmias requiring Class Ia or Class III antiarrhythmic drugs. If treatment with siponimod is considered in these patients or in patients with ischemic heart disease, heart failure, history of myocardial infarction, cerebrovascular disease or uncontrolled hypertension, an advice from a cardiologist should be sought. It is recommended to obtain a baseline EKG, and to monitor patients very closely.

Central Nervous System Disorders

Moderate:

Mayzent

The siponimod in Mayzent has a moderate potential interaction with Central Nervous System Disorders.

Rare cases of posterior reversible encephalopathy syndrome (PRES) have been reported in patients receiving a sphingosine 1-phosphate receptor modulator. It is recommended to promptly schedule a complete physical and neurological examination and should consider an MRI, if a patient develops any unexpected neurological or psychiatric symptoms/signs, any symptom/sign suggestive of an increase of intracranial pressure, or accelerated neurological deterioration. Delay in diagnosis and treatment may lead to permanent neurological sequelae. Exercise care when using this agent in patients with a history of ischemic stroke or cerebral hemorrhage. Treatment should be discontinued if PRES is suspected.

Diabetes Mellitus

Moderate:

Mayzent

The siponimod in Mayzent has a moderate potential interaction with Diabetes Mellitus.

Macular edema was reported in 1.8% of patients receiving siponimod treatment, the majority of cases occurring within the first four months of therapy. Patients with a history of uveitis and patients with diabetes mellitus are at increased risk of macular edema during therapy. An ophthalmic evaluation of the fundus, including the macula, is recommended in all patients before starting treatment and at any time if there is any change in vision while taking siponimod. Patients with diabetes mellitus or a history of uveitis should have regular follow-up examinations during treatment. Continuation of therapy in patients with macular edema has not been evaluated, therefore, a decision on whether or not to discontinue treatment needs to take into account the potential benefits and risks for the individual patients.

Fever

Major:

uracil mustard

Uracil mustard has a major potential interaction with Fever.

The use of uracil mustard is contraindicated in patients with severe leukopenia or thrombocytopenia. Uracil mustard has a cumulative toxic effect against the bone marrow. Patients should be instructed to immediately report any signs or symptoms suggesting bone marrow suppression such as fever, sore throat, local infection, or bleeding. If severe bone marrow suppression occurs, uracil mustard should be discontinued. An accumulated dose of 1 mg/kg is associated with an increased risk of irreversible bone marrow suppression. Close clinical monitoring of hematopoietic function is recommended.

Heart Disease

Major:

Mayzent

The siponimod in Mayzent has a major potential interaction with Heart Disease.

Siponimod is contraindicated in patients who in the last 6 months experienced myocardial infarction, unstable angina, stroke, TIA, decompensated heart failure requiring hospitalization, or Class III or IV heart failure. It is also contraindicated in presence of Mobitz type II second- degree, third-degree AV block, or sick sinus syndrome, unless the patient has a functioning pacemaker. Siponimod causes a transient decrease in heart rate and atrioventricular conduction delays, and has not been studied in patients with significant QT prolongation (greater than 500 msec) or arrhythmias requiring Class Ia or Class III antiarrhythmic drugs. If treatment with siponimod is considered in these patients or in patients with ischemic heart disease, heart failure, history of myocardial infarction, cerebrovascular disease or uncontrolled hypertension, an advice from a cardiologist should be sought. It is recommended to obtain a baseline EKG, and to monitor patients very closely.

History - Cerebrovascular Disease

Major:

Mayzent

The siponimod in Mayzent has a major potential interaction with History - Cerebrovascular Disease.

Siponimod is contraindicated in patients who in the last 6 months experienced myocardial infarction, unstable angina, stroke, TIA, decompensated heart failure requiring hospitalization, or Class III or IV heart failure. It is also contraindicated in presence of Mobitz type II second- degree, third-degree AV block, or sick sinus syndrome, unless the patient has a functioning pacemaker. Siponimod causes a transient decrease in heart rate and atrioventricular conduction delays, and has not been studied in patients with significant QT prolongation (greater than 500 msec) or arrhythmias requiring Class Ia or Class III antiarrhythmic drugs. If treatment with siponimod is considered in these patients or in patients with ischemic heart disease, heart failure, history of myocardial infarction, cerebrovascular disease or uncontrolled hypertension, an advice from a cardiologist should be sought. It is recommended to obtain a baseline EKG, and to monitor patients very closely.

History - Myocardial Infarction

Major:

Mayzent

The siponimod in Mayzent has a major potential interaction with History - Myocardial Infarction.

Siponimod is contraindicated in patients who in the last 6 months experienced myocardial infarction, unstable angina, stroke, TIA, decompensated heart failure requiring hospitalization, or Class III or IV heart failure. It is also contraindicated in presence of Mobitz type II second- degree, third-degree AV block, or sick sinus syndrome, unless the patient has a functioning pacemaker. Siponimod causes a transient decrease in heart rate and atrioventricular conduction delays, and has not been studied in patients with significant QT prolongation (greater than 500 msec) or arrhythmias requiring Class Ia or Class III antiarrhythmic drugs. If treatment with siponimod is considered in these patients or in patients with ischemic heart disease, heart failure, history of myocardial infarction, cerebrovascular disease or uncontrolled hypertension, an advice from a cardiologist should be sought. It is recommended to obtain a baseline EKG, and to monitor patients very closely.

Infection

Major:

uracil mustard

Uracil mustard has a major potential interaction with Infection.

Because of their cytotoxic effects on rapidly proliferating tissues, antineoplastic agents frequently can, to varying extent, induce myelosuppression. The use of these drugs may be contraindicated in patients with known infectious diseases. All patients should be instructed to immediately report any signs or symptoms suggesting infection such as fever, sore throat, or local infection during antineoplastic therapy. Close clinical monitoring of hematopoietic function is recommended.

Moderate:

Mayzent

The siponimod in Mayzent has a moderate potential interaction with Infection.

Siponimod causes a dose-dependent reduction in peripheral lymphocyte count to 20%-30% of baseline values because of reversible sequestration of lymphocytes in lymphoid tissues. Initiation of treatment should be delayed in patients with severe active infection until resolution. Before initiating treatment with siponimod, results from a recent complete blood count (i.e., within 6 months or after discontinuation of prior therapy) should be reviewed. Effective diagnostic and therapeutic strategies should be employed in patients with symptoms of infection while on therapy. Suspension of treatment should be considered if a patient develops a serious infection.

Liver Disease

Moderate:

Mayzent

The siponimod in Mayzent has a moderate potential interaction with Liver Disease.

Elevations of transaminases may occur in siponimod- treated patients, therefore, transaminase and bilirubin levels should be reviewed before initiation of therapy. Patients who develop symptoms suggestive of hepatic dysfunction, such as unexplained nausea, vomiting, abdominal pain, fatigue, anorexia, rash with eosinophilia, or jaundice and/or dark urine during treatment, should have liver enzymes checked. Siponimod should be discontinued if significant liver injury is confirmed. Although there are no data to establish that patients with preexisting liver disease are at increased risk to develop elevated liver function test values when taking siponimod, caution should be exercised when using the medication in patients with a history of significant liver disease.

Multiple Sclerosis

Moderate:

Mayzent

The siponimod in Mayzent has a moderate potential interaction with Multiple Sclerosis.

Rare cases of severe exacerbation of multiple sclerosis (MS), including disease rebound, have been reported after discontinuation of sphingosine 1-phosphate receptor modulator in MS treated patients. The possibility of severe exacerbation of disease should be considered after stopping treatment with these agents. Patients should be observed for a severe increase in disability upon discontinuation and appropriate treatment should be instituted, as required.

Skin Cancer

Moderate:

Mayzent

The siponimod in Mayzent has a moderate potential interaction with Skin Cancer.

Cases of malignancies, including skin malignancies have been reported in patients treated with some sphingosine -1-receptor (S1P) receptor modulators. Skin examinations are recommended prior and during treatment in all patients, particularly in those with risk factors for skin cancer. Suspicious skin lesions should be promptly evaluated, and patients at increased risk should wear protective clothing and use sunscreen with high protection factor.

Uveitis

Moderate:

Mayzent

The siponimod in Mayzent has a moderate potential interaction with Uveitis.

Macular edema was reported in 1.8% of patients receiving siponimod treatment, the majority of cases occurring within the first four months of therapy. Patients with a history of uveitis and patients with diabetes mellitus are at increased risk of macular edema during therapy. An ophthalmic evaluation of the fundus, including the macula, is recommended in all patients before starting treatment and at any time if there is any change in vision while taking siponimod. Patients with diabetes mellitus or a history of uveitis should have regular follow-up examinations during treatment. Continuation of therapy in patients with macular edema has not been evaluated, therefore, a decision on whether or not to discontinue treatment needs to take into account the potential benefits and risks for the individual patients.

Vaccination

Moderate:

Mayzent

The siponimod in Mayzent has a moderate potential interaction with Vaccination.

The use of live attenuated vaccines should be avoided while patients are taking siponimod and for 4 weeks after stopping treatment. Vaccinations may be less effective if administered during treatment. Siponimod treatment discontinuation 1 week prior to and until 4 weeks after a planned vaccination is recommended. Additionally, patients without a healthcare professional confirmed history of chickenpox or without documentation of a full course of vaccination against varicella zoster virus (VZV) should be tested for antibodies to VZV before initiating siponimod treatment. A full course of vaccination for antibody- negative patients with varicella vaccine is recommended prior to commencing treatment, following which initiation of treatment with siponimod should be postponed for 4 weeks to allow the full effect of vaccination to occur.

More resources

Mayzent

A total of 779 drugs are known to interact with Mayzent.

uracil mustard

A total of 221 drugs are known to interact with uracil mustard.

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor 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.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.