Drug Interactions between modafinil and quinine

Information for this minor interaction is available on the professional version.

Information for this minor interaction is available on the professional version.

The use of certain antimalarial agents is contraindicated in patients with known prolongation of QT interval as these patients can develop fatal arrhythmias. These drugs should also be avoided in patients with clinical conditions known to prolong the QT interval, such as uncorrected hypokalemia or hypomagnesemia, bradycardia, and certain other cardiac conditions. Caution is advised in patients taking other medications that can prolong the QT interval.

The use of CNS stimulants can cause psychotic symptoms, suicidal ideation, and aggression, and can exacerbate symptoms of behavior disturbance and thought disorder; CNS stimulants may induce a manic or mixed episode in patients with bipolar disorder. Psychiatric symptoms have been reported in patients with and without history of psychiatric disorders. All patients (particularly those with psychotic or bipolar disorders) should be monitored closely, especially during treatment initiation and at times of dose changes. Extreme caution should be exercised when CNS stimulants are given to patients with a history of psychosis, depression, mania, or bipolar disorder. Prior to initiating therapy, all patients should be screened for risk factors for developing a manic episode (e.g., comorbid or history of depressive symptoms or family history of suicide, bipolar disease, or depression). If any psychiatric symptoms emerge or are exacerbated, treatment suspension should be considered. Some CNS stimulants are contraindicated in patients with marked agitation or anxiety.

The use of quinine is contraindicated in patients with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. Red blood cells are more easily destroyed in patients with G-6-PD deficiency and may lead to hemolysis and anemia.

CNS stimulants increase blood pressure and heart rate; the use of some agents may be contraindicated in patients with severe/uncontrolled hypertension. Caution should be used when administering to patients with preexisting high blood pressure (even mild hypertension) and other cardiovascular conditions. All patients under treatment should be regularly monitored for potential tachycardia and hypertension.

The use of certain antimalarial agents is contraindicated in patients with known prolongation of QT interval as these patients can develop fatal arrhythmias. These drugs should also be avoided in patients with clinical conditions known to prolong the QT interval, such as uncorrected hypokalemia or hypomagnesemia, bradycardia, and certain other cardiac conditions. Caution is advised in patients taking other medications that can prolong the QT interval.

The use of certain antimalarial agents is contraindicated in patients with known prolongation of QT interval as these patients can develop fatal arrhythmias. These drugs should also be avoided in patients with clinical conditions known to prolong the QT interval, such as uncorrected hypokalemia or hypomagnesemia, bradycardia, and certain other cardiac conditions. Caution is advised in patients taking other medications that can prolong the QT interval.

The use of quinine is contraindicated in patients with myasthenia gravis, as quinine has neuromuscular blocking activity, and may exacerbate muscle weakness.

The use of CNS stimulants can cause psychotic symptoms, suicidal ideation, and aggression, and can exacerbate symptoms of behavior disturbance and thought disorder; CNS stimulants may induce a manic or mixed episode in patients with bipolar disorder. Psychiatric symptoms have been reported in patients with and without history of psychiatric disorders. All patients (particularly those with psychotic or bipolar disorders) should be monitored closely, especially during treatment initiation and at times of dose changes. Extreme caution should be exercised when CNS stimulants are given to patients with a history of psychosis, depression, mania, or bipolar disorder. Prior to initiating therapy, all patients should be screened for risk factors for developing a manic episode (e.g., comorbid or history of depressive symptoms or family history of suicide, bipolar disease, or depression). If any psychiatric symptoms emerge or are exacerbated, treatment suspension should be considered. Some CNS stimulants are contraindicated in patients with marked agitation or anxiety.

Quinine is contraindicated in patients with thrombocytopenia. Quinine can produce an immune-mediated thrombocytopenia. Severe cases of thrombocytopenia that are fatal or life threatening have been reported. Chronic renal impairment associated with the development of TTP has also been reported. Thrombocytopenia usually resolves within a week upon discontinuation of quinine. If quinine is not stopped, patients can be at risk for fatal hemorrhage. Upon re- exposure to quinine from any source, a patient with quinine- dependent antibodies could develop thrombocytopenia that is more rapid in onset and more severe than the original episode.

The use of quinine is contraindicated in patients with tinnitus. Quinine has been associated with reversible and irreversible ototoxicity. Reversible hearing loss, tinnitus, and dizziness has been reported in 20% of patients receiving therapeutic doses of quinine. Cystic degeneration of stria vascularis, degeneration of the cochlear neurons, and loss of hair cells occur. Injury may be produced by spasm of cochlear blood vessels, resulting in anoxia and subsequent cellular damage.

The use of quinine is contraindicated in patients with optic neuritis, and cautious use, if at all, is advised for patients with retinopathy or other visual defects. Quinine may affect the retina and optic nerve, producing visual disturbances that include blurred vision with scotomata, photophobia, diplopia, constricted visual fields, night blindness, and abnormal color perception. Although ocular toxicity is usually reversible following drug withdrawal, retinopathy and optic atrophy can occur in severe cases. All patients should be advised to immediately discontinue the drug and contact a physician if visual disturbances occur or are exacerbated during quinine therapy.

Patients with a history of drug and/or stimulant abuse should be closely followed during treatment with modafinil. Observe patients for signs of misuse and abuse. Clinical studies indicate modafinil produces psychoactive and euphoric effects/feelings consistent with other CNS stimulants.

Modafinil is not recommended for use in patients with a history of left ventricular hypertrophy or ischemic ECG changes, chest pain, arrhythmia or other clinically significant manifestations of mitral valve prolapse in association with central nervous system stimulant use. Increased monitoring of heart rate and blood pressure is recommended in patients taking modafinil. Caution is advised in patients with known cardiovascular disease and increased monitoring is recommended in patients with a recent history of myocardial infarction or unstable angina.

Modafinil is not recommended for use in patients with a history of left ventricular hypertrophy or ischemic ECG changes, chest pain, arrhythmia or other clinically significant manifestations of mitral valve prolapse in association with central nervous system stimulant use. Increased monitoring of heart rate and blood pressure is recommended in patients taking modafinil. Caution is advised in patients with known cardiovascular disease and increased monitoring is recommended in patients with a recent history of myocardial infarction or unstable angina.

Modafinil is not recommended for use in patients with a history of left ventricular hypertrophy or ischemic ECG changes, chest pain, arrhythmia or other clinically significant manifestations of mitral valve prolapse in association with central nervous system stimulant use. Increased monitoring of heart rate and blood pressure is recommended in patients taking modafinil. Caution is advised in patients with known cardiovascular disease and increased monitoring is recommended in patients with a recent history of myocardial infarction or unstable angina.

Patients with a history of drug and/or stimulant abuse should be closely followed during treatment with modafinil. Observe patients for signs of misuse and abuse. Clinical studies indicate modafinil produces psychoactive and euphoric effects/feelings consistent with other CNS stimulants.

Modafinil is not recommended for use in patients with a history of left ventricular hypertrophy or ischemic ECG changes, chest pain, arrhythmia or other clinically significant manifestations of mitral valve prolapse in association with central nervous system stimulant use. Increased monitoring of heart rate and blood pressure is recommended in patients taking modafinil. Caution is advised in patients with known cardiovascular disease and increased monitoring is recommended in patients with a recent history of myocardial infarction or unstable angina.

Modafinil is not recommended for use in patients with a history of left ventricular hypertrophy or ischemic ECG changes, chest pain, arrhythmia or other clinically significant manifestations of mitral valve prolapse in association with central nervous system stimulant use. Increased monitoring of heart rate and blood pressure is recommended in patients taking modafinil. Caution is advised in patients with known cardiovascular disease and increased monitoring is recommended in patients with a recent history of myocardial infarction or unstable angina.

Modafinil is not recommended for use in patients with a history of left ventricular hypertrophy or ischemic ECG changes, chest pain, arrhythmia or other clinically significant manifestations of mitral valve prolapse in association with central nervous system stimulant use. Increased monitoring of heart rate and blood pressure is recommended in patients taking modafinil. Caution is advised in patients with known cardiovascular disease and increased monitoring is recommended in patients with a recent history of myocardial infarction or unstable angina.

In patients with severe hepatic impairment (Child-Pugh C), quinine oral clearance is decreased, volume of distribution is increased, and half-life is prolonged, relative to subjects with normal liver function. Therefore, quinine is not indicated in patients with severe hepatic impairment and alternate therapy should be administered. Adjustment of the recommended dose is not required in mild (Child-Pugh A) or moderate (Child-Pugh B) hepatic impairment, but patients should be monitored closely for adverse effects of quinine.

Exposure to modafinil is increased in patients with liver dysfunction. In patients with severe liver dysfunction, reduce the dose of modafinil to one-half the dose recommended dose.

Clearance of quinine is decreased in patients with severe chronic renal failure. The dosage and dosing frequency should be reduced. The effects of mild and moderate renal impairment on the safety and pharmacokinetics of quinine sulfate are not known. Monitoring is advised.