MODAFINIL Drug Interactions: What You Need to Know

INTERACTIONS Effects of Modafinil on CYP3A4/5 Substrates The clearance of drugs that are substrates for CYP3A4/5 (e.g., steroidal contraceptives, cyclosporine, midazolam, and triazolam) may be increased by modafinil via induction of metabolic enzymes, which results in lower systemic exposure. Dosage adjustment of these drugs should be considered when these drugs are used concomitantly with modafinil [see Clinical Pharmacology (12.3) ] . The effectiveness of steroidal contraceptives may be reduced when used with modafinil and for one month after discontinuation of therapy. Alternative or concomitant methods of contraception are recommended for patients taking steroidal contraceptives (e.g., ethinyl estradiol) when treated concomitantly with modafinil and for one month after discontinuation of modafinil treatment. Blood levels of cyclosporine may be reduced when used with modafinil. Monitoring of circulating cyclosporine concentrations and appropriate dosage adjustment for cyclosporine should be considered when used concomitantly with modafinil. Effects of Modafinil on CYP2C19 Substrates Elimination of drugs that are substrates for CYP2C19 (e.g., phenytoin, diazepam, propranolol, omeprazole, and clomipramine) may be prolonged by modafinil via inhibition of metabolic enzymes, with resultant higher systemic exposure. In individuals deficient in the CYP2D6 enzyme, the levels of CYP2D6 substrates which have ancillary routes of elimination through CYP2C19, such as tricyclic antidepressants and selective serotonin reuptake inhibitors, may be increased by co-administration of modafinil. Dose adjustments of these drugs and other drugs that are substrates for CYP2C19 may be necessary when used concomitantly with modafinil [see Clinical Pharmacology (12.3) ] .

Warfarin

More frequent monitoring of prothrombin times/INR should be considered whenever modafinil is coadministered with warfarin [see Clinical Pharmacology (12.3) ] .

Monoamine

Oxidase (MAO)

Inhibitors

Caution should be used when concomitantly administering MAO inhibitors and modafinil. To report SUSPECTED ADVERSE REACTIONS contact AvKARE, Inc. at 1-855-361-3993; email [email protected] ; or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . Steroidal contraceptives (e.g., ethinyl estradiol): Use alternative or concomitant methods of contraception while taking modafinil and for one month after discontinuation of modafinil treatment. (7) Cyclosporine: Blood concentrations of cyclosporine may be reduced. (7) CYP2C19 substrates, such as omeprazole, phenytoin, and diazepam: Exposure of these medications may be increased. (7)

Modafinil tablets are contraindicated in patients with known hypersensitivity to modafinil or armodafinil or its inactive ingredients [see Warnings and Precautions ( 5.1 , 5.2 , 5.3 )] . Modafinil tablets are contraindicated in patients with known hypersensitivity to modafinil or armodafinil. ( 4 )

AND PRECAUTIONS

• Serious Rash, including Stevens - Johnson Syndrome: Discontinue Modafinil tablets at the first sign of rash, unless the rash is clearly not drug-related. (5.1)
• Angioedema and Anaphylaxis Reactions: If suspected, discontinue modafinil tablets. (5.2)
• Multi-organ Hypersensitivity Reactions: If suspected, discontinue modafinil tablets. (5.3)
• Persistent Sleepiness: Assess patients frequently for degree of sleepiness and, if appropriate, advise patients to avoid driving or engaging in any other potentially dangerous activity. (5.4)
• Psychiatric Symptoms: Use caution in patients with a history of psychosis, depression, or mania. Consider discontinuing modafinil tablets if psychiatric symptoms develop. (5.5)
• Known Cardiovascular Disease: Consider increased monitoring. (5.7)

5.1 Serious Rash, including Stevens - Johnson Syndrome Serious rash requiring hospitalization and discontinuation of treatment has been reported in association with the use of modafinil. In clinical trials of modafinil, the incidence of rash resulting in discontinuation was approximately 0.8% (13 per 1,585) in pediatric patients (age &lt;17 years); these rashes included 1 case of possible Stevens - Johnson Syndrome (SJS) and 1 case of apparent multi-organ hypersensitivity reaction. Several of the cases were associated with fever and other abnormalities (e.g., vomiting, leukopenia). The median time to rash that resulted in discontinuation was 13 days. No such cases were observed among 380 pediatric patients who received placebo. Modafinil tablets are not approved for use in pediatric patients for any indication <span class="opacity-50 text-xs">[see Use in Specific Populations (8.4) ]</span>. Rare cases of serious or life-threatening rash, including SJS, Toxic Epidermal Necrolysis (TEN), and Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) have been reported in adults and children in worldwide postmarketing experience. The reporting rate of TEN and SJS associated with modafinil use, which is generally accepted to be an underestimate due to underreporting, exceeds the background incidence rate. Estimates of the background incidence rate for these serious skin reactions in the general population range between 1 to 2 cases per million-person years. There are no factors that are known to predict the risk of occurrence or the severity of rash associated with modafinil tablets. Nearly all cases of serious rash associated with modafinil occurred within 1 to 5 weeks after treatment initiation. However, isolated cases have been reported after prolonged treatment (e.g., 3 months). Accordingly, duration of therapy cannot be relied upon as a means to predict the potential risk heralded by the first appearance of a rash. Although benign rashes also occur with modafinil tablets, it is not possible to reliably predict which rashes will prove to be serious. Accordingly, modafinil tablets should be discontinued at the first sign of rash, unless the rash is clearly not drug-related. Discontinuation of treatment may not prevent a rash from becoming life-threatening or permanently disabling or disfiguring.

5.2 Angioedema and Anaphylaxis Reactions Angioedema and hypersensitivity (with rash, dysphagia, and bronchospasm), were observed in patients treated with armodafinil, the R enantiomer of modafinil (which is the racemic mixture). No such cases were observed in modafinil clinical trials. However, angioedema has been reported in postmarketing experience with modafinil. Patients should be advised to discontinue therapy and immediately report to their physician any signs or symptoms suggesting angioedema or anaphylaxis (e.g., swelling of face, eyes, lips, tongue or larynx; difficulty in swallowing or breathing; hoarseness).

5.3 Multi-organ Hypersensitivity Reactions Multi-organ hypersensitivity reactions, including at least one fatality in postmarketing experience, have occurred in close temporal association (median time to detection 13 days: range 4-33) to the initiation of modafinil. Although there have been a limited number of reports, multi-organ hypersensitivity reactions may result in hospitalization or be life-threatening. There are no factors that are known to predict the risk of occurrence or the severity of multi-organ hypersensitivity reactions. Signs and symptoms of this disorder were diverse; however, patients typically, although not exclusively, presented with fever and rash associated with other organ system involvement. Other associated manifestations included myocarditis, hepatitis, liver function test abnormalities, hematological abnormalities (e.g., eosinophilia, leukopenia, thrombocytopenia), pruritus, and asthenia. Because multi-organ hypersensitivity is variable in its expression, other organ system symptoms and signs, not noted here, may occur. If a multi-organ hypersensitivity reaction is suspected, modafinil tablets should be discontinued. Although there are no case reports to indicate cross-sensitivity with other drugs that produce this syndrome, the experience with drugs associated with multi-organ hypersensitivity would indicate this to be a possibility.

5.4 Persistent Sleepiness Patients with abnormal levels of sleepiness who take modafinil tablets should be advised that their level of wakefulness may not return to normal. Patients with excessive sleepiness, including those taking modafinil tablets, should be frequently reassessed for their degree of sleepiness and, if appropriate, advised to avoid driving or any other potentially dangerous activity. Prescribers should also be aware that patients may not acknowledge sleepiness or drowsiness until directly questioned about drowsiness or sleepiness during specific activities.

5.5 Psychiatric Symptoms Psychiatric adverse reactions have been reported in patients treated with modafinil. In the adult modafinil tablets controlled trials, psychiatric symptoms resulting in treatment discontinuation (at a frequency ≥0.3%) and reported more often in patients treated with modafinil tablets compared to those treated with placebo were anxiety (1%), nervousness (1%), insomnia (&lt;1%), confusion (&lt;1%), agitation (&lt;1%), and depression (&lt;1%). Postmarketing adverse reactions associated with the use of modafinil have included mania, delusions, hallucinations, suicidal ideation, and aggression, some resulting in hospitalization. Many, but not all, patients had a prior psychiatric history. One healthy male volunteer developed ideas of reference, paranoid delusions, and auditory hallucinations in association with multiple daily 600 mg doses of modafinil tablets (three times the recommended dose) and sleep deprivation. There was no evidence of psychosis 36 hours after drug discontinuation. Caution should be exercised when modafinil tablets are given to patients with a history of psychosis, depression, or mania. Consideration should be given to the possible emergence or exacerbation of psychiatric symptoms in patients treated with modafinil tablets. If psychiatric symptoms develop in association with modafinil tablets administration, consider discontinuing modafinil tablets.

5.6 Effects on Ability to Drive and Use Machinery Although modafinil tablets has not been shown to produce functional impairment, any drug affecting the CNS may alter judgment, thinking or motor skills. Patients should be cautioned about operating an automobile or other hazardous machinery until it is reasonably certain that modafinil tablets therapy will not adversely affect their ability to engage in such activities.

5.7 Cardiovascular Events In modafinil clinical studies, cardiovascular adverse reactions, including chest pain, palpitations, dyspnea, and transient ischemic T-wave changes on ECG occurred in three subjects in association with mitral valve prolapse or left ventricular hypertrophy. In a Canadian clinical trial, a 35 year old obese narcoleptic male with a prior history of syncopal episodes experienced a 9-second episode of asystole after 27 days of modafinil treatment (300 mg/day in divided doses). Modafinil tablets are not recommended in patients with a history of left ventricular hypertrophy or in patients with mitral valve prolapse who have experienced the mitral valve prolapse syndrome when previously receiving CNS stimulants. Findings suggestive of mitral valve prolapse syndrome include but are not limited to ischemic ECG changes, chest pain, or arrhythmia. If new onset of any of these findings occurs, consider cardiac evaluation. Consider increased monitoring in patients with a recent history of myocardial infarction or unstable angina. Blood pressure monitoring in short term (≤3 months) controlled trials showed no clinically significant changes in mean systolic and diastolic blood pressure in patients receiving modafinil tablets as compared to placebo. However, a retrospective analysis of the use of antihypertensive medication in these studies showed that a greater proportion of patients on modafinil tablets required new or increased use of antihypertensive medications (2.4%) compared to patients on placebo (0.7%). The differential use was slightly larger when only studies in OSA were included, with 3.4% of patients on modafinil tablets and 1.1% of patients on placebo requiring such alterations in the use of antihypertensive medication. Increased monitoring of heart rate and blood pressure may be appropriate in patients on modafinil tablets. Caution should be exercised when prescribing modafinil tablets to patients with known cardiovascular disease.

5.1 Serious Rash, including Stevens - Johnson Syndrome Serious rash requiring hospitalization and discontinuation of treatment has been reported in association with the use of modafinil. In clinical trials of modafinil, the incidence of rash resulting in discontinuation was approximately 0.8% (13 per 1,585) in pediatric patients (age &lt;17 years); these rashes included 1 case of possible Stevens - Johnson Syndrome (SJS) and 1 case of apparent multi-organ hypersensitivity reaction. Several of the cases were associated with fever and other abnormalities (e.g., vomiting, leukopenia). The median time to rash that resulted in discontinuation was 13 days. No such cases were observed among 380 pediatric patients who received placebo. Modafinil tablets are not approved for use in pediatric patients for any indication <span class="opacity-50 text-xs">[see Use in Specific Populations (8.4) ]</span>. Rare cases of serious or life-threatening rash, including SJS, Toxic Epidermal Necrolysis (TEN), and Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) have been reported in adults and children in worldwide postmarketing experience. The reporting rate of TEN and SJS associated with modafinil use, which is generally accepted to be an underestimate due to underreporting, exceeds the background incidence rate. Estimates of the background incidence rate for these serious skin reactions in the general population range between 1 to 2 cases per million-person years. There are no factors that are known to predict the risk of occurrence or the severity of rash associated with modafinil tablets. Nearly all cases of serious rash associated with modafinil occurred within 1 to 5 weeks after treatment initiation. However, isolated cases have been reported after prolonged treatment (e.g., 3 months). Accordingly, duration of therapy cannot be relied upon as a means to predict the potential risk heralded by the first appearance of a rash. Although benign rashes also occur with modafinil tablets, it is not possible to reliably predict which rashes will prove to be serious. Accordingly, modafinil tablets should be discontinued at the first sign of rash, unless the rash is clearly not drug-related. Discontinuation of treatment may not prevent a rash from becoming life-threatening or permanently disabling or disfiguring.

5.2 Angioedema and Anaphylaxis Reactions Angioedema and hypersensitivity (with rash, dysphagia, and bronchospasm), were observed in patients treated with armodafinil, the R enantiomer of modafinil (which is the racemic mixture). No such cases were observed in modafinil clinical trials. However, angioedema has been reported in postmarketing experience with modafinil. Patients should be advised to discontinue therapy and immediately report to their physician any signs or symptoms suggesting angioedema or anaphylaxis (e.g., swelling of face, eyes, lips, tongue or larynx; difficulty in swallowing or breathing; hoarseness).

5.3 Multi-organ Hypersensitivity Reactions Multi-organ hypersensitivity reactions, including at least one fatality in postmarketing experience, have occurred in close temporal association (median time to detection 13 days: range 4-33) to the initiation of modafinil. Although there have been a limited number of reports, multi-organ hypersensitivity reactions may result in hospitalization or be life-threatening. There are no factors that are known to predict the risk of occurrence or the severity of multi-organ hypersensitivity reactions. Signs and symptoms of this disorder were diverse; however, patients typically, although not exclusively, presented with fever and rash associated with other organ system involvement. Other associated manifestations included myocarditis, hepatitis, liver function test abnormalities, hematological abnormalities (e.g., eosinophilia, leukopenia, thrombocytopenia), pruritus, and asthenia. Because multi-organ hypersensitivity is variable in its expression, other organ system symptoms and signs, not noted here, may occur. If a multi-organ hypersensitivity reaction is suspected, modafinil tablets should be discontinued. Although there are no case reports to indicate cross-sensitivity with other drugs that produce this syndrome, the experience with drugs associated with multi-organ hypersensitivity would indicate this to be a possibility.

5.4 Persistent Sleepiness Patients with abnormal levels of sleepiness who take modafinil tablets should be advised that their level of wakefulness may not return to normal. Patients with excessive sleepiness, including those taking modafinil tablets, should be frequently reassessed for their degree of sleepiness and, if appropriate, advised to avoid driving or any other potentially dangerous activity. Prescribers should also be aware that patients may not acknowledge sleepiness or drowsiness until directly questioned about drowsiness or sleepiness during specific activities.

5.5 Psychiatric Symptoms Psychiatric adverse reactions have been reported in patients treated with modafinil. In the adult modafinil tablets controlled trials, psychiatric symptoms resulting in treatment discontinuation (at a frequency ≥0.3%) and reported more often in patients treated with modafinil tablets compared to those treated with placebo were anxiety (1%), nervousness (1%), insomnia (&lt;1%), confusion (&lt;1%), agitation (&lt;1%), and depression (&lt;1%). Postmarketing adverse reactions associated with the use of modafinil have included mania, delusions, hallucinations, suicidal ideation, and aggression, some resulting in hospitalization. Many, but not all, patients had a prior psychiatric history. One healthy male volunteer developed ideas of reference, paranoid delusions, and auditory hallucinations in association with multiple daily 600 mg doses of modafinil tablets (three times the recommended dose) and sleep deprivation. There was no evidence of psychosis 36 hours after drug discontinuation. Caution should be exercised when modafinil tablets are given to patients with a history of psychosis, depression, or mania. Consideration should be given to the possible emergence or exacerbation of psychiatric symptoms in patients treated with modafinil tablets. If psychiatric symptoms develop in association with modafinil tablets administration, consider discontinuing modafinil tablets.

5.6 Effects on Ability to Drive and Use Machinery Although modafinil tablets has not been shown to produce functional impairment, any drug affecting the CNS may alter judgment, thinking or motor skills. Patients should be cautioned about operating an automobile or other hazardous machinery until it is reasonably certain that modafinil tablets therapy will not adversely affect their ability to engage in such activities.

5.7 Cardiovascular Events In modafinil clinical studies, cardiovascular adverse reactions, including chest pain, palpitations, dyspnea, and transient ischemic T-wave changes on ECG occurred in three subjects in association with mitral valve prolapse or left ventricular hypertrophy. In a Canadian clinical trial, a 35 year old obese narcoleptic male with a prior history of syncopal episodes experienced a 9-second episode of asystole after 27 days of modafinil treatment (300 mg/day in divided doses). Modafinil tablets are not recommended in patients with a history of left ventricular hypertrophy or in patients with mitral valve prolapse who have experienced the mitral valve prolapse syndrome when previously receiving CNS stimulants. Findings suggestive of mitral valve prolapse syndrome include but are not limited to ischemic ECG changes, chest pain, or arrhythmia. If new onset of any of these findings occurs, consider cardiac evaluation. Consider increased monitoring in patients with a recent history of myocardial infarction or unstable angina. Blood pressure monitoring in short term (≤3 months) controlled trials showed no clinically significant changes in mean systolic and diastolic blood pressure in patients receiving modafinil tablets as compared to placebo. However, a retrospective analysis of the use of antihypertensive medication in these studies showed that a greater proportion of patients on modafinil tablets required new or increased use of antihypertensive medications (2.4%) compared to patients on placebo (0.7%). The differential use was slightly larger when only studies in OSA were included, with 3.4% of patients on modafinil tablets and 1.1% of patients on placebo requiring such alterations in the use of antihypertensive medication. Increased monitoring of heart rate and blood pressure may be appropriate in patients on modafinil tablets. Caution should be exercised when prescribing modafinil tablets to patients with known cardiovascular disease.