Interactions between Modafinil and Phenylfenesin
3 drug interactions and 26 additional warnings found for the following 2 drugs:
- modafinil
- Phenylfenesin (guaifenesin/phenylephrine/phenylpropanolamine)
Drug interactions
Moderate drug interactions
Moderate:
phenylephrine phenylpropanolamine
Applies to: Phenylfenesin (guaifenesin / phenylephrine / phenylpropanolamine) and Phenylfenesin (guaifenesin / phenylephrine / phenylpropanolamine)
Monitor
Coadministration of two or more sympathomimetic decongestants may produce additive adrenergic effects and increase the risk of hypertension, tachycardia, palpitations, nervousness, agitation, and other cardiovascular or central nervous system adverse effects. Although systemic absorption following recommended intranasal use may be limited, systemic cardiovascular and neurological adverse effects may occur, particularly with excessive or prolonged use.
Management
Caution is advised if two or more sympathomimetic decongestants are coadministered. Pulse and blood pressure should be closely monitored. Some manufacturers consider the concomitant use of two or more sympathomimetic decongestants contraindicated. Individual product labeling and relevant institutional protocols should be consulted for further guidance, as more restrictive recommendations, including contraindications, may apply to specific products or formulations.
References (4)
- (2026) "Product Information. Boots Decongestant (Pseudoephedrine) (pseudoephedrine)." The Boots Company Plc
- (2023) "Product Information. Sinus and Nasal Decongestant (Trust) (pseudoephedrine)." Noumed Pharmaceuticals Pty Ltd
- (2024) "Product Information. Lemsip Cough Max for Mucus Cough and Cold (guaifenesin/paracetamol/phenylephrine)." Reckitt Benckiser Healthcare (UK) Ltd
- emc (2026) Product information: sudafed plus blocked nose 1mg/50mg/ml nasal spray. https://www.medicines.org.uk/emc/product/14256/smpc?utm_source=chatgpt.com
Moderate:
phenylephrine modafinil
Applies to: Phenylfenesin (guaifenesin / phenylephrine / phenylpropanolamine) and modafinil
Monitor
Coadministration of two or more sympathomimetic or noradrenergic agents may increase the risk of nervousness, irritability, tachycardia, and/or increased blood pressure. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic and/or noradrenergic agents, including norepinephrine transporter inhibitors. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.
Management
Caution is advised if two or more sympathomimetic or noradrenergic agents are coadministered. Pulse and blood pressure should be closely monitored. Consultation with individual product labeling, as well as relevant institutional protocols, may be advisable for further guidance.
References (20)
- Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
- Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2024) "Product Information. Ephedrine (ephedrine)." Hameln Pharma Ltd
- (2023) "Product Information. Ephedrine Hydrochloride (ephedrine)." Wockhardt UK Ltd
- (2026) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
- (2025) "Product Information. Atomoxetine (atomoxetine)." Zentiva Pharma UK Ltd
- (2026) "Product Information. Atomoxetine (Apo) (atomoxetine)." Arrotex Pharmaceuticals Pty Ltd
- Angita Pharma, Inc (2026) AG-ATOMOXETINE Product Monograph (Health Canada) https://pdf.hres.ca/dpd_pm/00059014.PDF
- (2026) "Product Information. Boots Decongestant (Pseudoephedrine) (pseudoephedrine)." The Boots Company Plc
- (2023) "Product Information. Sinus and Nasal Decongestant (Trust) (pseudoephedrine)." Noumed Pharmaceuticals Pty Ltd
- (2019) "Product Information. Ephedrine (ephedrine)." Pfizer Australia Pty Ltd
- (2024) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Amneal Pharmaceuticals LLC
- (2024) "Product Information. Lemsip Cough Max for Mucus Cough and Cold (guaifenesin/paracetamol/phenylephrine)." Reckitt Benckiser Healthcare (UK) Ltd
- emc (2026) Product information: sudafed plus blocked nose 1mg/50mg/ml nasal spray. https://www.medicines.org.uk/emc/product/14256/smpc?utm_source=chatgpt.com
- (2023) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Baxter Corporation
- Neo Health (OTC) Pty Ltd (2026) Product information: pseudoephedrine hydrochloride-paracetamol capsules. https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2024-PI-02603-1&d=20260804172310101&d=20260827172310101
Moderate:
phenylpropanolamine modafinil
Applies to: Phenylfenesin (guaifenesin / phenylephrine / phenylpropanolamine) and modafinil
Monitor
Coadministration of two or more sympathomimetic or noradrenergic agents may increase the risk of nervousness, irritability, tachycardia, and/or increased blood pressure. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic and/or noradrenergic agents, including norepinephrine transporter inhibitors. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.
Management
Caution is advised if two or more sympathomimetic or noradrenergic agents are coadministered. Pulse and blood pressure should be closely monitored. Consultation with individual product labeling, as well as relevant institutional protocols, may be advisable for further guidance.
References (20)
- Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
- Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2024) "Product Information. Ephedrine (ephedrine)." Hameln Pharma Ltd
- (2023) "Product Information. Ephedrine Hydrochloride (ephedrine)." Wockhardt UK Ltd
- (2026) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
- (2025) "Product Information. Atomoxetine (atomoxetine)." Zentiva Pharma UK Ltd
- (2026) "Product Information. Atomoxetine (Apo) (atomoxetine)." Arrotex Pharmaceuticals Pty Ltd
- Angita Pharma, Inc (2026) AG-ATOMOXETINE Product Monograph (Health Canada) https://pdf.hres.ca/dpd_pm/00059014.PDF
- (2026) "Product Information. Boots Decongestant (Pseudoephedrine) (pseudoephedrine)." The Boots Company Plc
- (2023) "Product Information. Sinus and Nasal Decongestant (Trust) (pseudoephedrine)." Noumed Pharmaceuticals Pty Ltd
- (2019) "Product Information. Ephedrine (ephedrine)." Pfizer Australia Pty Ltd
- (2024) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Amneal Pharmaceuticals LLC
- (2024) "Product Information. Lemsip Cough Max for Mucus Cough and Cold (guaifenesin/paracetamol/phenylephrine)." Reckitt Benckiser Healthcare (UK) Ltd
- emc (2026) Product information: sudafed plus blocked nose 1mg/50mg/ml nasal spray. https://www.medicines.org.uk/emc/product/14256/smpc?utm_source=chatgpt.com
- (2023) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Baxter Corporation
- Neo Health (OTC) Pty Ltd (2026) Product information: pseudoephedrine hydrochloride-paracetamol capsules. https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2024-PI-02603-1&d=20260804172310101&d=20260827172310101
Food/lifestyle interactions
Moderate food/lifestyle interactions
Moderate:
phenylpropanolamine Food/Lifestyle
Applies to: Phenylfenesin (guaifenesin / phenylephrine / phenylpropanolamine)
Generally avoid
Alcohol may potentiate the central nervous system and cardiovascular effects of centrally-acting appetite suppressants. In one study, concurrent administration of methamphetamine (30 mg intravenously) and ethanol (1 gm/kg orally over 30 minutes) increased heart rate by 24 beats/minute compared to methamphetamine alone. This increases cardiac work and myocardial oxygen consumption, which may lead to more adverse cardiovascular effects than either agent alone. Subjective effects of ethanol were diminished in the eight study subjects, but those of methamphetamine were not affected. The pharmacokinetics of methamphetamine were also unaffected except for a decrease in the apparent volume of distribution at steady state.
Management
Concomitant use of centrally-acting appetite suppressants and alcohol should be avoided if possible, especially in patients with a history of cardiovascular disease. Patients should be counselled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.
References (3)
- Mendelson J, Jones RT, Upton R, Jacob P 3rd (1995) "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther, 57, p. 559-68
- (2001) "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn
- (2012) "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals
Moderate:
phenylephrine Caffeine
Applies to: Phenylfenesin (guaifenesin / phenylephrine / phenylpropanolamine)
Monitor
Coadministration of two or more sympathomimetic or noradrenergic agents may increase the risk of nervousness, irritability, tachycardia, and/or increased blood pressure. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic and/or noradrenergic agents, including norepinephrine transporter inhibitors. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.
Management
Caution is advised if two or more sympathomimetic or noradrenergic agents are coadministered. Pulse and blood pressure should be closely monitored. Consultation with individual product labeling, as well as relevant institutional protocols, may be advisable for further guidance.
References (20)
- Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
- Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2024) "Product Information. Ephedrine (ephedrine)." Hameln Pharma Ltd
- (2023) "Product Information. Ephedrine Hydrochloride (ephedrine)." Wockhardt UK Ltd
- (2026) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
- (2025) "Product Information. Atomoxetine (atomoxetine)." Zentiva Pharma UK Ltd
- (2026) "Product Information. Atomoxetine (Apo) (atomoxetine)." Arrotex Pharmaceuticals Pty Ltd
- Angita Pharma, Inc (2026) AG-ATOMOXETINE Product Monograph (Health Canada) https://pdf.hres.ca/dpd_pm/00059014.PDF
- (2026) "Product Information. Boots Decongestant (Pseudoephedrine) (pseudoephedrine)." The Boots Company Plc
- (2023) "Product Information. Sinus and Nasal Decongestant (Trust) (pseudoephedrine)." Noumed Pharmaceuticals Pty Ltd
- (2019) "Product Information. Ephedrine (ephedrine)." Pfizer Australia Pty Ltd
- (2024) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Amneal Pharmaceuticals LLC
- (2024) "Product Information. Lemsip Cough Max for Mucus Cough and Cold (guaifenesin/paracetamol/phenylephrine)." Reckitt Benckiser Healthcare (UK) Ltd
- emc (2026) Product information: sudafed plus blocked nose 1mg/50mg/ml nasal spray. https://www.medicines.org.uk/emc/product/14256/smpc?utm_source=chatgpt.com
- (2023) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Baxter Corporation
- Neo Health (OTC) Pty Ltd (2026) Product information: pseudoephedrine hydrochloride-paracetamol capsules. https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2024-PI-02603-1&d=20260804172310101&d=20260827172310101
Moderate:
phenylpropanolamine Caffeine
Applies to: Phenylfenesin (guaifenesin / phenylephrine / phenylpropanolamine)
Monitor
Coadministration of two or more sympathomimetic or noradrenergic agents may increase the risk of nervousness, irritability, tachycardia, and/or increased blood pressure. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic and/or noradrenergic agents, including norepinephrine transporter inhibitors. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.
Management
Caution is advised if two or more sympathomimetic or noradrenergic agents are coadministered. Pulse and blood pressure should be closely monitored. Consultation with individual product labeling, as well as relevant institutional protocols, may be advisable for further guidance.
References (20)
- Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
- Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2024) "Product Information. Ephedrine (ephedrine)." Hameln Pharma Ltd
- (2023) "Product Information. Ephedrine Hydrochloride (ephedrine)." Wockhardt UK Ltd
- (2026) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
- (2025) "Product Information. Atomoxetine (atomoxetine)." Zentiva Pharma UK Ltd
- (2026) "Product Information. Atomoxetine (Apo) (atomoxetine)." Arrotex Pharmaceuticals Pty Ltd
- Angita Pharma, Inc (2026) AG-ATOMOXETINE Product Monograph (Health Canada) https://pdf.hres.ca/dpd_pm/00059014.PDF
- (2026) "Product Information. Boots Decongestant (Pseudoephedrine) (pseudoephedrine)." The Boots Company Plc
- (2023) "Product Information. Sinus and Nasal Decongestant (Trust) (pseudoephedrine)." Noumed Pharmaceuticals Pty Ltd
- (2019) "Product Information. Ephedrine (ephedrine)." Pfizer Australia Pty Ltd
- (2024) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Amneal Pharmaceuticals LLC
- (2024) "Product Information. Lemsip Cough Max for Mucus Cough and Cold (guaifenesin/paracetamol/phenylephrine)." Reckitt Benckiser Healthcare (UK) Ltd
- emc (2026) Product information: sudafed plus blocked nose 1mg/50mg/ml nasal spray. https://www.medicines.org.uk/emc/product/14256/smpc?utm_source=chatgpt.com
- (2023) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Baxter Corporation
- Neo Health (OTC) Pty Ltd (2026) Product information: pseudoephedrine hydrochloride-paracetamol capsules. https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2024-PI-02603-1&d=20260804172310101&d=20260827172310101
Minor food/lifestyle interactions
Minor:
modafinil Food/Lifestyle
Applies to: modafinil
Administration with food may delay the absorption of modafinil (the racemate) and armodafinil (the R-enantiomer) without significantly affecting their overall bioavailability. According to the product labeling, modafinil's absorption may be delayed by approximately one hour if taken with food. Similarly, the time to reach peak plasma concentration (Tmax) of armodafinil may be delayed by approximately 2 to 4 hours in the fed state.
References (2)
- (2001) "Product Information. Provigil (modafinil)." Cephalon, Inc
- (2007) "Product Information. Nuvigil (armodafinil)." Cephalon Inc
Disease interactions
22 potential interactions Applies to: 19 conditions, including High Blood Pressure, Depression, Benign Prostatic Hyperplasia, Angina, and Arrhythmia.
Alcoholism
Moderate:
modafinil
Modafinil has a moderate potential interaction with Alcoholism.
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.
Angina
Moderate:
modafinil
Modafinil has a moderate potential interaction with 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.
Arrhythmia
Moderate:
modafinil
Modafinil has a moderate potential interaction with Arrhythmia.
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.
Benign Prostatic Hyperplasia
Moderate:
Phenylfenesin
The phenylephrine and phenylpropanolamine in Phenylfenesin both have a moderate potential interaction with Benign Prostatic Hyperplasia.
Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors. Therapy with sympathomimetic agents should be administered cautiously in patients with hypertrophy or neoplasm of the prostate.
Cardiovascular Conditions and Disorders
Major:
Phenylfenesin
The phenylephrine and phenylpropanolamine in Phenylfenesin both have a major potential interaction with Cardiovascular Conditions and Disorders.
Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.
Moderate:
modafinil
Modafinil has a moderate potential interaction with Cardiovascular Conditions and Disorders.
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.
Cerebrovascular Insufficiency
Major:
Phenylfenesin
The phenylephrine and phenylpropanolamine in Phenylfenesin both have a major potential interaction with Cerebrovascular Insufficiency.
Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.
Depression
Major:
modafinil
Modafinil has a major potential interaction with Depression.
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.
Diabetes Mellitus
Moderate:
Phenylfenesin
The phenylephrine and phenylpropanolamine in Phenylfenesin both have a moderate potential interaction with Diabetes Mellitus.
Sympathomimetic agents may cause increases in blood glucose concentrations. These effects are usually transient and slight but may be significant with dosages higher than those normally recommended. Therapy with sympathomimetic agents should be administered cautiously in patients with diabetes mellitus. Closer monitoring of blood glucose concentrations may be appropriate.
Drug Dependence
Moderate:
modafinil
Modafinil has a moderate potential interaction with Drug Dependence.
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.
Glaucoma/Intraocular Hypertension
Moderate:
Phenylfenesin
The phenylephrine and phenylpropanolamine in Phenylfenesin both have a moderate potential interaction with Glaucoma/Intraocular Hypertension.
Sympathomimetic agents can induce transient mydriasis via stimulation of alpha-1 adrenergic receptors. In patients with anatomically narrow angles or narrow-angle glaucoma, pupillary dilation can provoke an acute attack. In patients with other forms of glaucoma, mydriasis may occasionally increase intraocular pressure. Therapy with sympathomimetic agents should be administered cautiously in patients with or predisposed to glaucoma, particularly narrow-angle glaucoma.
Heart Disease
Moderate:
modafinil
Modafinil has a moderate potential interaction with Heart Disease.
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.
High Blood Pressure
Major:
modafinil
Modafinil has a major potential interaction with High Blood Pressure.
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.
Moderate:
modafinil
Modafinil has a moderate potential interaction with High Blood Pressure.
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.
History - Myocardial Infarction
Moderate:
modafinil
Modafinil has a moderate potential interaction with History - Myocardial Infarction.
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.
Hyperthyroidism
Major:
Phenylfenesin
The phenylephrine and phenylpropanolamine in Phenylfenesin both have a major potential interaction with Hyperthyroidism.
Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.
Liver Disease
Moderate:
modafinil
Modafinil has a moderate potential interaction with Liver Disease.
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.
Pheochromocytoma
Major:
Phenylfenesin
The phenylephrine in Phenylfenesin has a major potential interaction with Pheochromocytoma.
Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.
Prostate Tumor, Benign
Moderate:
Phenylfenesin
The phenylephrine and phenylpropanolamine in Phenylfenesin both have a moderate potential interaction with Prostate Tumor, Benign.
Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors. Therapy with sympathomimetic agents should be administered cautiously in patients with hypertrophy or neoplasm of the prostate.
Psychiatric Disorders
Moderate:
Phenylfenesin
The phenylpropanolamine in Phenylfenesin has a moderate potential interaction with Psychiatric Disorders.
Phenylpropanolamine may precipitate or exacerbate psychotic symptoms, particularly at high dosages. Therapy with phenylpropanolamine should be administered cautiously in patients with a history of psychiatric disorders.
Psychosis
Major:
modafinil
Modafinil has a major potential interaction with Psychosis.
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.
Moderate:
Phenylfenesin
The phenylpropanolamine in Phenylfenesin has a moderate potential interaction with Psychosis.
Phenylpropanolamine may precipitate or exacerbate psychotic symptoms, particularly at high dosages. Therapy with phenylpropanolamine should be administered cautiously in patients with a history of psychiatric disorders.
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modafinil
A total of 551 drugs are known to interact with modafinil.
- Modafinil is in the drug class CNS stimulants.
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Modafinil is used to treat the following conditions:
- ADHD (off-label)
- Chronic Fatigue Syndrome (off-label)
- Depression (off-label)
- Fatigue (off-label)
- Idiopathic Hypersomnia (off-label)
- Narcolepsy
- Obstructive Sleep Apnea/Hypopnea Syndrome
- Shift Work Sleep Disorder
Phenylfenesin
A total of 268 drugs are known to interact with Phenylfenesin.
- Phenylfenesin is in the drug class upper respiratory combinations.
- Phenylfenesin is used to treat Cold Symptoms.
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. |
Further information
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