Drug Interactions between chlorpheniramine / guaifenesin / phenylephrine and fedratinib

Alcohol can increase the nervous system side effects of chlorpheniramine such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with chlorpheniramine. Do not use more than the recommended dose of chlorpheniramine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. Talk to your doctor or pharmacist if you have any questions or concerns.

Grapefruit juice can increase the blood levels of fedratinib. This may increase the risk of serious side effects such as Wernicke's encephalopathy, a potentially fatal condition of the brain associated with thiamine (vitamin B1) deficiency; low blood cell counts, which can lead to anemia, bleeding, and infections; severe diarrhea, nausea, and vomiting; problems in the liver or pancreas; and development of other cancers. You should avoid the consumption of grapefruit and grapefruit juice during treatment with fedratinib. You may take the medication with or without food, but taking it with a high-fat meal may help reduce nausea and vomiting. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. 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.

Both phenylephrine and caffeine can increase blood pressure and heart rate, and combining them may enhance these effects. Talk to your doctor before using these medications, especially if you have a history of high blood pressure or heart disease. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if your condition changes or you experience increased side effects. 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.

In a major safety study of a Janus kinase (JAK) inhibitor, tofacitinib, in rheumatoid arthritis patients 50 years and older with at least 1 cardiovascular risk factor, higher rates of all-cause mortality (including sudden cardiovascular death) and major adverse cardiovascular events (MACE) (defined as cardiovascular death, myocardial infarction, and stroke) were observed with the JAK inhibitor when compared with tumor necrosis factor (TNF) blockers. Patients who were current or past smokers had an additional increased risk. Based on a shared mechanism of action, this risk should be considered for other JAK inhibitors, including baricitinib, upadacitinib, ruxolitinib, fedratinib, ritlecitinib, deuruxolitinib, and pacritinib. Consider the benefits and risks for each individual patient prior and during treatment with JAK inhibitors, especially in patients with other cardiovascular risk factors, history of cardiovascular events, and patients who are current or past smokers. Patients should be informed about the symptoms of serious cardiovascular events and what to do if they occur.

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.

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.

Gastrointestinal (GI) toxicities are the most frequent adverse reactions reported with fedratinib; diarrhea, nausea, and vomiting occurred in more than half of patients. The median time to onset was 1 day, with 75% of cases occurring within 2 weeks of initiating therapy. Consuming a high-fat meal with fedratinib may reduce GI adverse events. Prophylactic antiemetic therapy (e.g., 5-HT3 receptor antagonists) should be considered. Treat diarrhea with antidiarrheals at the first onset of symptoms. For Grade 3 or higher nausea, vomiting, or diarrhea not responsive to supportive measures within 48 hours: Interrupt this drug until resolved to Grade 1 or less or baseline; restart dose at 100 mg/day below the last given dose.

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.

The pharmacokinetics of fedratinib have not been evaluated in patients with severe hepatic impairment (total bilirubin > 3 times ULN and any AST), and its use should be avoided on these patients.

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.

Malignancies (including lymphomas and solid tumors) have been reported in patients treated with tofacitinib, baricitinib, upadacitinib, deuruxolitinib and other Janus kinase (JAK) inhibitors used to treat inflammatory conditions. Patients who are current or past smokers are at additional increased risk of malignancies. Based on a shared mechanism of action, this risk should be considered for other JAK inhibitors, including ruxolitinib, pacritinib, and fedratinib. Before starting or continuing therapy, the benefits and risks for the individual patient should be considered, especially in patients with a known malignancy (other than successfully treated nonmelanoma skin cancer), patients who develop a malignancy during therapy, and patients who are current or past smokers. Periodic skin examination is recommended for patients who are at increased risk for skin cancer.

In a major safety study of a Janus kinase (JAK) inhibitor, tofacitinib, in rheumatoid arthritis patients 50 years and older with at least 1 cardiovascular risk factor, higher rates of all-cause mortality (including sudden cardiovascular death) and major adverse cardiovascular events (MACE) (defined as cardiovascular death, myocardial infarction, and stroke) were observed with the JAK inhibitor when compared with tumor necrosis factor (TNF) blockers. Patients who were current or past smokers had an additional increased risk. Based on a shared mechanism of action, this risk should be considered for other JAK inhibitors, including baricitinib, upadacitinib, ruxolitinib, fedratinib, ritlecitinib, deuruxolitinib, and pacritinib. Consider the benefits and risks for each individual patient prior and during treatment with JAK inhibitors, especially in patients with other cardiovascular risk factors, history of cardiovascular events, and patients who are current or past smokers. Patients should be informed about the symptoms of serious cardiovascular events and what to do if they occur.

Serious and fatal encephalopathy, including Wernicke's disease, has occurred in patients treated with fedratinib. Wernicke's encephalopathy is a neurologic emergency. Assess thiamine levels in all patients prior to starting treatment, periodically during treatment, and as clinically indicated. Do not start fedratinib in patients with thiamine deficiency; replete thiamine prior to treatment initiation. If encephalopathy is suspected, immediately discontinue fedratinib and initiate parenteral thiamine. Patients who develop any change in their mental status during treatment, including confusion or memory impairment, should be evaluated for potential encephalopathy (e.g., neurologic examination, thiamine level assessment, imaging). Monitor until symptoms resolve or improve and thiamine levels normalize.

Thrombosis (including deep venous thrombosis, pulmonary embolism, cerebral venous sinus thrombosis, and arterial thrombosis) has occurred in patients treated for inflammatory conditions with Janus kinase (JAK) inhibitors, including baricitinib, tofacitinib, deuruxolitinib and upadacitinib. Many of these adverse events were serious and some resulted in death. Based on a shared mechanism of action, this risk should be considered for other JAK inhibitors, including ruxolitinib, fedratinib, and pacritinib. In general, JAK inhibitors should be avoided in patients who may be at increased risk of thrombosis. Tofacitinib should be used at the lowest effective dose and for the shortest duration needed to achieve/maintain therapeutic response when treating ulcerative colitis. If symptoms of thrombosis occur in any patients receiving JAK inhibitors, treatment should be discontinued and patients should be evaluated promptly and treated appropriately.

Gastrointestinal (GI) toxicities are the most frequent adverse reactions reported with fedratinib; diarrhea, nausea, and vomiting occurred in more than half of patients. The median time to onset was 1 day, with 75% of cases occurring within 2 weeks of initiating therapy. Consuming a high-fat meal with fedratinib may reduce GI adverse events. Prophylactic antiemetic therapy (e.g., 5-HT3 receptor antagonists) should be considered. Treat diarrhea with antidiarrheals at the first onset of symptoms. For Grade 3 or higher nausea, vomiting, or diarrhea not responsive to supportive measures within 48 hours: Interrupt this drug until resolved to Grade 1 or less or baseline; restart dose at 100 mg/day below the last given dose.

Adverse hematologic effects including neutropenia, thrombocytopenia, and anemia have been associated with the use of fedratinib. It is recommended to modify the starting dose in patients with a baseline platelet count (PLT) less than 50 x 10(9)/L. Therapy should be interrupted until grade 4 thrombocytopenia, grade 3 thrombocytopenia with active bleeding, OR grade 4 neutropenia has normalized to grade 2 or lower (or baseline), then restart treatment at 100 mg/day below the last given dose. Fedratinib dose reductions should be considered in patients who become dependent on red blood cell transfusions. CBC counts should be monitored at baseline and every 3 months thereafter; treatment should be modified based on PLT levels and active bleeding. Caution is recommended in patients who may be at increased risk.

It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.

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.

Adverse hematologic effects including neutropenia, thrombocytopenia, and anemia have been associated with the use of fedratinib. It is recommended to modify the starting dose in patients with a baseline platelet count (PLT) less than 50 x 10(9)/L. Therapy should be interrupted until grade 4 thrombocytopenia, grade 3 thrombocytopenia with active bleeding, OR grade 4 neutropenia has normalized to grade 2 or lower (or baseline), then restart treatment at 100 mg/day below the last given dose. Fedratinib dose reductions should be considered in patients who become dependent on red blood cell transfusions. CBC counts should be monitored at baseline and every 3 months thereafter; treatment should be modified based on PLT levels and active bleeding. Caution is recommended in patients who may be at increased risk.

Adverse hematologic effects including neutropenia, thrombocytopenia, and anemia have been associated with the use of fedratinib. It is recommended to modify the starting dose in patients with a baseline platelet count (PLT) less than 50 x 10(9)/L. Therapy should be interrupted until grade 4 thrombocytopenia, grade 3 thrombocytopenia with active bleeding, OR grade 4 neutropenia has normalized to grade 2 or lower (or baseline), then restart treatment at 100 mg/day below the last given dose. Fedratinib dose reductions should be considered in patients who become dependent on red blood cell transfusions. CBC counts should be monitored at baseline and every 3 months thereafter; treatment should be modified based on PLT levels and active bleeding. Caution is recommended in patients who may be at increased risk.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.

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.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

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.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.

Pancreatitis occurred in patients receiving fedratinib. It is recommended to monitor lipase and amylase prior to the start of therapy with fedratinib and periodically thereafter as clinically indicated. Therapy should be interrupted until grade 3 or higher elevations in amylase and/or lipase levels resolve to grade 1 or less (or baseline), then restart treatment at 100 mg/day below the last given dose. Care is recommended when using this agent in patients at risk.

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.

Due to potential increase of exposure, patients with preexisting-existing moderate renal impairment require more intensive safety monitoring, and if necessary, dose modifications based on adverse reactions when treated with fedratinib. Reduce fedratinib dose when administered to patients with severe renal impairment (CrCl 15 mL/min to 29 mL/min by Cockcroft-Gault). No modification of the starting dose is recommended for patients with mild to moderate renal impairment (CrCl 30 mL/min to 89 mL/min by Cockcroft-Gault).

Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.