Drug Interactions between chlorpheniramine / guaifenesin / phenylephrine and sibutramine

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.

Using sibutramine with alcohol can increase the risk of cardiovascular side effects such as increased heart rate, chest pain, or blood pressure changes. In addition, you may also be more likely to experience nervous system side effects such as dizziness, drowsiness, depression, and difficulty concentrating. You should avoid or limit the use of alcohol while being treated with sibutramine. Do not use more than the recommended dose of sibutramine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication 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.

The use of sibutramine is contraindicated in patients with anorexia nervosa. Sibutramine is an anorexiant used in the treatment of obesity.

Sibutramine and its metabolites inhibit the reuptake of norepinephrine, serotonin, and dopamine and can induce substantial increases in heart rate and blood pressure in some patients. Sibutramine therapy should not be initiated in patients with uncontrolled or poorly controlled hypertension and/or a history of coronary artery disease, arrhythmias, congestive heart failure, stroke, or other severe cardiovascular or cerebrovascular disorders. All patients treated with sibutramine should have blood pressure and pulse measured prior to starting therapy and monitored at regular intervals thereafter. Sustained increases in blood pressure or pulse rate may require a dosage reduction or drug discontinuation.

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.

Sibutramine and its metabolites inhibit the reuptake of norepinephrine, serotonin, and dopamine and can induce substantial increases in heart rate and blood pressure in some patients. Sibutramine therapy should not be initiated in patients with uncontrolled or poorly controlled hypertension and/or a history of coronary artery disease, arrhythmias, congestive heart failure, stroke, or other severe cardiovascular or cerebrovascular disorders. All patients treated with sibutramine should have blood pressure and pulse measured prior to starting therapy and monitored at regular intervals thereafter. Sustained increases in blood pressure or pulse rate may require a dosage reduction or drug discontinuation.

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.

Sibutramine and its metabolites inhibit the reuptake of norepinephrine, serotonin, and dopamine and can induce mydriasis. In patients with narrow angles, pupillary dilation can provoke an acute attack of angle-closure glaucoma. Therapy with sibutramine should be administered cautiously in patients with narrow-angle glaucoma or anatomically narrow angles.

Sibutramine and its metabolites inhibit the reuptake of norepinephrine, serotonin, and dopamine and can induce substantial increases in heart rate and blood pressure in some patients. Sibutramine therapy should not be initiated in patients with uncontrolled or poorly controlled hypertension and/or a history of coronary artery disease, arrhythmias, congestive heart failure, stroke, or other severe cardiovascular or cerebrovascular disorders. All patients treated with sibutramine should have blood pressure and pulse measured prior to starting therapy and monitored at regular intervals thereafter. Sustained increases in blood pressure or pulse rate may require a dosage reduction or drug discontinuation.

Sibutramine and its metabolites inhibit the reuptake of norepinephrine, serotonin, and dopamine and can induce substantial increases in heart rate and blood pressure in some patients. Sibutramine therapy should not be initiated in patients with uncontrolled or poorly controlled hypertension and/or a history of coronary artery disease, arrhythmias, congestive heart failure, stroke, or other severe cardiovascular or cerebrovascular disorders. All patients treated with sibutramine should have blood pressure and pulse measured prior to starting therapy and monitored at regular intervals thereafter. Sustained increases in blood pressure or pulse rate may require a dosage reduction or drug discontinuation.

Sibutramine and its metabolites inhibit the reuptake of norepinephrine, serotonin, and dopamine and can induce substantial increases in heart rate and blood pressure in some patients. Sibutramine therapy should not be initiated in patients with uncontrolled or poorly controlled hypertension and/or a history of coronary artery disease, arrhythmias, congestive heart failure, stroke, or other severe cardiovascular or cerebrovascular disorders. All patients treated with sibutramine should have blood pressure and pulse measured prior to starting therapy and monitored at regular intervals thereafter. Sustained increases in blood pressure or pulse rate may require a dosage reduction or drug discontinuation.

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.

Sibutramine is converted by the liver to two active metabolites, which are further metabolized to inactive substances and subsequently eliminated by the kidney. Due to a lack of clinical data, the manufacturer does not recommend the use of sibutramine in patients with severe renal and/or hepatic impairment. Based on limited pharmacokinetic data, sibutramine may be administered in mild or moderate hepatic insufficiency at normally recommended dosages.

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.

Sibutramine is converted by the liver to two active metabolites, which are further metabolized to inactive substances and subsequently eliminated by the kidney. Due to a lack of clinical data, the manufacturer does not recommend the use of sibutramine in patients with severe renal and/or hepatic impairment. Based on limited pharmacokinetic data, sibutramine may be administered in mild or moderate hepatic insufficiency at normally recommended dosages.

Centrally-acting anorexiants are generally subject to habituation and abuse. While sibutramine does not appear to have a significant potential for abuse, clinical data are limited. Therapy with sibutramine should be administered cautiously in patients with a history of alcohol or substance abuse. Such patients should be observed carefully during therapy for signs of misuse of sibutramine.

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.

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.

Obese, type 2 diabetic patients who achieve weight loss may demonstrate improved metabolic control of their disease as a result of their reduced weight. Therefore, patients with type 2 diabetes mellitus should be monitored during weight-reduction therapy (or therapy that may be expected to induce significant weight loss as a secondary effect) for hypoglycemia and reduced need for oral hypoglycemic medication or insulin, and the dosages of these agents adjusted accordingly. Patients should be apprised of the risk of hypoglycemia and be alert to potential signs and symptoms such as headache, dizziness, drowsiness, nervousness, confusion, tremor, hunger, weakness, perspiration, and palpitation.

Centrally-acting anorexiants are generally subject to habituation and abuse. While sibutramine does not appear to have a significant potential for abuse, clinical data are limited. Therapy with sibutramine should be administered cautiously in patients with a history of alcohol or substance abuse. Such patients should be observed carefully during therapy for signs of misuse of sibutramine.

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 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 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.

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.

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.

Sibutramine and its metabolites inhibit the reuptake of norepinephrine, serotonin, and dopamine. In clinical trials, seizures were reported in < 0.1% of patients treated with sibutramine. Therapy with sibutramine should be administered cautiously in patients with or predisposed to seizures.

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.