24Hr Allergy-Congestion Relief

Drug overview for 24HR ALLERGY-CONGESTION RELIEF (fexofenadine hcl/pseudoephedrine hcl):

Generic name: fexofenadine HCl/pseudoephedrine HCl (fex-oh-FEN-uh-deen/sue-doh-eff-ED-rin)
Drug class: Amphetamines/Anorexiants/Stimulants
Therapeutic class: Respiratory Therapy Agents

Fexofenadine, a second-generation antihistamine, is the active carboxylic Pseudoephedrine is a sympathomimetic agent that occurs naturally in plants acid metabolite of terfenadine. of the genus Ephedra; the drug acts directly on both alpha- and, to a lesser degree, beta-adrenergic receptors.

Fexofenadine shares the uses of other antihistamines, including the Pseudoephedrine is used as a nasal decongestant for self-medication for the management of allergic rhinitis and chronic idiopathic urticaria. For temporary relief of nasal congestion associated with upper respiratory additional information on these and other uses of antihistamines,see Uses allergy and to provide temporary relief of sinus congestion and pressure. in the Antihistamines General Statement 4:00.

The drug also has been used for self-medication in the symptomatic prevention of otitic barotrauma+ (aerotitis ( barotitis) media). Fexofenadine is the active carboxylic acid metabolite of terfenadine (no Pseudoephedrine also has been misused for clandestine synthesis of longer commercially available in the US). Fexofenadine is thought to methamphetamine and methcathinone for illicit use.

provide essentially all the therapeutic benefits of terfenadine while avoiding the serious cardiotoxic and drug interaction risks of the parent drug, and therefore is considered a relatively safe alternative to terfenadine. Although other relatively nonsedating (second generation) antihistamines that lack the cardiotoxic and drug interaction potentials of terfenadine also are commercially available in the US, individual patients vary in their response to antihistamines, and a specific antihistamine that provides dramatic relief without adverse effects to one patient may be ineffective or poorly tolerated in another. Trial of various antihistamines may be necessary to determine which drug will cause relief while causing minimal adverse effects.

DRUG IMAGES

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The following indications for 24HR ALLERGY-CONGESTION RELIEF (fexofenadine hcl/pseudoephedrine hcl) have been approved by the FDA:

Indications:
Allergic conjunctivitis
Allergic rhinitis
Sneezing

Professional Synonyms:
Allergy eye itch
Atopic conjunctivitis
Itchy eyes due to allergies
Ocular itching due to allergies

The following dosing information is available for 24HR ALLERGY-CONGESTION RELIEF (fexofenadine hcl/pseudoephedrine hcl):

Dosing
Administration
24HR ALLERGY-CONGESTION RELIEF
FEXOFENADINE-PSE ER

Adjustment of fexofenadine hydrochloride dosage may be necessary in patients with renal impairment. Peak plasma fexofenadine concentrations increased by 87 or 111%, and elimination half-life increased by 59 or 72% in patients with mild (e.g., creatinine clearance of 41-80 mL/minute) or severe (creatinine clearance of 11-40 mL/minute) renal impairment, respectively, when compared with those observed in healthy individuals. In addition, peak plasma fexofenadine concentration increased by 82% and elimination half-life increased by 31% in those on hemodialysis (creatinine clearance of 10 mL/minute or less) compared with healthy individuals.

The manufacturer states that adults and children 12 years of age and older with impaired renal function or those on hemodialysis should receive an initial fexofenadine hydrochloride dosage of 60 mg daily (either given alone or in fixed combination with 120 mg of pseudoephedrine hydrochloride (Allegra-D(R) 12 Hour)). The fixed-combination preparation containing 180 mg of fexofenadine hydrochloride and 240 mg of pseudoephedrine hydrochloride (Allegra-D(R) 24 Hour) generally should be avoided in patients with renal impairment because of a possible risk of accumulation of pseudoephedrine.

Children 6 to younger than 12 years of age with impaired renal function should receive an initial fexofenadine hydrochloride dosage of 30 mg daily.

Since the pharmacokinetics of fexofenadine do not appear to be altered in patients with hepatic impairment, the manufacturer states that dosage adjustment is not necessary in such patients. The manufacturer of Allegra-D(R) 12 Hour and Allegra-D(R) 24 Hour does not make specific recommendations for dosage adjustment in patients with hepatic impairment, although it is not known if pharmacokinetics of pseudoephedrine are altered in patients with hepatic impairment.

Fexofenadine hydrochloride is administered orally. The manufacturer states Pseudoephedrine hydrochloride and sulfate are administered orally. that when fexofenadine hydrochloride is given alone (i.e., not in fixed combination with pseudoephedrine hydrochloride) the drug may be given Pseudoephedrine hydrochloride 240-mg extended-release tablets should be administered orally once daily and swallowed whole with water; the without regard to meals.

Since absorption and peak plasma concentrations of extended-release tablets should not be divided, crushed, chewed, or fexofenadine are decreased by concomitant administration of an aluminum and dissolved. Patients should be advised that the tablet does not completely magnesium hydroxides antacid (Maalox(R)) (see Pharmacokinetics: Absorption and see Drug Interactions: Antacids), the manufacturer recommends that the dissolve and may be passed in the stool. drug not be taken closely in time with an antacid containing aluminum and magnesium.

Since food appears to substantially affect the rate and extent of absorption of fexofenadine hydrochloride when administered as the extended-release tablets of the drug in fixed combination with pseudoephedrine hydrochloride, the manufacturer states that such extended-release tablets should be administered on an empty stomach with water. (See Pharmacokinetics: Absorption and see Drug Interactions: Fruit Juices.) Extended-release tablets containing fexofenadine hydrochloride in fixed combination with pseudoephedrine hydrochloride should be swallowed intact, and patients should be instructed not to break, crush, or chew such tablets.

Dosing information for 24HR ALLERGY-CONGESTION RELIEF
DRUG LABEL	DOSING TYPE	DOSING INSTRUCTIONS
24HR ALLERGY-CONGST 180-240 MG	Maintenance	Adults take 1 tablet by oral route once daily on an empty stomach with glass of water

Generic dosing information for FEXOFENADINE-PSE ER
DRUG LABEL	DOSING TYPE	DOSING INSTRUCTIONS
FEXOFENADINE-PSE ER 180-240 TB	Maintenance	Adults take 1 tablet by oral route once daily on an empty stomach with glassof water

The following drug interaction information is available for 24HR ALLERGY-CONGESTION RELIEF (fexofenadine hcl/pseudoephedrine hcl):

Contraindicated
Severe
Moderate

There are 1 contraindications. These drug combinations generally should not be dispensed or administered to the same patient. A manufacturer label warning that indicates the contraindication warrants inclusion of a drug combination in this category, regardless of clinical evidence or lack of clinical evidence to support the contraindication.

Drug Interaction	Drug Names
Sympathomimetics (Indirect & Mixed Acting)/MAOIs SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Catecholamine stores increased by MAOIs can be released by indirect acting sympathomimetics such as ephedrine and amphetamine. MAO inhibitors also interfere with gut and liver metabolism of direct acting sympathomimetics (e.g oral phenylephrine). CLINICAL EFFECTS: Concurrent use of MAOIs may result in potentiation of sympathomimetic effects, which may result in headaches, hypertensive crisis, toxic neurological effects, and malignant hyperpyrexia. Fatalities have occurred. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Concurrent use of monoamine oxidase inhibitors and sympathomimetics is contraindicated. The manufacturers of sympathomimetic agents recommend waiting 14 days after discontinuation of MAO inhibitors before initiating the sympathomimetic. DISCUSSION: Indirect acting sympathomimetic amines may cause abrupt elevation of blood pressure when administered to patients taking monoamine oxidase inhibitors, resulting in a potentially fatal hypertensive crisis. Mixed (direct and indirect) acting sympathomimetics have also been shown to interact with monoamine oxidase inhibitors depending on their degree of indirect action. The direct-acting sympathomimetics have not been reported to interact. Dopamine is metabolized by monoamine oxidase, and its pressor effect is enhanced by monoamine oxidase inhibitors. Since procarbazine, an antineoplastic agent, is a weak monoamine oxidase inhibitor, hypertensive reactions may result from its concurrent use with indirect and mixed acting sympathomimetics. Furazolidone, an antibacterial with monoamine oxidase inhibitor action, has also been shown to interact with indirect acting sympathomimetics. Linezolid is another antibacterial with monoamine oxidase inhibitor properties. Metaxalone is a weak inhibitor of MAO. Foods containing large amounts of tyramine have also been implicated in this interaction. Methylene blue, when administered intravenously, has been shown to reach sufficient concentrations to be a potent inhibitor of MAO-A. At recommended dosages, rasagiline, oral selegiline, and transdermal selegiline up to 6mg/day are selective for MAO-B; however, at higher dosages they have been shown to lose their selectivity. One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology.	EMSAM, FURAZOLIDONE, MARPLAN, MATULANE, METAXALONE, METHYLENE BLUE, NARDIL, PARNATE, PHENELZINE SULFATE, PROCARBAZINE HCL, PROVAYBLUE, SELEGILINE HCL, TRANYLCYPROMINE SULFATE

Drug Interaction

Drug Names

Sympathomimetics (Indirect & Mixed Acting)/MAOIs

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Catecholamine stores increased by MAOIs can be released by indirect acting sympathomimetics such as ephedrine and amphetamine. MAO inhibitors also interfere with gut and liver metabolism of direct acting sympathomimetics (e.g oral phenylephrine).

CLINICAL EFFECTS: Concurrent use of MAOIs may result in potentiation of sympathomimetic effects, which may result in headaches, hypertensive crisis, toxic neurological effects, and malignant hyperpyrexia. Fatalities have occurred.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Concurrent use of monoamine oxidase inhibitors and sympathomimetics is contraindicated. The manufacturers of sympathomimetic agents recommend waiting 14 days after discontinuation of MAO inhibitors before initiating the sympathomimetic.

DISCUSSION: Indirect acting sympathomimetic amines may cause abrupt elevation of blood pressure when administered to patients taking monoamine oxidase inhibitors, resulting in a potentially fatal hypertensive crisis. Mixed (direct and indirect) acting sympathomimetics have also been shown to interact with monoamine oxidase inhibitors depending on their degree of indirect action. The direct-acting sympathomimetics have not been reported to interact.

Dopamine is metabolized by monoamine oxidase, and its pressor effect is enhanced by monoamine oxidase inhibitors. Since procarbazine, an antineoplastic agent, is a weak monoamine oxidase inhibitor, hypertensive reactions may result from its concurrent use with indirect and mixed acting sympathomimetics. Furazolidone, an antibacterial with monoamine oxidase inhibitor action, has also been shown to interact with indirect acting sympathomimetics.

Linezolid is another antibacterial with monoamine oxidase inhibitor properties. Metaxalone is a weak inhibitor of MAO. Foods containing large amounts of tyramine have also been implicated in this interaction.

Methylene blue, when administered intravenously, has been shown to reach sufficient concentrations to be a potent inhibitor of MAO-A. At recommended dosages, rasagiline, oral selegiline, and transdermal selegiline up to 6mg/day are selective for MAO-B; however, at higher dosages they have been shown to lose their selectivity. One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems.

This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology.

EMSAM, FURAZOLIDONE, MARPLAN, MATULANE, METAXALONE, METHYLENE BLUE, NARDIL, PARNATE, PHENELZINE SULFATE, PROCARBAZINE HCL, PROVAYBLUE, SELEGILINE HCL, TRANYLCYPROMINE SULFATE

There are 6 severe interactions. These drug interactions can produce serious consequences in most patients. Actions required for severe interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration scheduling, and providing additional patient monitoring. Review the full interaction monograph for more information.

Drug Interaction	Drug Names
Ergot Alkaloids/Sympathomimetics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of ergot alkaloids and sympathomimetics may result in additive or synergistic effect on peripheral blood vessels. CLINICAL EFFECTS: Concurrent use of ergot alkaloids and sympathomimetics may result in increased blood pressure due to peripheral vasoconstriction. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: When possible, avoid the concurrent use of ergot alkaloids and sympathomimetics. If concurrent use is warranted, monitor blood pressure and for signs of vasoconstriction. Decreasing the dose of one or both drugs may be necessary. DISCUSSION: There have been reports of severe vasoconstriction resulting in gangrene in patients receiving intravenous ergonovine with dopamine or norepinephrine.	DIHYDROERGOTAMINE MESYLATE, ERGOLOID MESYLATES, ERGOMAR, ERGOTAMINE TARTRATE, ERGOTAMINE-CAFFEINE, METHYLERGONOVINE MALEATE, METHYSERGIDE MALEATE, MIGERGOT, MIGRANAL, TRUDHESA
Mixed;Indirect Sympathomimetics/Selected MAOIs SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Catecholamine stores increased by MAOIs can be released by indirect acting sympathomimetics such as ephedrine and amphetamine. MAO inhibitors also interfere with gut and liver metabolism of direct acting sympathomimetics (e.g oral phenylephrine). CLINICAL EFFECTS: Concurrent use of MAOIs may result in potentiation of sympathomimetic effects, which may result in headaches, hypertensive crisis, toxic neurological effects, and malignant hyperpyrexia. Fatalities have occurred with combinations of sympathomimetics and MAO-A inhibitors. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Concurrent use of MAO-A inhibitors and sympathomimetics is contraindicated. The manufacturers of sympathomimetic agents recommend waiting 14 days after discontinuation of MAO inhibitors before initiating the sympathomimetic. Patients receiving direct or indirect acting sympathomimetics should not receive linezolid unless they are monitored for potential increases in blood pressure. Initial dosages of dopamine and epinephrine should be reduced. At recommended dosages, oral selegiline and transdermal selegiline up to 6mg/day are selective for MAO-B; however, at higher dosages they have been shown to lose their selectivity. Patients receiving higher dosages of selegiline should be considered susceptive to this interaction. DISCUSSION: Indirect acting sympathomimetic amines may cause abrupt elevation of blood pressure when administered to patients taking monoamine oxidase inhibitors, resulting in a potentially fatal hypertensive crisis. Mixed (direct and indirect) acting sympathomimetics have also been shown to interact with monoamine oxidase inhibitors depending on their degree of indirect action. The direct-acting sympathomimetics have not been reported to interact. Dopamine is metabolized by monoamine oxidase, and its pressor effect is enhanced by monoamine oxidase inhibitors. Furazolidone, an antibacterial with monoamine oxidase inhibitor action, has also been shown to interact with indirect acting sympathomimetics. Foods containing large amounts of tyramine have also been implicated in this interaction. A significant pressor response was observed in normal subjects receiving linezolid and tyramine doses of more than 100 mg. Administration of linezolid (600 mg BID for 3 days) with pseudoephedrine (60 mg q 4 hours for 2 doses) increased blood pressure by 32 mmHg. Administration of linezolid (600 mg BID for 3 days) with phenylpropanolamine (25 mg q 4 hours for 2 doses) increased blood pressure by 38 mmHg. One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology.	EMSAM, LINEZOLID, LINEZOLID-0.9% NACL, LINEZOLID-D5W, SELEGILINE HCL, XADAGO, ZELAPAR, ZYVOX
Radioactive Iodide/Agents that Affect Iodide SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Many compounds can affect iodide protein binding and alter iodide pharmacokinetics and pharmacodynamics.(1) CLINICAL EFFECTS: Compounds that affect iodide pharmacokinetics and pharmacodynamics may impact the effectiveness of radioactive iodide.(1) PREDISPOSING FACTORS: Compounds that affect iodide pharmacokinetics and pharmacodynamics are expected to have the most impact during therapy using radioactive iodide. Diagnostic procedures would be expected to be impacted less. PATIENT MANAGEMENT: Discuss the use of agents that affect iodide pharmacokinetics and pharmacodynamics with the patient's oncologist.(1) Because indocyanine green contains sodium iodide, the iodine-binding capacity of thyroid tissue may be reduced for at least one week following administration. Do not perform radioactive iodine uptake studies for at least one week following administration of indocyanine green.(2) The manufacturer of iopamidol states administration may interfere with thyroid uptake of radioactive iodine and decrease therapeutic and diagnostic efficacy. Avoid thyroid therapy or testing for up to 6 weeks post administration of iopamidol.(3) DISCUSSION: Many agents interact with radioactive iodine. The average duration of effect is: anticoagulants - 1 week antihistamines - 1 week anti-thyroid drugs, e.g: carbimazole, methimazole, propylthiouracil - 3-5 days corticosteroids - 1 week iodide-containing medications, e.g: amiodarone - 1-6 months expectorants - 2 weeks Lugol solution - 3 weeks saturated solution of potassium iodine - 3 weeks vitamins - 10-14 days iodide-containing X-ray contrast agents - up to 1 year lithium - 4 weeks phenylbutazone - 1-2 weeks sulfonamides - 1 week thyroid hormones (natural or synthetic), e.g.: thyroxine - 4 weeks tri-iodothyronine - 2 weeks tolbutamide - 1 week topical iodide - 1-9 months (1)	ADREVIEW, JEANATOPE, MEGATOPE, SODIUM IODIDE I-123
Iobenguane I 123/Agents that Affect Catecholamines SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Many compounds that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells.(1) CLINICAL EFFECTS: Compounds that reduce catecholamine uptake or that deplete catecholamine stores may interfere with imaging completed with iobenguane.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Discuss the use of agents that affect catecholamines. Discontinue drugs that reduce catecholamine uptake or deplete catecholamine stores prior to imaging with iobenguane. Before imaging with iobenguane, discontinue agents that affect catecholamines for at least 5 biological half-lives, as clinically tolerated.(1) DISCUSSION: Many agents may reduce catecholamine uptake or deplete catecholamine stores.(1) Examples include: - CNS stimulants or amphetamines (e.g. cocaine, methylphenidate, dextroamphetamine) - norepinephrine and dopamine reuptake inhibitors (e.g. phentermine) - norepinephrine and serotonin reuptake inhibitors (e.g. tramadol) - monoamine oxidase inhibitors (e.g. phenelzine, linezolid) - central monoamine depleting drugs (e.g. reserpine) - non-select beta adrenergic blocking drugs (e.g. labetalol) - alpha agonists or alpha/beta agonists (e.g. pseudoephedrine, phenylephrine, ephedrine, phenylpropanolamine, naphazoline) - tricyclic antidepressants or norepinephrine reuptake inhibitors (e.g. amitriptyline, bupropion, duloxetine, mirtazapine, venlafaxine) - botanicals that may inhibit reuptake of norepinephrine, serotonin or dopamine (e.g. ephedra, ma huang, St. John's Wort, yohimbine)	ADREVIEW
Mixed;Indirect Sympathomimetics/Rasagiline SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Catecholamine stores increased by MAOIs can be released by indirect acting sympathomimetics such as ephedrine and amphetamine. MAO inhibitors also interfere with gut and liver metabolism of direct acting sympathomimetics (e.g oral phenylephrine). CLINICAL EFFECTS: Concurrent use of MAOIs may result in potentiation of sympathomimetic effects, which may result in headaches, hypertensive crisis, toxic neurological effects, and malignant hyperpyrexia. Hypertensive crisis has been reported in patients taking recommended doses of rasagiline with sympathomimetic agents. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: At recommended dosages, rasagiline is selective for MAO-B; however, at higher dosages it has been shown to lose its selectivity. Patients receiving higher dosages of rasagiline should be considered susceptive to this interaction. Concurrent use should be approached with caution. DISCUSSION: Indirect acting sympathomimetic amines may cause abrupt elevation of blood pressure when administered to patients taking monoamine oxidase inhibitors, resulting in a potentially fatal hypertensive crisis. Mixed (direct and indirect) acting sympathomimetics have also been shown to interact with monoamine oxidase inhibitors depending on their degree of indirect action. The direct-acting sympathomimetics have not been reported to interact. Dopamine is metabolized by monoamine oxidase, and its pressor effect is enhanced by monoamine oxidase inhibitors.	AZILECT, RASAGILINE MESYLATE
Sodium Iodide I 131/Agents that Affect Iodide SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Many compounds can affect iodide protein binding and alter iodide pharmacokinetics and pharmacodynamics.(1,2) CLINICAL EFFECTS: Compounds that affect iodide pharmacokinetics and pharmacodynamics may impact the effectiveness of radioactive iodide.(1,2) PREDISPOSING FACTORS: Compounds that affect iodide pharmacokinetics and pharmacodynamics are expected to have the most impact during therapy using radioactive iodide. Diagnostic procedures would be expected to be impacted less. PATIENT MANAGEMENT: Discuss the use of agents that affect iodide pharmacokinetics and pharmacodynamics with the patient's oncologist.(1,2) Because indocyanine green contains sodium iodide, the iodine-binding capacity of thyroid tissue may be reduced for at least one week following administration. Do not perform radioactive iodine uptake studies for at least one week following administration of indocyanine green.(3) The manufacturer of iopamidol states administration may interfere with thyroid uptake of radioactive iodine and decrease therapeutic and diagnostic efficacy. Avoid thyroid therapy or testing for up to 6 weeks post administration of iopamidol.(4) DISCUSSION: Many agents interact with radioactive iodine. The average duration of effect is: anticoagulants - 1 week antihistamines - 1 week anti-thyroid drugs, e.g: carbimazole, methimazole, propylthiouracil - 3-5 days corticosteroids - 1 week iodide-containing medications, e.g: amiodarone - 1-6 months expectorants - 2 weeks Lugol solution - 3 weeks saturated solution of potassium iodine - 3 weeks vitamins - 10-14 days iodide-containing X-ray contrast agents - up to 1 year lithium - 4 weeks phenylbutazone - 1-2 weeks sulfonamides - 1 week thyroid hormones (natural or synthetic), e.g.: thyroxine - 4 weeks tri-iodothyronine - 2 weeks tolbutamide - 1 week topical iodide - 1-9 months (1,2)	HICON, SODIUM IODIDE I-131

There are 3 moderate interactions. The clinician should assess the patient’s characteristics and take action as needed. Actions required for moderate interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration.

Drug Interaction	Drug Names
Sympathomimetics (Direct, Mixed-Acting)/Guanethidine SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Direct or mixed-acting sympathomimetics may inhibit uptake of guanethidine at the adrenergic neuron. CLINICAL EFFECTS: Decreased antihypertensive effectiveness. Effects may be seen for several days after discontinuation of the direct or mixed-acting sympathomimetic. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Avoid concomitant administration of these drugs. If both drugs are administered, adjust the guanethidine dose as needed based on blood pressure. DISCUSSION: Documentation supports routine monitoring of this interaction. It should be noted that this interaction can occur quickly.	GUANETHIDINE HEMISULFATE
Sympathomimetics/Rauwolfia Alkaloids SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Reserpine depletes catecholamine stores within the peripheral vascular adrenergic nerve endings, thus indirect acting sympathomimetics are unable to trigger the release of catecholamines. The reserpine-induced catecholamine release increases sensitivity to the effects of direct acting sympathomimetics. CLINICAL EFFECTS: Increased effects of direct acting sympathomimetics. Decreased effects of indirect acting sympathomimetics. Mixed acting sympathomimetics will show effects based on the predominance of either direct or indirect activity. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: If these agents are administered concurrently, monitor blood pressure. The dose of the sympathomimetic may need to be adjusted. DISCUSSION: This interaction has been well documented in animal studies and human case reports have confirmed the interaction. Reserpine has been shown to decrease the response to epinephrine administered for hypotension. Reserpine has also been shown to decrease the effectiveness of ophthalmic epinephrine, a direct acting sympathomimetic. Ophthalmic phenylephrine has been shown to decrease the hypotensive effects of reserpine.	RESERPINE
Sympathomimetics (Direct, Mixed-Acting)/Methyldopa SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Unknown. CLINICAL EFFECTS: The pressor response to sympathomimetics may be increased. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Start with low doses of sympathomimetics and monitor blood pressure of patients during concurrent administration of sympathomimetics and methyldopa. DISCUSSION: The pressor response to sympathomimetics has been reported to be increased during methyldopa administration. In addition to increased duration of pressor response, severe hypertension has been reported.	METHYLDOPA, METHYLDOPA-HYDROCHLOROTHIAZIDE, METHYLDOPATE HCL

The following contraindication information is available for 24HR ALLERGY-CONGESTION RELIEF (fexofenadine hcl/pseudoephedrine hcl):

Overview
Contraindicated
Severe
Moderate

Drug contraindication overview.

No enhanced Contraindications information available for this drug.

There are 3 contraindications. Absolute contraindication.

Contraindication List
Severe coronary artery disease
Severe uncontrolled hypertension
Urinary retention

There are 6 severe contraindications. Adequate patient monitoring is recommended for safer drug use.

Severe List
Angle-closure glaucoma
Benign prostatic hyperplasia
Diabetes mellitus
Hypertension
Hyperthyroidism
Pheochromocytoma

There are 2 moderate contraindications. Clinically significant contraindication, where the condition can be managed or treated before the drug may be given safely.

Moderate List
Kidney disease with reduction in glomerular filtration rate (GFr)
Severe hepatic disease

The following adverse reaction information is available for 24HR ALLERGY-CONGESTION RELIEF (fexofenadine hcl/pseudoephedrine hcl):

Overview
Severe
Less Severe

Adverse reaction overview.

No enhanced Common Adverse Effects information available for this drug.

There are 14 severe adverse reactions.

More Frequent	Less Frequent
None.	None.

Rare/Very Rare
Acute bacterial otitis media Acute generalized exanthematous pustulosis Anaphylaxis Dyspnea Hallucinations Hypersensitivity drug reaction Hypertension Ischemic colitis Posterior reversible encephalopathy syndrome Reversible cerebral vasoconstriction syndrome Seizure disorder Upper respiratory infection Urticaria Vomiting

There are 44 less severe adverse reactions.

More Frequent	Less Frequent
Headache disorder Insomnia	Agitation Anorexia Back pain Dizziness Drowsy Dysmenorrhea Dyspepsia Dysuria Fatigue General weakness Headache disorder Myalgia Nausea Nervousness Pallor Pharyngitis Sinusitis Skin rash Tachycardia Tremor Viral infection Vomiting Xerostomia

Rare/Very Rare
Abdominal pain with cramps Agitation Blurred vision Cardiac arrhythmia Chest tightness Cough Dyspepsia Earache Excitement Fever Hyperhidrosis Insomnia Nervousness Nightmares Pain Palpitations Pruritus of skin Symptoms of anxiety Syncope

The following precautions are available for 24HR ALLERGY-CONGESTION RELIEF (fexofenadine hcl/pseudoephedrine hcl):

Pediatric
Pregnant
Lactation
Geriatric

No enhanced Pediatric Use information available for this drug.

Contraindicated

None

Severe Precaution

None

Management or Monitoring Precaution

None

Reproduction studies in mice receiving fexofenadine doses up to 3730 mg/kg (approximately 10-15 times the maximum recommended daily oral human dosage of fexofenadine hydrochloride in adults) have not revealed evidence of adverse or teratogenic effects during gestation. Reproduction studies in rats and rabbits using oral terfenadine dosages up to 300 mg/kg resulting in fexofenadine exposure levels calculated to be about 3-4 and 25-31 times, respectively, those resulting from the maximum recommended daily oral human dosage of fexofenadine hydrochloride in adults have not revealed evidence of teratogenicity. However, in rats, oral terfenadine dosages of 150 mg/kg, resulting in fexofenadine exposure levels calculated to be about 3-4 times those resulting from the maximum recommended daily oral human dosage of fexofenadine hydrochloride in adults (based on comparison of the AUC), were associated with decreased weight gain and neonatal survival in the pups.

Reproduction studies in rats and rabbits using terfenadine and pseudoephedrine hydrochloride in a fixed-combination ratio of 1:2 at dosages of 150/300 (corresponding to fexofenadine AUCs of about 3-4 times the maximum recommended adult therapeutic value and to pseudoephedrine hydrochloride dosages about 10 times the maximum recommended human adult daily oral dosage, on a mg/m2 basis) and 100/200 mg/kg daily (corresponding to fexofenadine AUCs of about 8-10 times the maximum recommended adult therapeutic value and to pseudoephedrine hydrochloride dosages about 15 times the maximum recommended human adult daily oral dosage, on a mg/m2 basis), respectively, have revealed evidence of reduced fetal weight; delayed ossification with wavy ribs also was observed in rats receiving the drug at these dosages. There are no adequate and controlled studies to date using fexofenadine in pregnant women, and fexofenadine hydrochloride alone or in fixed combination with pseudoephedrine hydrochloride should be used during pregnancy only when the potential benefits justify the possible risks to the fetus.

It is not known if fexofenadine hydrochloride is distributed into breast milk; however, pseudoephedrine hydrochloride distributes into breast milk. Since there are no adequate and controlled studies to date on the use of fexofenadine during lactation in humans and because many drugs are excreted in human milk, the manufacturer states that fexofenadine alone or in fixed combination with pseudoephedrine hydrochloride should be used with caution in nursing women, and a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the woman.

No enhanced Geriatric Use information available for this drug.

The following icd codes are available for 24HR ALLERGY-CONGESTION RELIEF (fexofenadine hcl/pseudoephedrine hcl)'s list of indications:

Allergic conjunctivitis
H10.1	Acute atopic conjunctivitis
H10.10	Acute atopic conjunctivitis, unspecified eye
H10.11	Acute atopic conjunctivitis, right eye
H10.12	Acute atopic conjunctivitis, left eye
H10.13	Acute atopic conjunctivitis, bilateral
H10.44	Vernal conjunctivitis
H10.45	Other chronic allergic conjunctivitis
H16.26	Vernal keratoconjunctivitis, with limbar and corneal involvement
H16.261	Vernal keratoconjunctivitis, with limbar and corneal involvement, right eye
H16.262	Vernal keratoconjunctivitis, with limbar and corneal involvement, left eye
H16.263	Vernal keratoconjunctivitis, with limbar and corneal involvement, bilateral
H16.269	Vernal keratoconjunctivitis, with limbar and corneal involvement, unspecified eye
Allergic rhinitis
J30.1	Allergic rhinitis due to pollen
J30.2	Other seasonal allergic rhinitis
J30.5	Allergic rhinitis due to food
J30.8	Other allergic rhinitis
J30.81	Allergic rhinitis due to animal (cat) (dog) hair and dander
J30.89	Other allergic rhinitis
J30.9	Allergic rhinitis, unspecified
Sneezing
R06.7	Sneezing