Home Drug Guide Fexofenadine Hydrochloride and Pseudoephedrine Hydrochloride

Drug Guide

Generic Name

Fexofenadine Hydrochloride and Pseudoephedrine Hydrochloride

Brand Names Allegra-D 12 Hour Allergy and Congestion, Allegra-D 24 Hour Allergy and Congestion, Fexofenadine HCl; Pseudoephedrine HCl

Classification

Therapeutic: Antihistamine, Decongestant combination

Pharmacological: Antihistamine (selective) and Sympathomimetic decongestant

FDA Approved Indications

Relief of allergy symptoms including nasal congestion, sneezing, runny nose, and itchy eyes due to seasonal allergic rhinitis.
Relief of nasal congestion associated with allergic rhinitis.

Mechanism of Action

Fexofenadine is a selective peripheral H1 antihistamine that inhibits the effects of histamine at H1 receptor sites. Pseudoephedrine is a sympathomimetic agent that stimulates alpha-adrenergic receptors in the nasal mucosa, resulting in vasoconstriction and decreased nasal congestion.

Dosage and Administration

Adult: Typically, 60 mg twice daily or as prescribed. For 12-hour formulations: 60 mg twice a day. For 24-hour formulations: once daily 180 mg.

Pediatric: Safety and efficacy not established for children under 12; consult specific product label.

Geriatric: Adjust dosage if needed; no specific changes recommended but monitor for anticholinergic and cardiovascular effects.

Renal Impairment: Reduce dose in patients with severe renal impairment; consult dosing guidelines.

Hepatic Impairment: No specific adjustment recommended, but caution advised.

Pharmacokinetics

Absorption: Fexofenadine is well absorbed; pseudoephedrine is also rapidly absorbed.

Distribution: Fexofenadine binds extensively to plasma proteins; pseudoephedrine has minimal plasma protein binding.

Metabolism: Fexofenadine undergoes minimal metabolism; pseudoephedrine is primarily excreted unchanged.

Excretion: Excreted mainly in feces (fexofenadine) and urine (pseudoephedrine).

Half Life: Fexofenadine: approximately 14 hours; Pseudoephedrine: approximately 4-6 hours.

Contraindications

Known hypersensitivity to any components.
Use caution in patients with hypertension or cardiovascular disease (pseudoephedrine).

Precautions

Use with caution in patients with hyperthyroidism, glaucoma, and prostatic hypertrophy.
Avoid in patients taking monoamine oxidase inhibitors (MAOIs).

Adverse Reactions - Common

Headache (Common)
Nausea (Common)
Nervousness or restlessness (Common)

Adverse Reactions - Serious

Hypertension or arrhythmias (pseudoephedrine) (Serious but less common)
Allergic reactions, angioedema (rare) (Rare)

Drug-Drug Interactions

Concurrent use with other vasoconstrictors or monoamine oxidase inhibitors (MAOIs).

Drug-Food Interactions

Avoid alcohol, which can increase sedation.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, especially in hypertensive patients. Observe for allergic reactions and CNS effects.

Diagnoses:

Risk for hypertension or cardiovascular effects.
Ineffective airway clearance due to nasal congestion.

Implementation: Administer with water, caution against alcohol and CNS depressants.

Evaluation: Assess relief of allergy and congestion symptoms after administration.

Patient/Family Teaching

Take medication as prescribed. Do not exceed recommended doses.
Report any signs of increased blood pressure or allergic reactions.
Avoid alcohol and activities requiring alertness if sedated.

Special Considerations

Black Box Warnings:

Pseudoephedrine may increase blood pressure; use with caution in hypertensive patients.

Genetic Factors: None specific.

Lab Test Interference: None known.

Overdose Management

Signs/Symptoms: Excessive stimulation, hypertension, CNS excitation, nausea, vomiting.

Treatment: Supportive care; monitor cardiac status; activated charcoal may be administered if ingestion is recent.

Storage and Handling

Storage: Store at room temperature, 20-25°C (68-77°F).

Stability: Stable if stored properly; protect from moisture and light.