Levocetirizine + Pseudoephedrine

Usage

Levocetirizine + Pseudoephedrine is prescribed for the symptomatic relief of allergic rhinitis (hay fever) and the common cold. It effectively addresses symptoms like sneezing, runny nose, nasal congestion, itchy or watery eyes, and sinus pressure.

• Pharmacological Classification: This combination drug falls under two classifications:

  • Levocetirizine: Antihistamine (specifically, a second-generation non-sedating antihistamine).
  • Pseudoephedrine: Decongestant (specifically, a sympathomimetic amine).

• Mechanism of Action: Levocetirizine competes with histamine for binding to H1-receptor sites, thus reducing the effects of histamine, a chemical mediator responsible for allergic symptoms. Pseudoephedrine acts as an alpha-adrenergic agonist, constricting blood vessels in the nasal mucosa, which reduces nasal congestion.

Alternate Names

While “Levocetirizine + Pseudoephedrine” is the standard generic name, some regional variations may exist. Several brand names are available depending on the manufacturer and country. A few examples of brand names containing this drug combination include Xyzal Allergy 24HR.

How It Works

• Pharmacodynamics: Levocetirizine antagonizes the effects of histamine at peripheral H1 receptors, reducing vascular permeability and the formation of edema, thereby alleviating allergic symptoms. Pseudoephedrine, through its alpha-adrenergic agonist activity, constricts dilated blood vessels in the nasal mucosa, reducing nasal congestion.

• Pharmacokinetics:

  • Absorption: Both drugs are well-absorbed after oral administration.
  • Metabolism: Levocetirizine undergoes minimal metabolism. Pseudoephedrine is partially metabolized in the liver.
  • Elimination: Levocetirizine is primarily excreted unchanged in the urine. Pseudoephedrine is excreted primarily in the urine, both unchanged and as metabolites.

• Mode of Action (Cellular/Molecular): Levocetirizine selectively binds to peripheral H1 receptors without significant anticholinergic or serotonergic activity. Pseudoephedrine stimulates alpha-adrenergic receptors in the nasal vasculature, leading to vasoconstriction.

• Receptor Binding, Enzyme Inhibition, Neurotransmitter Modulation: Levocetirizine acts as a competitive antagonist at the H1 receptor. Pseudoephedrine indirectly affects neurotransmitter release by influencing presynaptic adrenergic receptors.

Dosage

Standard Dosage

Adults and Children 12 years and older:

• One tablet (typically containing 5mg levocetirizine and 120mg pseudoephedrine) every 12 hours.
• Maximum dose: Two tablets per 24 hours.

Children:

• Children under 12 years: Not recommended due to the pseudoephedrine component.

Special Cases:

• Elderly Patients: Use with caution; dose adjustments may be necessary based on kidney function.
• Patients with Renal Impairment: Dose adjustment is crucial, depending on creatinine clearance (CrCl). (See Dosage Modifications section for more details).
• Patients with Hepatic Dysfunction: Dose adjustment may be necessary based on the severity of liver disease.
• Patients with Comorbid Conditions: Caution should be exercised in patients with hypertension, diabetes mellitus, hyperthyroidism, elevated intraocular pressure, prostatic hypertrophy, cardiovascular disease, or other relevant conditions.

Clinical Use Cases

The primary clinical use case for this combination is the relief of symptoms associated with allergic rhinitis and the common cold. It is not typically indicated for use in settings like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations.

Dosage Adjustments

As of 2025-02-16, for adults: CrCl 50-80 mL/min: 2.5 mg PO qDay CrCl 30-50 mL/min: 2.5 mg PO every other day CrCl 10-30 mL/min: 2.5 mg PO 2x/wk (i.e., q3-4 days) CrCl <10 mL/min and/or hemodialysis: Contraindicated

Children 6 months to <12 years with any degree of renal impairment: Contraindicated.

Side Effects

Common Side Effects:

• Dry mouth
• Headache
• Fatigue
• Drowsiness
• Dizziness
• Nausea
• Vomiting
• Diarrhea
• Constipation
• Insomnia

Rare but Serious Side Effects:

• Allergic reactions (rash, itching, swelling, severe dizziness, difficulty breathing)
• Tachycardia
• Palpitations
• Hypertension
• Hallucinations
• Seizures

Long-Term Effects:

Limited data is available on the long-term effects. However, prolonged use of pseudoephedrine can lead to tolerance and rebound congestion.

Adverse Drug Reactions (ADR):

Any severe or unusual reaction should be considered a potential ADR and reported accordingly.

Contraindications

• Hypersensitivity to levocetirizine, cetirizine, pseudoephedrine, or any component of the formulation.
• Narrow-angle glaucoma
• Urinary retention
• Severe hypertension
• Severe coronary artery disease
• Within 14 days of MAO inhibitor use
• End-stage renal disease
• Patients on dialysis

Drug Interactions

• MAO inhibitors: Concomitant use is contraindicated.
• Other sympathomimetic amines: Can potentiate the effects of pseudoephedrine, increasing the risk of adverse effects.
• Antihistamines: May increase sedative effects.
• Alcohol: May increase drowsiness and dizziness.
• Tricyclic antidepressants: May potentiate the cardiovascular effects of pseudoephedrine.
• Beta-blockers: May interact with pseudoephedrine, potentially leading to hypertension.

Pregnancy and Breastfeeding

• Pregnancy: Use only if clearly needed. Consult a doctor before use.
• Breastfeeding: Levocetirizine is excreted in breast milk. Pseudoephedrine can reduce milk supply. Caution is advised. Consult a doctor before use.

Drug Profile Summary

• Mechanism of Action: Levocetirizine: H1 receptor antagonist; Pseudoephedrine: Alpha-adrenergic agonist.
• Side Effects: Dry mouth, headache, fatigue, drowsiness, dizziness, nausea, vomiting. Rarely: allergic reactions, cardiovascular effects, CNS effects.
• Contraindications: Hypersensitivity, narrow-angle glaucoma, urinary retention, severe hypertension/coronary artery disease, recent MAO inhibitor use, end-stage renal disease.
• Drug Interactions: MAO inhibitors, other sympathomimetics, alcohol, tricyclic antidepressants, beta-blockers.
• Pregnancy & Breastfeeding: Use with caution; consult a doctor.
• Dosage: Adults and children ≥12 years: One tablet every 12 hours; maximum two tablets/24 hours. Children <12 years: Not recommended.
• Monitoring Parameters: Blood pressure, heart rate, renal function, liver function (if applicable).

Popular Combinations

Levocetirizine and pseudoephedrine are often combined due to their synergistic effects in relieving allergy and cold symptoms. Sometimes ambroxol (mucolytic) or paracetamol/acetaminophen (analgesic/antipyretic) are also added to these combinations.

Precautions

• General Precautions: Evaluate for contraindications and potential drug interactions before prescribing. Monitor for adverse effects.
• Specific Populations: See “Dosage - Special Cases” and “Pregnancy and Breastfeeding.”
• Lifestyle Considerations: Avoid alcohol, as it may exacerbate drowsiness. Caution when driving or operating machinery.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Levocetirizine + Pseudoephedrine?

A: For adults and children 12 years and older, one tablet every 12 hours, not exceeding two tablets in 24 hours. Not recommended for children under 12.

Q2: Can pregnant or breastfeeding women take this medication?

A: Consult a physician before using during pregnancy or breastfeeding, as both levocetirizine and pseudoephedrine are potentially risky.

Q3: What are the common side effects?

A: Dry mouth, headache, fatigue, drowsiness, dizziness are common.

Q4: What are the serious side effects I should watch out for?

A: Allergic reactions, changes in heart rate or blood pressure, and central nervous system effects like hallucinations are potentially serious and require immediate medical attention.

Q5: What should I do if a patient experiences side effects?

A: Assess the severity of the side effects. For mild effects, supportive care may be sufficient. Discontinue the medication if side effects are intolerable or if serious side effects occur. Consult with a specialist if needed.

Q6: Does this medication interact with other medications?

A: Yes, it can interact with MAO inhibitors, other sympathomimetics, certain antidepressants, and alcohol. Always obtain a complete medication history before prescribing.

Q7: Can this medication be used in patients with renal or hepatic impairment?

A: Caution and dose adjustments are necessary in patients with renal or hepatic impairment. It is contraindicated in severe renal impairment or end-stage renal disease.

Q8: What are the contraindications for using this drug?

A: Contraindications include hypersensitivity to the components, narrow-angle glaucoma, urinary retention, severe hypertension or coronary artery disease, recent MAO inhibitor use, and severe renal impairment.

Q9: How does Levocetirizine + Pseudoephedrine differ from Cetirizine + Pseudoephedrine?

A: Levocetirizine is the active enantiomer of cetirizine. Levocetirizine + Pseudoephedrine offers similar efficacy with potentially fewer side effects, especially drowsiness, compared to the cetirizine combination.