Quick Facts

• Targeted Use: Relief of symptoms associated with seasonal allergic rhinitis.
• Skin Applications: Management of uncomplicated skin manifestations related to chronic idiopathic urticaria (hives).

---

Allegra (fexofenadine hydrochloride) is medically recognized for providing relief from symptoms resulting from specific allergic conditions. This medication helps manage the discomfort associated with seasonal allergic rhinitis, commonly known as hay fever. Individuals may find it assists with the reduction of sneezing, runny nose, itchy or watery eyes, and itching of the nose or throat.

Furthermore, this formulation is indicated for the treatment of uncomplicated skin manifestations of chronic idiopathic urticaria, a condition characterized by hives. The medication works to address the associated skin itching and the appearance of the hives.

In both approved therapeutic domains, Allegra is a treatment option that may help control the symptoms but does not offer a cure for the underlying condition.

Eligibility for Allegra 120 (Fexofenadine 120 mg)

The official population eligibility for Allegra 120 tablets is defined by regulatory guidelines concerning age, pre-existing health conditions, and physiological status.

Eligibility Summary

Classification	Population Group	Regulatory Status
Allowed Use	Adults and adolescents ge 12 years of age	Eligible
Contraindicated	Patients with known hypersensitivity to Fexofenadine Hydrochloride or any tablet component	Prohibited
Conditional Use	Patients with renal impairment (kidney) or hepatic impairment (liver)	Requires Caution
Conditional Use	Patients with a history of or ongoing cardiovascular disease	Requires Caution
Not Recommended	Children under 12 years of age	Safety/Efficacy Not Established
Not Recommended	Lactating (breastfeeding) women	Use Not Recommended
Conditional Use	Pregnant women	Use Only If Clearly Necessary

The medicine is contraindicated for any individual with a known allergy to the active ingredient or the excipients. The 120 mg tablet formulation is approved for use in adults and adolescents aged 12 years and older. Use in younger children is not recommended as safety and efficacy have not been formally established for this tablet strength. Restricted use with caution is required for patients with decreased renal function or hepatic impairment, and for those with pre-existing cardiovascular disease.

Interactions with other medicines and products

Fexofenadine (Allegra 120) exhibits a focused interaction profile, primarily involving drug transporters and gastrointestinal binding, as officially documented in regulatory sources.

Documented Interaction Patterns

Interacting Substance	Official Interaction Outcome	Timing / Administration Rule
Erythromycin and Ketoconazole	Co-administration leads to a significant two- to three-fold increase in Fexofenadine plasma concentration, related to P-glycoprotein (P-gp) inhibition.	No mandatory timing rule stated; increased exposure is documented.
Aluminum and Magnesium Hydroxide Antacids	These substances reduce Fexofenadine bioavailability and systemic exposure due to binding in the gastrointestinal tract.	Must be administered at least 2 hours apart from Fexofenadine.
Fruit Juices (Grapefruit, Orange, Apple)	May reduce bioavailability and systemic exposure by inhibiting intestinal OATP and P-gp transporters.	Administration should be separated; do not take the medicine with fruit juices.

Official Regulatory Notes

The regulatory profile confirms that Fexofenadine undergoes negligible hepatic metabolism, meaning it is not expected to interact through the Cytochrome P450 (CYP) enzyme system. Furthermore, the medicine does not appear to potentiate the central nervous system (CNS) effects of alcohol. In patients with renal impairment, clearance is decreased, resulting in increased systemic exposure, necessitating cautious administration.

Mechanism of Action: Allegra 120

Allegra 120 (fexofenadine) exerts its effect as a selective inverse agonist at the peripheral Histamine H1 receptors (H1R). This molecular interaction locks the receptor into an inactive conformation, thereby preventing the body's endogenous histamine from binding and activating the H1 R on target cells.

This blockade interrupts the initial phase of the H1 R-mediated inflammatory signal transduction pathway. At the physiological level, this cascade modification influences peripheral outcomes, specifically the alteration of microvascular permeability and the suppression of afferent sensory nerve stimulation.

Fexofenadine's mechanism is characterized by a high degree of peripheral selectivity; due to its role as a substrate for the P-glycoprotein efflux pump, the drug is actively transported out of the central nervous system (CNS). This limited ability to cross the blood-brain barrier dictates that the resulting physiological adjustments do not involve substantial interaction with central arousal systems.

How to Use Allegra 120

The general principles for using fexofenadine tablets relate to proper administration and dosing. The medicine is designated for oral administration as a film-coated tablet, designed for systemic absorption after swallowing. The standard dosing pattern for adults and adolescents (12 years and older) is once daily (q.d.), which provides continuous coverage over a 24-hour period.

---

Administration Guidelines

Instruction	Detail
Route of Administration	Oral. The tablet must be swallowed whole.
Standard Dose for SAR	120 mg of fexofenadine hydrochloride is the usual single dose for Seasonal Allergic Rhinitis (SAR).
Standard Dose for CIU	180 mg is the commonly recognized single daily dose for Chronic Idiopathic Urticaria (CIU).
Frequency	Once daily (q.d.).
Required Liquid	The tablet must be taken with water.
Administration Restriction	Administration with fruit juices (e.g., grapefruit, orange, or apple juice) is generally avoided as this may compromise drug absorption.

---

Population and Procedural Context

Dose adjustments are utilized for specific patient populations. For individuals with impaired renal function (kidney issues), a reduced initial daily dose, such as 60 mg, is typically necessary. No specific initial dose adjustment is generally required for older adult or geriatric patients based on age alone. If a dose is missed, the recommended procedural guidance is to skip the missed dose and take the next dose at the scheduled time, without taking a double dose to compensate. The duration of use is generally categorized as either short-term for seasonal episodes or long-term for the maintenance of chronic conditions.

Research Evidence / Overview of Studies for Allegra 120 (Fexofenadine)

This overview summarizes the official research conducted on fexofenadine hydrochloride (the active ingredient in Allegra 120) by looking at the types of studies it was studied for, what was measured, and what the research still leaves uncertain. This summary relies solely on formal clinical evaluation evidence and is not intended as medical advice.

---

Evidence for Use in Seasonal Allergic Rhinitis (SAR)

The research base for fexofenadine's use in hay fever symptoms primarily includes short-term randomized controlled trials (RCTs). This type of research was evaluated in settings exploring how symptoms change over time.

Research examined outcomes related to physical discomfort and functional imbalance. The studies recorded measurements using the Total Symptom Score (TSS), which is a composite measure of how patients reported their experience with outcomes linked to inflammatory or irritative states, such as sneezing, runny nose, and itching of the eyes, nose, or throat. These trials were conducted during periods of increased symptom activity. Studies report how symptoms evolved in the observed populations during the short study period, and studies report the measurements obtained during the study period.

---

Evidence for Use in Chronic Idiopathic Urticaria (CIU)

Research exploring fexofenadine's role in Chronic Idiopathic Urticaria (CIU), or chronic hives, also primarily involves short-term, placebo-controlled RCTs. These studies was evaluated in research contexts involving fluctuating or unstable symptoms related to the skin condition.

The studies explored patient-reported outcomes describing perceived discomfort. Researchers focused on measuring the Pruritus Severity Score (how intensely patients reported their itching) and the Number of Wheals Score (how many hives were visible). These measured scores were monitored in studies conducted during periods of increased symptom activity. Findings describe patterns observed in the studies regarding the patterns observed in the recorded data for both itching and the appearance of wheals.

---

What is Still Uncertain in the Research Landscape

The evidence provides context but not individual predictions; findings describe group patterns, not personal outcomes. The primary evidence focuses on short-term periods, meaning controlled data regarding the maintenance of symptom control over extended periods is lacking.

While studies explored specific pediatric age groups, the certainty remains low for some very young populations, and comparative evidence for those with co-occurring medical conditions is lacking. The results apply only to the populations studied and does not determine whether an individual will respond similarly.

Common questions about Allegra 120 (FAQ)

---

Q: Is Allegra 120 considered a long-acting or short-acting medicine?

Allegra 120 (fexofenadine) is formulated for once-daily use, according to official product information. This means the medicine is formulated for an intended duration of effect that supports continuous coverage over a 24-hour period, consistent with long-acting treatments described in regulatory definitions.

---

Q: Does Allegra 120 contain pseudoephedrine or any decongestants?

The Allegra 120 mg tablet contains fexofenadine hydrochloride as the only active ingredient. Official labeling indicates this is a single-ingredient product. Combination products, which contain decongestants like pseudoephedrine, are available and marketed separately (often labeled as Allegra-D).

---

Q: What is the difference between Allegra 120 and other non-drowsy allergy medicines?

Fexofenadine is officially classified as a second-generation, non-sedating antihistamine. Regulatory documents explain its action is highly selective for peripheral histamine receptors, meaning it acts primarily outside of the brain. This limited ability to cross the blood-brain barrier is consistent with its low potential for causing drowsiness. Its second-generation classification signifies this targeted action.

---

Q: What is the expected duration of effect after taking Allegra 120?

Fexofenadine is designed for once-daily use to provide intended coverage over a 24-hour period. Studies show that the antihistamine effect begins within one hour of administration. The maximum effect on relieving allergy symptoms is generally observed between 2 and 6 hours after the dose is taken.

---

Q: Is there any research that discusses Allegra 120 use in older adults?

Limited clinical data is available regarding the use of fexofenadine in older adults. While a dose adjustment is not routinely required based on age alone, official pharmacokinetic studies have noted that the maximum concentration of the drug in the blood was observed to be higher in older adult subjects compared to younger subjects in the study population.

---

Q: Do official patient leaflets mention any contraindications related to heart conditions?

A known contraindication exists for patients with hypersensitivity to any component of the tablet. While not a formal contraindication, official warnings state that caution is required for patients with a history of cardiovascular disease. This caution is based on the general class of antihistamines being associated with rare reactions such as an increased heartbeat (tachycardia) or palpitations.

---

Q: Are there different strengths of Allegra available, and what does the '120' refer to?

The number '120' refers to the strength of the tablet in milligrams (mg) of the active ingredient, fexofenadine hydrochloride. The medicine is available in various strengths and formulations, including 60 mg and 180 mg tablets, and oral suspension (liquid) forms, depending on the regulatory region.

---

Q: What does the research say about Allegra 120 for seasonal versus perennial allergic rhinitis?

Fexofenadine is formally indicated for the relief of symptoms associated with Seasonal Allergic Rhinitis (SAR), commonly known as hay fever. While the drug is often used for persistent, year-round symptoms, regulatory documents and clinical trials may focus their official evidence specifically on the seasonal indication.

---

Q: Does Allegra 120 interact with common pain relievers like Ibuprofen?

Official regulatory texts do not list documented or specific interactions between fexofenadine and common non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen. The documented interactions primarily involve certain antibiotics, antacids, and fruit juices.

---

Q: Is it generally safe to take Allegra 120 with vitamins or mineral supplements?

Regulatory guidance indicates that there is not enough data to confirm the safety of complementary medicines, herbal remedies, and supplements with fexofenadine. Official documentation often reminds patients that a healthcare professional is the correct resource for questions regarding all supplements. Caution is specifically noted for supplements that cause drowsiness or have anticholinergic effects.

---

Q: Does Allegra 120 interact with any types of antidepressant medications?

Primary regulatory texts do not explicitly document specific interactions between fexofenadine and modern antidepressant medications. The main concern for drug interactions relates to the potential for additive effects with other medicines that cause drowsiness or have anticholinergic properties.

---

Q: How quickly is Allegra 120 described to start working?

Regulatory studies have shown that the drug begins to exhibit its antihistaminic effect and relieve symptoms within one hour of administration. The maximum effect is typically observed in the first few hours after taking the tablet.

---

Q: If Allegra 120 doesn't seem to work, what is generally suggested in official documents?

Regulatory documents state that patients should discontinue use and seek professional medical guidance if symptoms persist, worsen, or change unexpectedly. Procedural guidance for a missed dose recommends skipping it and taking the next dose at the scheduled time.

---

Q: Is Allegra 120 available over-the-counter or only by prescription?

Fexofenadine hydrochloride is widely available for purchase over-the-counter (OTC). This availability means a prescription is not required to obtain the medicine.

---

Q: Does Allegra 120 carry a risk of anticholinergic side effects?

Fexofenadine is a selective H₁-receptor antagonist. Official regulatory reviews note that no anticholinergic effects were observed in laboratory animal studies. Anticholinergic effects refer to side effects like dry mouth or blurred vision.

---

Q: Is it normal to feel a dry mouth after taking Allegra 120?

Official adverse reaction data includes reports of dry mouth in clinical trials with fexofenadine. Therefore, experiencing dry mouth is a recognized possibility documented in the official safety information.

---

Q: Is Allegra 120 known to cause any issues with blood pressure?

Fexofenadine is not typically associated with raising blood pressure. However, caution is advised for patients with existing cardiovascular disease due to the potential for rare reports of palpitations (a fast, noticeable heartbeat) or fast heart rate.

---

Q: What studies exist regarding Allegra 120 and its impact on performance or driving?

Regulatory bodies have concluded that fexofenadine is unlikely to affect the ability to drive or use machines. This conclusion is based on its pharmacodynamic profile and the results of objective tests, which show no significant effect on central nervous system function at therapeutic doses.

---

Q: Can Allegra 120 affect the results of allergy skin tests?

Studies indicate that as an antihistamine, fexofenadine can interfere with the results of allergy skin testing by suppressing the skin's reaction to allergens. Healthcare professionals typically advise temporarily stopping the medicine for a period before a skin test is conducted.

---

Q: Is Allegra 120 available in liquid or suspension forms?

Yes, Fexofenadine is available in other formulations besides the standard tablet. Official dosage forms listed in regulatory documents include an oral suspension, which is a liquid form of the medicine.

The storage and disposal of Allegra 120 (Fexofenadine Hydrochloride) tablets are defined by regulatory labeling to preserve the product's quality and ensure safety.

Official Storage and Disposal Statements

Storage/Disposal Domain	Regulatory Requirement
Temperature	Store at 20 C to 25 C (68 F to 77 F) with excursions up to 30 C.
Protection	Keep in the original package and protect from moisture and excessive heat.
Child Safety	Keep this medicine out of the sight and reach of children.
Disposal	Do not dispose of via wastewater or household waste; return unused or expired tablets to a pharmacist or official drug take-back program.

Official documents require the tablets to be stored at a controlled room temperature and protected from moisture to maintain stability until the expiration date. Furthermore, the product must be stored away from children, and disposal must be handled through regulated programs to prevent environmental contamination.