Fexofenadine is an antihistamine that works against the naturally occurring chemical histamine in your body. Histamine is the chemical mediator for an allergic response. Antihistamine is also termed as antipruritic, “pruritus” means itchiness. It is a long-acting antihistamine.
Fexofenadine is used to prevent sneezing, runny nose, itching and watering of the eyes, and other allergic symptoms like chronic idiopathic urticaria, seasonal and perennial allergic rhinitis and allergic conjunctivitis.
Special precautions: Renal and hepatic or liver impairment, pregnancy, lactation and elderly age group. It is not known though that this medicine passes into the breast milk or whether it will harm an unborn baby (US FDA pregnancy category C). So, inform your doctor if you are pregnant or nursing a baby. You may also require dosage adjustment or special monitoring during treatment with fexofenadine if you have other illnesses. Fexofenadine is not approved for use by children younger than 6 years of age. Symptoms of fexofenadine overdose is not well known, nevertheless, seek medical attention if ever you notice any unusual symptom while taking this medicine.
Take fexofenadine exactly as directed. Take each dose with a full glass of water. It is usually taken twice a day, one in the morning and one in the evening. Never take more of this medication than is directed by your doctor. If your condition is not improving while taking this drug then inform your doctor so further steps for proper management may be done. Store fexofenadine at room temperature away from moisture and heat.
Serious side effects: Rarely, you experience an allergic reaction (difficulty breathing(dyspnea) ; closing of the throat; swelling of the lips, tongue, or face; or wheals/hives). Seek emergency consult if you have any of the above reactions and stop taking fexofenadine immediately. Other less serious side effects are: nausea, headache, drowsiness, dizziness, fatigue and gastrointestinal upset. You may continue fexofenadine in this case but talk to your doctor.
Drug interactions: There is a 2x-3x increase in plasma level when co-administered with erythromycin and ketoconazole. Do not take fexofenadine close to a dose of an antacid that contains aluminum or magnesium such as Rolaids, Maalox, Mylanta, Milk of Magnesia, Pepcid Complete, and others. These antacids may decrease the effects of fexofenadine.
Drugs other than those listed here may also interact with fexofenadine. Talk to your doctor and pharmacist before taking other medications, including herbal products.
Fexofenadine hydrochloride is a white to off-white crystalline powder. It is freely soluble in methanol and ethanol, slightly soluble in chloroform and water, and insoluble in hexane. Fexofenadine hydrochloride is a racemate and exists as a zwitterion in aqueous media at physiological pH. ALLEGRA is formulated as a tablet for oral administration. Each tablet contains 30, 60, or 180 mg fexofenadine hydrochloride (depending on the dosage strength) and the following excipients: croscarmellose sodium, magnesium stearate, microcrystalline cellulose, and pregelatinized starch. The aqueous tablet film coating is made from hypromellose, iron oxide blends, polyethylene glycol, povidone, silicone dioxide, and titanium dioxide.
Fexofenadine has the following structural formula: