The World Allergy Organization reports that as many as 40 percent of the population throughout the world suffer from allergies. Although there is no permanent cure for allergies, there are many medications available to help control sneezing, watery eyes and other symptoms. One such drug is the prescription medication fexofenadine, which is available in the United Kingdom under the brand name Telfast. Despite its effectiveness, Telfast presents risks for side effects and complications in some patients.
Common Side Effects
Approximately 11 percent of Telfast users report headaches, making this the most common side effects of the drug. Vomiting and indigestion are also common, occurring in at least 5 percent of users. Around 3 to 4 percent of patients who take Telfast experience diarrhea, back or muscle pain coughing, and increased incidences of upper respiratory tract infections.
Other Side Effects
Telfast also may cause other troublesome or annoying, but not dangerous, side effects. Gastrointestinal side effects include nausea and stomach discomfort. Approximately 1 percent of patients who take Telfast experience dizziness, drowsiness and fatigue, while infrequently patients report opposite symptoms, including nervousness and insomnia. Some patients develop pharyngitis, ear infections and a runny nose while taking Telfast. Around 2 percent of women who take Telfast experience severe menstrual cramps. Additional side effects of Telfast include fever and generalized body pains.
Do not take antacid medications within 15 minutes of Telfast; doing so decreases the effectiveness of fexofenadine. Antibiotic drugs like erythromycin and antifungal drugs like ketoconazole also cause additional side effects from Telfast. Because citrus juices have similar effects, do not take Telfast with orange or grapefruit juice.
Though rare, Telfast has the potential to cause serious allergic reactions in some patients. The first sign of an allergic reaction is often the formation of hives and itching around your mouth and lips. In some patients, reactions worsen, causing wheezing, shortness of breath and heart palpitations. Very severe hypersensitivities to Telfast may result in shock or even death. If you experience any signs of an allergic reaction at any point while using Telfast, seek prompt emergency medical care.
Because there is not yet sufficient evidence that Telfast has no unwanted effects upon the fetus, doctors typically do not prescribe the drug for pregnant women. Doctors do not prescribe the drug for nursing mothers due to potential side effects to breastfeeding infants. Side effects are more common in children under age 12. If you have a history of kidney disease, decreased kidney functioning or cardiovascular disease, your doctor is not likely to prescribe Telfast for you/ Since it has the potential to cause dizziness and drowsiness, you should not operate a motor vehicle or heavy machinery until you know how Telfast will affect you.