You may report side effects to FDA at 1-800-FDA-1088.Stop using fexofenadine and call your doctor at once if you have:This is not a complete list of side effects and others may occur. Discover Your Allergy Triggers Less serious Allegra side effects may include: Loratadine may lead to agitation, confusion, anxiety and amnesia, according to RxList.com. Copyright © 2018 by RxList Inc. RxList does not provide medical advice, diagnosis or treatment. Our Allegra Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. Allegra-D (fexofenadine hcl and pseudoephedrine hcl) is a combination of an antihistamine and a Our Allegra-D (fexofenadine hcl and pseudoephedrine hcl) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. This is not a complete list of side effects and others may occur. Nervousness, excitability, restlessness, dizziness, weakness, or insomnia may occur. Is Allegra helpful for Irritability? The recommended dose of Allegra-D 12 Hour Extended-Release Tablets is one tablet twice daily taken on an empty stomach with water, for adults and children 12 years of age and older. Discover Your Allergy TriggersCould I Be Allergic? Note that the Allegra ODT tablets (orally disintegrating tablets) contain 5.3 mg of Our Allegra Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. You may report side effects to FDA at 1-800-FDA-1088.© Allegra Patient Information is supplied by Cerner Multum, Inc. and Allegra Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.Copyright © 2020 by RxList Inc. RxList does not provide medical advice, diagnosis or treatment. Call your doctor for medical advice about side effects. Call your doctor for medical advice about side effects. Psychological Side Effects. All adverse events that were reported by greater than 1% of subjects who received the recommended daily dose of the fexofenadine hydrochloride/pseudoephedrine hydrochloride combination are listed in the following table.Many of the adverse events occurring in the fexofenadine hydrochloride/pseudoephedrine hydrochloride combination group were adverse events also reported predominately in the pseudoephedrine hydrochloride group, such as insomnia, headache, nausea, dry mouth, dizziness, agitation, nervousness, anxiety, and palpitation.In placebo-controlled clinical trials, which included 2461 subjects receiving fexofenadine hydrochloride at doses of 20 mg to 240 mg twice daily, adverse events were similar in fexofenadine hydrochloride and placebo-treated subjects. Common Questions and Answers about Allegra side effects depression allegra (Hep C, Gen 1, VL 10 million 700 thousand, started treatment with 4 week lead-in of Interferon and Ribavirin on 9-1-2011) Here I am in day 14 of tx, and today I decided I should/would track my side effects better, so I … can Allegra cause Irritability? Stop taking Allegra and call your doctor if you have fever, chills, body aches, cough, or other flu symptoms. These side effects may go away during treatment as your body adjusts to the medicine. Find patient medical information for Allegra Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. It is unknown if Allegra passes into breast milk or if it could harm a nursing baby. Call your doctor for medical advice about side effects. Get emergency medical help if you have any of these signs of an allergic reaction to Allegra: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. This is not a complete list of side effects and others may occur. You may report side effects to FDA at 1-800-FDA-1088.Stop using fexofenadine and pseudoephedrine and call your doctor at once if you have:This is not a complete list of side effects and others may occur.