Stuffy nose, runny nose, sneezing, coughing and headache are all miserable symptoms of respiratory allergies. These symptoms can cause us to miss school, work or quality time with our family or friends. Luckily, over the counter (OTC) allergy medications, such as antihistamines and decongestants, can prevent or alleviate some of these symptoms. If OTC medications do not work well, your doctor may prescribe an inhaled corticosteroid to help your symptoms. Although allergy medications can provide relief, you should be aware of the possible side effects of common allergy medications.
Antihistamines
Antihistamines work by blocking receptors that are activated by histamine, a chemical signal. Histamine is responsible for sneezing, coughing, rash, flushing and headaches that occur with exposure to an allergen. There are two categories of antihistamines that are commonly used. The first-generation antihistamines are older antihistamines, such as diphenhydramine (Benadryl). These antihistamines have broader effects on the body because they block histamine receptors in the brain. Therefore, they cause the most side effects, focused on the central nervous system. The side effects include sedation, fatigue, dizziness and headache. Second-generation antihistamines, such as loratadine or cetirizine, have more local effects on the respiratory tract. They do not have strong effects on the central nervous system, according to the American Academy of Family Physicians.
Decongestants
Decongestants, such as phenylephrine, relieve respiratory allergies by causing blood vessels in your nasal sinuses to shrink. This reduces the pressure in your nasal sinuses, and allows you to breathe better. The reduction in pressure can also help relieve a sinus headache. According to Drugs.com, side effects of decongestants include dizziness, restlessness, lightheadedness, tremors and numbness. Limit your use of nasal decongestants to less than one week; otherwise, abrupt discontinuation can result in severe congestion.
Inhaled Corticosteroids
Corticosteroids treat respiratory allergies by reducing inflammation in the respiratory tract so the airways will be wider and allow better air passage. According to Drugs.com, inhaled corticosteroids, such as fluticasone, can cause weakness, fatigue, nausea, vomiting, vision problems, breathing problems and rash. If you are experiencing any of these side effects, consult your doctor immediately so your medications can be adjusted.
