The Effects of Loratadine

Loratadine, most commonly sold in the U.S. as Claritin, is a long-acting antihistamine used to treat allergies. Most effects associated with allergies are caused by histamine release from mast cells of the immune system. Loratadine prevents the activation of other immune cells by histamine, diminishing the possibility of allergic reactions. The drug in most cases has no side effects or only minor ones; however, there are a number of known serious side effects as well.

Minor Side Effects

• Loratadine's most common minor side effects include headache, fatigue and dry mouth. Loratadine does not reach the brain and therefore almost without exception does not cause drowsiness if taken in the recommended dose. However, in a few cases, drowsiness can occur. Other minor reactions include nausea and temporary or prolonged dizziness.

Persistent Minor Effects

• Loratadine can also cause persistent adverse side effects, especially if used above the recommended dosage level. Bouts of coughing with a sporadic or continual sore throat can occur after use. Appetite may also be affected. Some users suffer loss of appetite or experience disturbances in their eating patterns or have a mildly upset stomach. Periods of acute thirst have also been reported.

  More persistent effects are nervousness and sleeplessness. Changes in mood also can occur with use as well as itching, rash and hives.

Serious Side Effects

• Rarer still are severe reactions to loratidine. Although loratadine is taken to alleviate allergic reactions, it has, ironically, been known to cause them instead. Swelling of the face, lips, mouth and tongue can occur. More seriously, there can be difficulty in breathing, tightness felt in the chest area and chest pain. An irregular or rapid heartbeat can accompany these symptoms.

  Loratadine has also been known to cause difficulty in urinating.

  The most serious side effects of this drug are uncontrolled tremors, shaking of the limbs and seizures.