Claritin is the third of a new generation of allergy medicines called
histamine H1 receptor antagonists.
These nonsedating antihistamines are
changing the way doctors control allergy symptoms.
Until these drugs
became available, virtually all oral allergy medicines caused some degree of
sedation. This made driving or operating machinery dangerous.
Nonsedating antihistamines like Claritin now provide many people
management of symptoms such as sneezing or hives without reducing alertness or
coordination. And unlike other allergy medicine, Claritin does not appear to
interact with sedatives.
In one popular prescription product, Claritin-D,
loratadine is combined with the decongestant pseudoephedrine for quicker relief
Side Effects and Interactions
Side effects with Claritin are not common, but
people have reported headache, fatigue, drowsiness and dry mouth.
potential reactions include weight gain, blurred vision, weakness, dizziness,
nausea, anxiety, depression, impotence and menstrual changes. Report any
symptoms to your doctor.
For Claritin-D, the most common side effects
are headache, insomnia, and dry mouth. Indigestion and loss of appetite are
reported in addition to side effects listed for Claritin alone.
drugs can interact with Claritin to raise blood levels of the antihistamine.
Nizoral is known to boost blood levels of Claritin, but no changes in
heart rhythm or electrocardiogram (ECG) were noted as a result. In general, it
would be wise to check with your doctor or pharmacist if you must take Claritin
in combination with a medicine known to interact with the similar drugs,
Hismanal and Seldane.
These include erythromycin (E.E.S., E-Mycin, ERYC,
Ery-Tab, Erythrocin Stearate, etc.), Biaxin, Sporanox or Tagamet.
pseudoephedrine component of Claritin-D can reduce the effectiveness of many
blood pressure medicines and may interact with Lanoxin.
Check with your
pharmacist and physician to make sure Claritin or Claritin-D is safe in
combination with any other drug you take.
Antihistamines should be avoided for several days before allergy skin testing, as they could interfere with the results.
People with liver problems should get a reduced dose of Claritin, as they process it less efficiently.
Recent animal research suggests that Claritin and other antihistamines may promote tumor growth. We hope that further research will clarify this risk.
People with cancer or at high risk of cancer should discuss this animal data with their physicians.
Claritin-D is not appropriate for people with narrow-angle glaucoma or urinary retention. It should not be taken by anyone on Eldepryl, Nardil, Parnate, or any other MAO inhibitor.
Taking the Medicine
Claritin is a long-acting antihistamine. One tablet daily will provide 24 hour coverage.
Claritin should be taken on an empty stomach, as food substantially interferes with
absorption. That means at least one hour before eating or two hours after a meal.
Claritin-D is also taken on an empty stomach, but two a day, 12 hours apart, are required for maximum effectiveness.