One problem with antihistamines or anti-allergy medications is their sedating or drowsy side effect. First Generation Antihistamines (FGA) like chlorphenamine, diphenhydramine and hydroxyzine have these untoward reactions. Fortunately, with Second Generation Antihistamines (SGA) like loratadine and cetirizine, the sleepy effect has been minimized. Further more, this inconvenience has been lessened by the Third Generation Antihistamines (TGA).
Zyxal (GlaxoSmithKline) is a brand of levocetirizine. Compared to the First Generation Antihistamines it has been cited for minimal drowsy side effect. However compared to TGA and SGA, it is more expensive. Cetirizine seems to be a closer alternative to levocetirizine. Not only that cetirizine is less sedating, it is often taken once a day like levocetirizine. So, does this mean that it’s OK to take cetirizine instead of levocetirizine?
Levocetirizine and cetirizine comparison
Levocetirizine and cetirizine are generally prescription medications, categorized as piperazine derivatives. Both are employed as systemic antihistamines for allergic rhinitis (sneezing, watery eyes, runny nose) and chronic urticaria (skin allergy). As a Third Generation Antihistamine, levocetirizine is actually an enantiomer of cetirizine, a Second Generation Antihistamine.
Both levocetirizine and cetirizine has less CNS penetration unlike the FGA. With this, both drugs have minimal sedating effect.
Levocetirizine can be available in 5mg tablet and in 5mg/5ml drops. It is given once a day. A 5mg tablet can be taken by an adult and children from 6 years old and above. Children from 1 to 6 years old are given half the dose (2.5mg) while infants from 6 months to 1 year old are given 1.25mg once a day.
Cetirizine on the other hand, is available in 10mg tablet, 5mg/ 5ml syrup and 2.5mg/ml drops. A 10mg cetirizine can be taken by adults and children from six years old. It is usually taken once a day. However, its dose can be divided into two - usually given in the morning then in the evening. Children from 2 to 6 years old are given half the dose of a 10mg cetirizine and infants from 6 months to 1 year old are given 2.5mg.
Precautions and contraindications
Cetirizine and levocetirizine are to be used in precaution with elderly people, pregnant women, patients with epilepsy or severe cardiovascular disorder and those who have kidney and liver problems. It is contraindicated in individuals with severe renal impairment and for those having hypersensitivity with piperazine derivatives. Levocetirizine and cetirizine is not advised for children below 6 months old.
Cetirizine has been cited for stomach pain, diarrhea or constipation, vomiting and bronchospasm side effects. However, both levocetirizine and cetirizine can also cause tiredness, sore throat and headache. More to this, both drugs can cause dizziness in susceptible individuals.
Levocetirizine or cetirizine should not be taken with alcohol, other antihistamines and antidepressant drugs.
Image by the author
Cetirizine for levocetirizine substitution
Third generation drugs are developed for greater efficiency but with the least untoward side effects. With cetirizine - an SGA, it was derived from hydroxyzine, an FGA for a less sedating side effect. A few years later, levocetirizine was created from cetirizine.
While levocetirizine is cited as better than cetirizine, there are some people who buy cetirizine as an alternative for levocetirizine. Cetirizine is cheaper and as claimed, works the same way as levocetirizine. This can be true since levocetirizine and cetirizine are chemically related. However, different individuals may not react the same way. Some may find relief in substituting cetirizine for levocetirizine, others may not. Patients can be experimental in trying other options. In the case of cetirizine and levocetirizine, these drugs are almost the same. However, an advice from a doctor is foremost recommended.
©Phoenix Montoya @ July 14, 2012