Effectiveness and safety of levocetirizine 10 mg versus a combination of levocetirizine 5 mg and montelukast 10 mg in chronic urticaria resistant to levocetirizine 5 mg: A double-blind, randomized, controlled trial.

BACKGROUND: Chronic urticaria is a vexing problem for patients and treating physicians alike. The EAACI/GA[2]LEN/EDF/WAO guidelines advocate an increased antihistamine dosage up to four times the standard, before adding leukotriene receptor antagonists. Patients are frequently intolerant of these higher dosages. We conducted this study to determine whether the addition of leukotriene receptor antagonists to the standard antihistamine dose was comparable to higher dosages of antihistamines alone, in terms of efficacy, safety and quality of life changes. We compared levocetirizine 10 mg (double dose of standard) versus a combination of levocetirizine 5 mg and montelukast 10 mg in cases of chronic urticaria not responding to single daily dose of 5 mg levocetirizine. METHODS: A single-center, double-blind, randomized, active-controlled, parallel group phase IV trial (CTRI/2014/12/005261) was conducted on 120 patients of chronic urticaria of either sex not responding to 5 mg levocetirizine. Patients were randomized into receiving either levocetirizine 10 mg or levocetirizine 5 mg + montelukast 10 mg for 4 weeks. Primary outcome measures were Urticaria Activity Score (UAS) and Urticaria Total Severity Score (TSS). Routine hematological and biochemical tests and treatment-emergent adverse events were monitored for safety. RESULTS: Fifty-two patients on levocetirizine 10 mg group and 51 patients on levocetirizine 5 mg + montelukast 10 mg group were analyzed. UAS and TSS reduced significantly in both treatment groups and reduction of score were comparable in between the groups (P = 0.628, P = 0.824, respectively). Among adverse effects, sedation was noted significantly more (P = 0.013) in levocetirizine 10 mg group. Quality of life was significantly improved in levocetirizine 5 mg + montelukast 10 mg group (P = 0.031). LIMITATIONS: The limitation of the study was that the follow-up period was 4 weeks. CONCLUSION: EAACI/GA[2]LEN/EDF/WAO guidelines need to be more flexible in allowing usage of montelukast before escalation of anti-histamine dosage.

Histamine 2 blocker potentiates the effects of histamine 1 blocker in suppressing histamine-induced wheal.

BACKGROUND: Histamine is responsible for the wheal and flare reaction in various allergic conditions. Classical antihistamines are the drugs which block the H 1 receptors and are widely used in various allergic conditions, whereas H 2 blockers are mainly used for acid peptic disease. Although H 1 receptor-mediated actions of histamine are primarily responsible for vasodilatation, vasopermeability, and itching, it has been observed that combined blocking of both H1 and H2 receptors may provide better relief. AIM: To compare the efficacy of levocetirizine (H1 blocker) versus levocetirizine and ranitidine (H2 blocker) in suppressing histamine-induced wheal. METHODS: Fifteen volunteers were given a single dose of levocetirizine 5 mg on day 1 and a single dose of levocetirizine 5 mg with ranitidine 150 mg twice a day on day 7. A pretest was performed by intradermal histamine prick test. After administration of the drugs, the prick test was repeated at 1 hour, 2, 3, 6, and 24 hours, and the size of the wheal measured and statistically analyzed. RESULTS: At 1 hour, there was no statistically significant difference in the wheal size between levocetirizine alone and the combination of levocetirizine and ranitidine. Levocetirizine with ranitidine resulted in statistically significant reduction of wheal size at 2, 3, 6, and 24 hours when compared with levocetirizine alone. CONCLUSION: H2 blocker potentiates the effects of an H1 blocker in suppressing histamine-induced wheal.