Clinical evidence,mechanism, importance and management
Healthy subjects were given terfenadine 60mg every 12 hrs for 14 days,with montelukast 10mg daily from day 8 to day 14. It was found that terfenadine pharmacokinetics and QTc interval were unaltered by concurrent use (See reference number 1). No adverse interactions were seen in large numbers of patients given montelukast 10 or 20mg and loratadine 10 mg, and combination was found to be beneficial in treatment of allergic rhinitis and conjunctivitis (See reference number 2). No special precautions are therefore needed if these drugs are given concurrently.
Holland S,Gertz B, DeSmet M, Michiels N, Larson P, Freeman A, Keymeulen B. Montelukast(MON) has no effect on terfenadine (T) pharmacokinetics (PK) or QTc. Clin Pharmacol Ther (1998) 63, 232.
Malstrom K,Meltzer E, Prenner B, Lu S, Weinstein S, Wolfe J, Wei LX, Reiss TF. Effects of montelukast (a leukotriene receptor antagonist), loratadine, montelukast + loratadine and placebo in seasonal allergic rhinitis and conjunctivitis. J Allergy Clin Immunol (1998) 101, S97.