Claritin (loratadine) Info???
Quote:
>> >Any info on the drug above would be appreciated. Not in 1993 PDR.
>> >Precautions, Side-effects, dosage, administration.
>> It's a non-sedating antihistamine. 10mg once a day. Relatively
>> rapid-acting compared to Hismanal. Terfenadine (Seldane)
>> and astemizole (Hismanal) have been associated with cardiac
>> arrythmias in overdose or when mixed with certain {*filter*} like
>> erythromycin which decrease their metabolism and elevate their
>> {*filter*} levels. As far as I know, this has not yet been found with
>> loratadine.
>Steve, You may want to re-read your pharmacology book on this. Most
>anti-histamines (if not all) cause cardiac arrythmias in overdose. It is then
>reasonable to expect loratadine to cause the same.
Pharmacology supports Nigel concerns. Loratidine is similar to Terfenadine
and astemizole in: 1- its specificity for H1 receptors, 2- the existence
of active metabolites (potential for interaction with enzymatic pathways),
and 3- absence of direct muscarinic effect of the substance.
As H1 receptors are responsible of inotropic effects, it is sounded that
overdose can affect cardiac functions.
As far as the approval process is concerned: it is in the late months of
1982 that the company filled claims with the FDA and several other regulatory
agencies. NDA was filled in October 1986 (USA), Recommended for approval
by FDA's Pulmonary-Allergy Ad. Cttee (Oct. 87). FDA raised concerns
with formulation (capsule vs tab) in 1989 and human carcinogenicity potential
of antihistamines (June 1991). FDA approval was granted on April 12, 1993.
Ecole de Pharmacie, Universite Laval, Quebec
