ADVERSE DRUG EVENTS RELATED TO DOSAGE FORMS AND DELIVERY SYSTEMS

While some of the adverse events caused by the administration of medic ines are specifically attributable to the drug molecule, a proportion arises because of the chemical, biological and physical nature of the formulation. The effects may be compounded by certain patient factors, an incomplete understanding of the behaviour of the formulation or th e coadministration pf other drugs, This review examines adverse drug r eactions and other adverse events arising from the nature of the dosag e form or formulation used. These adverse effects may be the result of local irritation/toxicity, hypersensitivity or allergic reactions, sy stemic effects from essentially local therapies, or idiosyncratic reac tions in a small number of individuals. In certain cases where the exa ct nature of the formulation is unknown, adverse events cannot be attr ibuted to any single ingredient. In addition, the total of all ingredi ents of a formulation, even where details of the formulation are clear , may give rise to abnormal behaviour of the formulation in vivo. Ofte n the desired objective of a particular specialised formulation leads to an unforseen but related adverse effect, and in certain instances t hese events are completely unpredictable and at variance with the perc eived objectives of the formulation.