Misleading score-lines on tablets: facilitated intake or fractional dosing?

QUESTION UNDER STUDY / PRINCIPLES: Scored tablets are often split to facilitate swallowing or to fractionate the dose. In the latter case, the fragments of the tablet should comply with the content or mass uniformity requirements of the European Pharmacopoeia. For health professionals the splitting information is expected to be in the Summary of Product Characteristics (SPCs), the package leaflets (PLs) or Hospital Drug Formularies. We investigated the accuracy of splitting statements in these three sources of drug information.

We selected the tablets mentioned as "scored" in the Swiss Compendium Online and in the Drug Formulary of Basel University Hospital, and screened the corresponding SPCs and PLs for information on divisibility and fractional dosing. Missing information was obtained from the drug marketing licence holder.

The Swiss Compendium Online contained 698 different scored tablets whose SPCs mentioned fractional dosing for 43.8% and explicitly forbade it for 2.7%. The Hospital Drug Formulary indexed 188 items as scored tablets. The corresponding SPCs mentioned fractional dosing for 107 (59.4%) and a sentence forbidding it for 5 (2.8%). The manufacturers' answers permitted fractional dosing for 49 (27.2%) of the remaining tablets and forbade it for 19 (10.5%). Lack of dosage uniformity or presence of "historic decorative" score-lines were the reasons given.

For the majority of scored tablets the official sources of drug information contained no explicit indication on fractional dosing. Improvement of splitting information is necessary to avoid potential medication errors.