When a marketing authorisation for a drug is granted, it includes a summary of product characteristics (SPC). The summary contains information approved by the relevant drug regulatory body, and agreed upon with the company. The Vidal, the French datasheet compendium, provides information on a vast number of drugs, based primarily upon these SPCs.
The regional pharmacovigilance centres in Limoges and Marseille have pointed out inconsistencies in the SPCs published in the Vidal.
Some drugs require dosage to be adjusted for patients suffering from kidney failure. But, depending upon the drug, the dosage adjustments specified in the SPCs use different laboratory markers, a source of confusion that can lead either to an overdose, or to treatment being ineffective.
Furthermore, 228 drugs are listed in the Vidal as having no adverse effects, according to their SPCs. However, the French pharmacovigilance database contains reports of adverse effects for each one of these drugs.
Health professionals would do better not to rely upon the Vidal, but instead to use independent, comparative sources such as the Belgian Répertoire commenté des médicaments, or Great Britain's BNF.
©Prescrire December 2007
Source:
"RCP des médicaments : trop d'incohérences et de lacunes" Rev Prescrire 2007 ; 27 (290) : 935.
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