Highlights of the 22nd French pharmacovigilance meeting.

(1) The 22nd French pharmacovigilance meeting, held in July 2001, presented data on adverse effects notified by health professionals to regional pharmacovigilance centres in France. (2) Non specific "immunostimulants" are not harmless placebos, as might be concluded from the relative lack of data. There have been 315 notifications of severe adverse effects, some with positive rechallenge, reporting cutaneous, gastrointestinal, respiratory, haematological and other disorders. Attributability was considered "likely" in 68% of cases. Three deaths occurred. (3) Other well known adverse effects continue to occur: convulsions with camphor, visual hallucinations with oxybutynin, headache with antimigraine drugs, liver damage with dextropropoxyphene, neuropsychological disorders after buflomedil overdose (especially in patients with renal failure), hyperkalaemia during spironolactone combination with an angiotensin-converting-enzyme inhibitor (ACE inhibitor), and severe infections after intravesical BCG. (4) Rare adverse effects of old drugs were identified, such as oedema with valproic acid, interstitial pneumonia with flecainide, and a bleeding risk due to tramadol interaction with oral anticoagulants. (5) The adverse effects of new drugs are better documented: celecoxib is now implicated in visual disorders. (6) Overall, the meeting confirmed that only a small proportion of adverse drug reactions are notified, that a large number of hospitalised patients suffer from drug induced complications, and that summaries of product characteristics (SPC) are often too brief or reassuring regarding pharmacovigilance data. The poor risk-benefit ratios of some drugs call for their immediate market withdrawal.