Of fifteen patients with pseudolupus (a syndrome characterised by recurrent fever, myalgia, arthralgia, pleuritis, pulmonary infiltrates, pericarditis, myocarditis, and by mitochondrial antibodies in the absence of nuclear antibodies), all had been treated with "Venocuran", one of a great number of drugs used for venous diseases. This drug, available in twenty countries under various names, contains phenopyrazone, horse-chestnut extract, and cardiac glycosides extracted from various plants. Further studies revealed that up to 90% of long-term users of venocuran acquired mitochondrial antibodies. This was not true for patients with venous diseases being treated with other drugs. About 30% of long-term users of venocuran might experience prodronal symptoms, such as myalgia and arthralgia, while more than 10% could develop the full disease.