Organon §41

Complicated diseases occur in nature, however they result much more frequently from protracted allopathic treatment. The natural disease and the artificial medicinal disease pair up and render the patient doubly diseased. 

Incomparably more frequent than natural dissimilar diseases associating and complicating themselves in the same body are those disease complications that the inexpedient medical procedure (the allopathic mode of treatment) tends to bring to pass through the protracted use of unsuitable medicines. As a result of the persistent repetition of unfitting medicines, new, often very protracted disease states (corresponding to the nature of the allopathic medicines) associate themselves to the natural disease to be cured. These new disease states gradually pair up and complicate themselves with the dissimilar chronic malady that the unsuitable medicines could not cure through similar (i.e. , homeopathic) action. In this way, a new, dissimilar, artificial chronic disease is added to the old natural disease, thus making the hitherto simply diseased individual doubly diseased, that is, much more diseased and more incurable, sometimes even entirely incurable. This double disease often kills. Several disease cases presented for consultation in medical journals, as well as other cases in the medical literature, document this.

Cases of already complicated natural diseases, which are  further complicated by allopathic treatment, are incurable or extremely difficult to cure.

Of the same kind are the frequent cases where syphilis is complicated with the itch diathesis, as well as the less frequent cases where syphilis is complicated with the wasting sickness of the figwart gonorrhea. These already complicated diseases are not cured under protracted, frequently repeated treatments with large doses of unfitting mercurial preparations. Rather, the already complicated disease takes its place in the organism beside the chronic mercurial wasting sickness 97 which has gradually been engendered. These form an often ferocious monster of complicated disease (under the general name of masked venereal disease) which is either entirely incurable or is only restored with the greatest difficulty. 

Comment
97 This occurs because mercury has in its mode of action, besides the symptoms which are similar to those of venereal disease (by which it can cure venereal disease homeopathically) still many other symptoms which are dissimilar to syphilis, such as bone-swelling, caries, etc. Therefore, the application of large doses of mercury, especially in the so-frequent complications of syphilis with psora, gives rise to new maladies and disturbances in the body.