Levamisole

Levamisole (Ergamisol, HCl salt) is an antibiotic belonging to a class of synthetic imidazothiazole derivatives. It was discovered at Janssen Pharmaceutica in 1966.

Clinical use
It was originally used as an antihelminthic to treat worm infestations in both humans and animals.

It has been tested in combination with fluorouracil to treat colon cancer. There is no good evidence from clinical trials that its addition to fluorouracil therapy benefits patients with colon cancer, and it is no longer used for this. It is also used infrequently to treat melanoma and head and neck cancer. It is unclear from its mechanism of action why it would have an effect in treating colon cancer, although it has been shown to have "immune-stimulating" properties in some situations.

A 1984 study on complicated viral influenza had found levamisole to be an effective interferon inducer and had recommended its use in combination therapy for influenza.

It is also used routinely in India to treat steroid dependent childhood nephrotic syndrome cases, and is probably based on literature published in a few UK based studies.

Laboratory use
Levamisole reversibly but uncompetitively inhibits (independent from presence or absence of Mg2+) most alkaline phosphatase isoforms (eg human liver, bone, kidney, and spleen) except the intestinal and placental isoform.

It is thus used as an inhibitor along with substrate to reduce background alkaline phosphatase activity in biomedical research involving detection signal amplification by intestinal alkaline phosphatase for example in in situ hybridization or western blot protocols.

Administration and metabolism
Levamisole is given orally, and is metabolized primarily by the liver.