Since 1985 Isoprinosine, also known as Imunovir is known as an adjuvant treatment for AIDS, cancer and age-associated immune impairment. There have been more than 60 articles published on Isoprinosine and cancer since 1972. Isoprinosine, its characteristics and its usefulness in relevant indications are discussed here. Isoprinosine is an immunomodulator and is currently (as of December 2001) approved for immunorestoration in chemotherapy in some countries. Patients on chemotherapy are particularly susceptible to different viral infections as a result of chemotherapy-induced immunodepression. Adjuvant therapy with Isoprinosine can restore the cell-mediated immune response to the individual’s baseline levels.

It can therefore be prescribed during chemotherapy to restore the immune response and as a prophylaxis against reactivation of latent herpes simplex or herpes varicelliform zoster (shingles) infections, or for treatment or management of other secondary viral infections.

In these instances, the dosage used is the standard 50 mg/kg/day of lean body weight, up to a maximum of 3g daily (6x 500 mg tablets), divided evenly during waking hours. Schedule of treatment depends on the type of chemotherapeutic agent used. Isoprinosine is only administered after the infusion and only when the desired immune suppression against the cancerous cells has taken effect. At that point between infusions when it is desirable for the immune system to normalise, Isoprinosine treatment is initiated in order to enhance the normal immune response recovery. The number of treatment days depends on the length of time between infusions and also the immune profile of the individual patient.

Isoprinosine can also be administered for immunorestoration after chemotherapy, surgery or radiation.

It is important to note that Isoprinosine is not approved for the treatment of the neoplasia per se. There is no data on the effect of Isoprinosine on cancer itself or the effect on the progression of the disease.

1. How Does Isoprinosine Work? Isoprinosine is a synthetic purine derivative with immunomodulatory and antiviral properties, which result from an apparent in vivo enhancement of host immune responses due to the drug.

The action of Isoprinosine can be summarized as follows:

Normalizes the cell-mediated immunity by stimulating the differentiation of T-lymphocytes into T-cytotoxic cells and T-helper cells and increasing lymphokine production Increases production of IL-1 (interleukin-1) and IL-2 (interleukin-2) and IFN-? (gamma interferon) Increases NK cell (natural killer cell) function Increases the humoral immune response by stimulating the differentiation of B- lymphocytes into plasma cells and by enhancing antibody production Increases the number of IgG and complement surface markers Potentiates neutrophil, monocyte and macrophage chemotaxis and phagocytosis Inhibits viral growth by suppressing viral RNA synthesis while potentiating depressed lympocytic RNA synthesis and translational ability

2. Other Benefits of Isoprinosine Treatment: Studies have documented the ability of Isoprinosine to slow the progression of AIDS in HIV-infected persons by increasing the total number and activity of T-cells, T-helper cells and NK (natural killer) cells. The largest study, which was published in The New England Journal of Medicine on June 21, 1990 found that HIV infected people with CD4 cells count over 500 experienced significant benefits from Isoprinosine therapy. T-lymphocyte defects are common in cancer and AIDS patients according to a study in Medical Oncological Tumor Pharmacotherapy in 1989, which found that Isoprinosine and levamisole (another immune-boosting drug) mimic the actions of the thymic hormones to promote T-cell development. Combinations of Isoprinosine, low-dose Interleukin 1 and 2, and other immune-modulating hormones such as Melatonin are suggested as possibly effective cancer therapies.

3. Prescribing Information: The prescribing physician will ultimately decide about the details of therapy (dosing, duration, etc.). According to dosing information obtained from published references; patients with cancer can take 2000 mg to 3000 mg of Isoprinosine daily for two months(2-3g/day; 4-6 tabs of 500 mg inosine pranobex). Then they may stop taking Isoprinosine for two months, and then resume taking it at the same dose for another two months.

Caution! Before starting to take this medicine, it is vital that you should consult your doctor! Do not use it on your own initiative, without medical advice.