Recently, I received two separate questions about both low dose ketoconazole (LDK) and high dose ketoconacole (HDK). For both of these men with castrate resistant advanced prostate cancer, their PSA scores continued to rise, despite their using keto.

Even when taken properly, not all men experience a positive effect from the drug (a decline in their PSA). Those individuals who do experience a positive effect will usually not have this effect for long periods of time, however the time that the keto does control the PSA is well worth the effort to take the drug (ketoconazole has not been approved by the FDA for use by men with castrate resistant prostate cancer, so its use is “off label”).

When I asked them how they were taking the drug neither of them indicated that they had received any special instructions from their doctors! They made no efforts to have an acidic stomach and they both were causal about their dosing schedules. Both of these men were doomed to fail ketoconazole therapy.

There are usually two common mistakes made when taking keto:

1- They had not paid proper attention to insuring that they had adequate absorption of the drug. To have proper absorption you must have an acidic environment in your stomach, ideally a ph under 4.0. Chin et al used coca-cola classic along with the keto to increase the acidity of the stomach in his subjects (Note: The pH of blood is about 7.0 while the pH of Coca-Cola Classic is 2.5, Pepsi 2.5, Diet Coca-Cola 3.2 and Diet Pepsi 3.2, Diet Minute Maid Orange Juice 3.0. You can also try increasing the gastric acidity by taking chewable vitamin C (1000mg or more) to increase your stomach’s acidity.)

You should also avoid acid blocking drugs such as Axid, Zantac or Prilosec as they will also buffer your stomach so that it will not be adequately acidic for proper absorption.

A serum concentration of ketoconazole of 4ug/mL is required to achieve a castrate level of testosterone so if you are a no-responder
a blood test might be in order to see if you are adequately absorbing the keto.

2- Another common problem is that Keto is very quickly cleared from the body, so your scheduled dosages must be STRICTLY adhered to otherwise you will lose any advantages. Usual doses are every 8 hours, but this time period must be strictly adhered to at all times.

Joel T Nowak, M.A., M.S.W.