How long to take Doxycycline?

[hansjd]

I have a question regarding the antibiotic Doxycycline. I have been taking it for 11 weeks as a malaria prophylactic while travelling in Africa, but I understand from reading on this forum and elsewhere that it can be helpful in fighting PC. Is it safe to continue taking it for the PC? If so should it be taken continuously?intermittently? If intermittently what regime would be a good one? Any thoughts would be much appreciated. All the best to all of you.

[GP24]

Where did you read that Doxycycline can fight cancer? I would not take an antibiotic for an extended period to avoid resistance against antibiotics.

Recently Chloroquine, also a malaria prophylactic, was mentioned as a possible drug to combine with Bicalutamide/Casodex to fight cancer:

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[Kentucky1]

My personal experience with doxycycline goes way back almost 30 years. I have taken it or minocycline or tetracycline for acne/rosacea off and on since I was a teenager. The longest stretch was for about 12 years on a daily basis. As antibiotics go, it was tolerated well with few , if any side effects. Currently it's medical use is pretty much restricted to dermatologic use. It is used for malaria prophylaxis in patients unable or unwilling to take Larium or Proguanil,or for travel to areas where the more commonly used anti-malarials have seen resistance, like Thailand.

As with any antibiotic there may be side effects, the most common being GI issues ( more common with the tablet form than the capsule), photosensitivity reactions and skin rashes.

Overall it's regarded as a fairly safe and well tolerated medication.

It's use in cancer therapy probably comes from it's effect on mitochondria and it's thought to disrupt glutamine oxidative phosphorylation,MMP-9 suppression,and alteration of fatty acid oxidation, all in line with Jane McLelland's theory of "starving" cancer cells. It is one of the COC protocol medications and is taken once daily for a month and then alternating monthly with mebendazole.

As with any medication make sure you check for drug interactions with your current meds and have your prescribing physician monitor you for any side effects.

[hansjd in reply to Kentucky1]

Thanks very much for your reply. The anti-cancer effects of Doxycycline that I'd read about were as you describe. Not clinical trials, but indications that it negatively affects CSCs. Unfortunately it also seems that CSCs resistant to Doxycycline will develop, which is why I wondered if perhaps intermittent use, as you suggest, would be the way to proceed. Something to contemplate. The variables seem endless.

[hansjd in reply to Kentucky1]

I have some more questions I would appreciate you answering if you don't mind:

1) With the COC protocol you mention, in which doxycycline is taken for a month alternating monthly with mebendazole, what dose of doxycycline is recommended?

2) Is the mebendazole taken daily or on a 3-days-on, 4-days-off regime that I've read about for taking fenbendazole (the pet alternative)?

3) What dose mebendazole is recommended?

4) Do you know if fenbendazole is as good? better? not as good?

Thanks for any information you can give me. Cheers

[Kentucky1 in reply to hansjd]

The standard dose of doxycycline is 100mg daily. The mebendazole dose is 100mg daily. So doxy daily for 30 days,then mebendazole for 30 days. Can't answer the fenbendazole question,but it appears they are closely related chemically. It is a veterinary med. I know that my mebendazole comes from a compounding pharmacy and is not easy to find. I think people are using fenbendazole because it's what they can get.

[hansjd in reply to Kentucky1]

Once again, thanks very much. I appreciate your input.

[tallguy2]

I am headed to South Africa next April and very much need to understand what everyone is saying on this forum. To take an anti-malarial or not while on ADT and having MCRPCa?

[hansjd in reply to tallguy2]

Doxycycline is the malaria prophylactic that was prescribed for me here in Australia. It seems to be the one that is commonly used for travel in Africa. I'm on ADT as well and am HSPC but I don't believe there is any problem taking both ADT and Doxycycline even if you are MCRPC. In fact it would appear that Doxycycline is beneficial in fighting PC (see discussion above). Enjoy South Africa!