Azithromycin on hand if taking rapamycin?

I received my 120 tablets of Zydus and with a bit of apprehension I took a single 1mg tablet. That was yesterday. Today, I look, in the mirror, 20 years younger, uh…more or less.

I intend to go to 2mg then 3 then 4…up to 6 over 6 weeks.

I did watch this neat video:

(Dr. Alan Green)

Alan Green on Rapamycin Longevity Series | Lessons learned from over 1200 patients

In it, he talked about canker sores but also commented that about 5% (from a study) of those taking rapamycin experienced some sort of infection, since rapa affects the innate immune system.

He said to simply take some Azithromycin at the first hint of any infection. Now, I see another post which is very negative on Azithromycin so YMMV.

Question: Are any of you using Rapa keeping Azithromycin on hand, and can that be purchased along with my Rapa from RL Pharma on my next order?

Thoughts would be appreciated.


That is related to a specific context. The risk reward changes if you have an infection, and obviously if a doctor have prescribed you a treatment.

But Azithromycin seems bad in certain contexts?

There was a MD on this forum last year/year and half ago who explained why this was not a good choice and did not agree with Dr.Geen.

Azithromycin is not a good choice for counter acting a possible Rapamycin induced infection according to member “tongMD”

Search and you could located the thread.


Which antibiotic is good to have at hand then?


I think the best answer to that question is that you should consult with your physician whenever you think you may have an infection, regardless of whether you are on rapamycin or not. It’s not uncommon for patients to visit doctors believing they have a bacterial infection only to find out it’s fungal, viral, or even not an infection at all. As one example, people often make an appointment for an infected toe when it’s really just an ingrown toenail with inflammation and swelling without substantial infection. Or they mistake allergies for a sinus infection, etc.

With that said, I do stock antibiotics myself. But my background and education make me feel more comfortable making some of these decisions on my own. We did discuss this topic here in the past. There is no single antibiotic that’s a cure all for any bacterial infection. My own opinion is that when balancing spectrum of action with safety, cost, and oral bioavailability that doxycycline would be a top choice. So if I was to travel to a remote region where I didn’t have quick access to medical care, that would be a top medication to bring with a medical kit.

If someone has a doctor who prescribes them rapamycin for anti-aging, probably a more appropriate product to keep on hand may be a dexamethasone mouth rinse. Because inflammation and aphthous ulcers in the mouth are one of the most common side effects and that has been shown to help with that somewhat.


I’ll second that question… :smiley:

A couple years ago when I was taking larger and larger doses or Rapa I ended up getting penicillin from my dentist and used it on something else too. It worked great. I don’t know why she gave me a couple refills with it but I ended up using them and was glad I didn’t need another appointment.

Yikes! Regularly taking or keeping antibiotics on hand just in case would be a whole other level of faith in Rapa than I have. I’d back off the dose or frequency if I was having that sort of problem periodically.

Is there a rationale for how rapa could be worth getting infections and nuking the gut every once in a while to deal with the infections? Or is it a transient thing where the immune system will improve over time to eliminate infections?


Just make sure that you physician knows that you’re on Rapamycin, and where in the “cycle” you are on it. Meaning day 1 vs day 7.

I980 I was on Simvastatin. I developed community pneumonia and went to a walk-in clinic. The doc there put me on Erythromycin. About 4pm the next day I felt like I could hardly walk and then had a flash of insight and used a urine dipstick and the section for blood in the urine turned black, poof.

There was no “blood,” in the urine but I had developed rhabdomyolysis and there was plenty of myoglobin from damaged muscle cells. Had I kept taking that erythromycin another day I would have likely destroyed my kidneys. That doc made no attempt to look at Cytochrome P450 interactions and strangely neither did the CVS computer system that should have beeped a warning.

Due to its inhibition of CYP3A4 and ABCB1, erythromycin has been shown to result in a sixfold increase in the AUC of simvastatin, which is metabolized by CYP3A4.

What happened is the blood level of simvastatin rose to a toxic level.

W/ Rapamycin a CYP3A4 inducer would be ok (I think, correct me if I’m wrong) as that would simply cause the blood level of Rapamycin to drop, but an inhibitor such as erythromycin could cause the blood level of Rapamycin to rapidly increase, possibly by a 6x factor.

So which ones should be ok w/ Rapa?

In contrast to erythromycin and clarithromycin, azithromycin does not seem to interact with SLCO1B1 or SLCO1B3 [6]. Azithromycin has been shown to be a weak substrate for CYP3A4, to be minimally metabolized by the enzyme, and to neither induce nor inhibit CYP3A4 activity [[16]


Therefore it appears to me that Azithro would be ok, this stuff gives me a headache, but it’s important to know, especially w/ the long half-life of Rapa.


Well, a few weeks ago I had COVID and bacterial infections for a total of 3 weeks. It started with a bacterial infection and then the third week I had COVID. I took 2 courses of Azithromycin for the first two weeks one 3-day course and one 5-day course (prescribed by my doctor after he diagnosed my condition). Symptoms were gone at the end of each course but came back a couple of days later due to re-infection. I took PAXLOVID for 5 days at the end to treat the COVID (after going to the hospital and being treated by a doctor who prescribed PAXLOVID).

It was unpleasant but not life-threatening. I had a hacking cough and phlegm. The worst point was the start of COVID which made me incredibly fatigued. I had chills, a fever, and a hacking cough. I also developed the worst case of conjunctivitis I had ever had which lasted about a week. The fever and chills lasted one day as I then tested positive for COVID, went to the hospital, and started PAXLOVID. Everything got better after that.

I was taking a high dose of Rapamycin right before the infections (I took my last Rapa dose on Saturday and got sick on Thursday). I took 14 mg equivalent (4 mg + GFJ) and 10 mg equivalent (3 mg + GFJ) the two weeks before the infections. It was also peak flu season here in Hong Kong and everywhere was like a symphony of coughs so exposure to flu A, COVID, and bacteria was at its height.

I survived, but it was unpleasant. Fortunately, the docs also gave me a lot of meds in addition to antibiotics to treat the symptoms - cough suppressants, mucolytics, NSAIDs, and anti-allergy meds.

I keep a 10 day course of Azithromycin in the fridge just in case I need it. But I usually prefer to see a doctor whenever I am sick.


A lot of misinformation here. If you get sick, see a doctor. Don’t manage it on your own with random antibiotics.


Sorry. I should have mentioned that all the antibiotics and PAXLOVID were prescribed by my doctors after visiting them and getting diagnosed. They stated that I had bacterial infections. The hospital just needed to see my positive COVID test and it was easy to diagnose that.

I did not self-diagnose.


@DeStrider I was referring more to this whole topic and not your post.


DOXY maybe ???

1 Like

I do it all the time. So far I have not dropped dead yet. :joy:

1 Like

Agreed. Doxy seems to have less side effects and helps with a broad spectrum of infectious bacteria.


“CYP3A4 inhibition was demonstrated in a single in vitro study, where doxycycline inhibited CYP3A4-mediated metabolism of quinine to 3-hydroxyquinine.”

Inhibit 3A4 and Rapa levels rise…

Should you get s/s of an infection near the trough then, ok if you withhold the next rapa dose…but having s/s of an infection and then ^ the effect of Rapa… I don’t think that’s wise.

Realize that especially 3A4 can be problematic if you take an inhibitor, not so much if you take an inducer since the Rapa levels will drop.

Twice in my life I’ve been adversely affected by 3A4. The first time I was on Prozac and I learned that I simply do not have a very active 3A4, so my blood levels rose to toxic levels and I ended up in ED.

The 2nd time I was on Simvastatin and was prescribed by a doc erythromycin and developed rhabdomyolysis in less than 48 hours, had I “toughed it out,” and took another dose of erythromycin I’d be taking sirolimus not for aging but to prevent rejection of my new kidney. That was a combination of having a weak 3A4 + a strong inhibitor.

Interestingly, I later found that the exact same thing happened to my niece from Prozac and in both our cases then, it was not an inhibitor, it was just that we seem to have a weak 3A4.

Thus, I’ll be very slow in ^ my Rapa dosage and will rely on testing.

cyp3a4.pdf (120.1 KB)


This might be helpful to some, or just something to think about…

Strong inhibitors of CYP3A4 that one might not suspect: Green tea extract, Grape seed extract, Dillapiole (found in dill plants), and Apigenin (found in celery, parsley and chamomile)

Moderate inhibitor: Valerian

Weak inhibitor: Azithromycin; Berberine; Quercetin, amlodipine (which I take for BP)

Unknown: cannabidiol (for you potheads😊) niacin and piperine

From Wikipedia

CYP3A4 - Wikipedia(abbreviated%20CYP3A4,be%20removed%20from%20the%20body.

a Strong inhibitor causes at least a 5-fold increase in the plasma AUC values, or more than 80% decrease in clearance.[38]

a Moderate inhibitor causes at least a 2-fold increase in the plasma AUC values, or 50–80% decrease in clearance.[38]

1 Like

Then I’ll have to go back to my previous position that ALL ANTIBIOTICS ARE BAD.

A single in vitro study doesn’t provide much. There’s scant information in the literature regarding doxycycline and CYP3A4 inhibition despite over eight million prescriptions for this drug every year in the US alone. About 50% of medications are actually metabolized through the CYP3A4 enzyme, meaning that doxycycline is regularly prescribed for people on other medications metabolized through that enzyme without drug interactions noted in most cases. Medscape does note a few exceptions where it’s recommended that doxycycline be avoided for this purpose out of caution. So you are correct that in theory it may increase rapamycin levels. How much is another story. If you found out that it led to say, a 6% difference would that matter to you? There are weak inhibitors, moderate, and strong inhibitors of this enzyme. Just the meal that rapamycin is taken with can affect the absorption by up to 35%. And we only take rapamycin once weekly, not daily. Doxycycline has been used in multiple published studies to treat infections and inflammation in patients taking higher doses of sirolimus on a daily basis for immune suppression. (1),(2)