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Hepatitis C Main Forums => Post Hepatitis C Treatment => Topic started by: prston on June 03, 2018, 12:52:09 pm

Title: URGENT: Has Anybody Taken Strong Antibiotics WITH Harvoni?
Post by: prston on June 03, 2018, 12:52:09 pm
HELP!  I developed a severe complication in my 4th Week of Harvoni that threatens my treatment.  (Started 5th week today.)

Can anybody answer these questions:

1.  Did you take any antibiotics along with Harvoni?  (Specifically, CLINDAMYCIN.)
2.  If so, did you suffer any side effects by taking antibiotics with Harvoni?


In the 3rd week of Harvoni, an abscessed tooth presented itself (along with extreme pain).   A severe gum infection followed.

My family dentist was too spooked to treat me after I mentioned taking Harvoni (he worried about incompatible reactions with his dental meds & Harvoni).  I was pawned off to a Periodontist.

I reported to my Hep C doctor....who immediately sent me to the lab for blood work.

The blood test showed my liver enzymes were nearly normal but my white blood count was 'astronomical'.   He was very concerned.

The Periodontist said he couldn't treat me until the infection was under control.

I was prescribed the antibiotic CLINDAMYCIN 150mg, 2 pills per dose, 3 doses per day.

My Periodontist said he didn't know if the antibiotic or his dosage was compatible with Harvoni.   

I started yesterday.  I woke up today with a bad gut ache (on top of the Harvoni side effect of nausea  :P).

I called Harvoni's Nurse Hotline...and only got a lawyer-like answer saying there was 'no known' issues with that specific antibiotic, but there were no clinical studies testing Harvoni with said antibiotic.   Basically, the answer was:  Gilead didn't really know. 


Thank you, Preston
Title: Re: URGENT: Has Anybody Taken Strong Antibiotics WITH Harvoni?
Post by: badbradley on June 04, 2018, 12:02:15 am

   I found this info regarding the drug compatibility issue. Hope it helps

Per  Harvoni prescribing information sheet.
5.3 Risk of Reduced Therapeutic Effect Due to Use with P-gp Inducers
The concomitant use of HARVONI and P-gp inducers (e.g., rifampin, St. John’s wort)
may significantly decrease ledipasvir and sofosbuvir plasma concentrations and may
lead to a reduced therapeutic effect of HARVONI. Therefore, the use of HARVONI with
P-gp inducers (e.g., rifampin or St. John’s wort) is not recommended [see Drug
Interactions (7.2)].


In conclusion, the current in vitro findings show that the antibiotic clindamycin appears to be oxidized primarily by CYP3A4 (Fig. 8). Moreover, it appears that clindamycin does not inhibit the metabolic activity of the following P450 enzymes, CYP1A2, CYP2C9, CYP2C19, CYP2E1, and CYP2D6, and only moderately inhibited CYP3A4. Therefore, given the poor affinity toward the human hepatic cytochrome P450 enzymes tested, clinically important interactions between clindamycin and coadministered drugs, which are metabolized by these enzymes, appear unlikely.


Effects of DAAs on CYP3A4 substrates
Sofosbuvir and ledipasvir are not metabolised by CYP3A4 37. Ledipasvir is slowly metabolised via an unknown mechanism 21 (Table 1). Sofosbuvir and ledipasvir have been tested in healthy volunteers with cyclosporine, tacrolimus, methadone, ethinyl oestradiol, all substrates of CYP3A4, without clinically significant interactions as expected (Tables 3-5) 28, 39, 42.

This is a great tool to have

Summary: Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Clindamycin is metabolised by CYP3A4 but ledipasvir is only a weak inhibitor of intestinal CYP3A4 in vitro.

It appears you've got the all clear.
Title: Re: URGENT: Has Anybody Taken Strong Antibiotics WITH Harvoni?
Post by: prston on June 04, 2018, 11:52:54 am
@ BadBradley

Goodness, you provided much better info than my Hep doctor, Periodontist, and the Harvoni Nurse Hotline.

Thanks to your info, I can make an informed decision about taking strong antibiotics with Harvoni.

You put a lot of effort into your answer.  God Bless You for helping a stranger.  You're aces!

With my deepest appreciation, Preston
Title: Re: URGENT: Has Anybody Taken Strong Antibiotics WITH Harvoni?
Post by: Lynn K on June 04, 2018, 01:12:39 pm
Great answer badbradley very through!