Prezista Dosing

[gemini20]

I'm just curious to know what dosage of Prezista anyone else is taking.

I know that the recommended amount is 2 x 300mg twice a day but when my doctor put me on it back in October he told me to take 3 x 300mg once a day which is what I have been doing with the Ritonavir (Norvir) booster.

I've been doing this PI only regime for six months now and am due back at my doctor's next Friday to see what the latest numbers are and I was wondering whether I should query his dosing regime? That being said it might be immaterial if I choose to take another break from meds again.


Thanks to any fellow Prezista users for any feedback.


Emma

[AndyArrow]

I can't give you and real insight but I'm on the traditional 2 x 300mg twice a day. I was in poor health when I started this regimen. Maybe he has found good results and better adherence with a once a day dosing.

I would think how you are feeling and your lab results since starting back on it would be a good indicator.  If it's working thats great.  Less pills to remember to take.

Just my thoughts and I'm certainly no expert. 

AA

[newt]

The approved dose of Prezista is indeed 600mg (plus ritonavir) twice daily.

The ARTEMIS study compared 800 mg Prezista plus 100 mg (+ ritonavir) once daily to Kaletra once or twice daily and got good/equivalent results. This was the PI + 2 nukes.

Hence probably the 900mg dose, because with the tablets available you can't prescribe 800mg in the UK, 900mg is the nearest, only the 300mg tabs are available to clinics.

The test in the end, in terms of whether 900mg is working, is your viral load. Side effects might be better (if you have them) 2 x day but adherence/getting on with life may be better 1 x day....

All the best to you, Spring is here, April showers, evening sun, lunchtime rain, my cat on the prowl...

- matt

[Tim Horn]

Emma:

That is an interesting dosing recommendation, to be sure. Only one study involving treatment-experienced patients looked at Norvir-boosted Prezista dosing at 100/900mg once daily -- but that study only lasted 14 days. It was the twice daily 100/600mg dose that proved to be the safest and most effective in treatment-experienced patients.

Not knowing your treatment history, perhaps you have very few HIV mutations to protease inhibitors and your doctor is attempting to treat you with a dose that's more along the lines of the one that's being studied in the ongoing ARTEMIS clinical trial involving treatment newbies? In this study, the dose is 800mg Prezista boosted with 100mg Norvir, taken once a day. And because we only have 300mg tablets of the drug available through pharmacies -- a 600mg tablet version will be hitting pharmacy shelves next month, but that's another issue -- your doctor may be rounding your daily dose up, just to be on the safe side.

If you're seriously treatment experienced and using Norvir-boosted Prezista after failing other protease inhibitors in the past, there's really not nearly enough evidence to suggest that this dosing schedule is what you need to keep your viral load under control. If, however, you're in the earlier stages of HIV treatment, you're problaby getting a little bit more drug than you actually need... but perhaps not dangerously so.

Very chic and forward-thinking HIV treatment -- obviously, the best person to discuss this unorthodox dosing with is your prescribing health care provider.

Tim Horn

[Tim Horn]

In other words, what Newt says.

[gemini20]

Thanks guys that's been really helpful - I didn't know about the Artemis study so will check that out.

For Tim's benefit - I've been through 9 different drugs in 5 different treatment regimes so I guess I fall into the treatment experienced category. My doctor has never mentioned anything about mutations so I don't know if I have any of those.

I have always had a relatively low viral load even before treatment - averaging about 12,000; when I restarted meds in October my viral load was only 4,402 even though t-cells were down at 112 and I'd been off meds for 18 months. It took 3 months to get undetectable and that's where it currently is.

Knowing my adherence issues I'm sure my doctor took that into consideration when suggesting a once a day regime - that hadn't occurred to me before!

Very chic and forward-thinking HIV treatment.

Tim Horn

That would definitely be a description of the way my doctor works!


Emma

[newt]

ARTEMIS write-ups here:

http://www.natap.org/2008/CROI/croi_29.htm

http://www.i-base.info/htb/v8/htb8-11-12/Darunavir.html

- matt