Re: [NMusers] NONMEM/PsN benchmark for SGE expansion

Hi Julia, On 3/25/2011 4:42 PM, Ivashina, Julia wrote: * What type of analysis is the most sensitive to an increase in number of work nodes? As far as I know, the version of nonmem that you have installed does not support parallel processing. Legend has it that this feature will sho

RE: [NMusers] Time-to-event analysis with $DES

Hi All I would just like to point out that in the Weibull hazard that Nick proposes: HAZNOW=LAMD*ALPH*(TIME+DEL2)**(ALPH-1) The units of LAMD would have to be TIME**(-ALPH). That is, as soon as ALPH changes then the units of LAMD change. This seems strange and unnecessary to include t

Re: [NMusers] Time-to-event analysis with $DES

Andy, Thanks for this response. In fact I did not propose that particular Weibull parameterization but simply pointed out that it seemed to be what the original questioner seemed to be trying to use. My own preference for parameterizing the Weibull is HAZARD=LAMDA0*EXP(BETA*LOG(TIME)) Th

[NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear All, I am working on a Pop PK data where the patients are treated with HIV drug. An autoinduction is involved with prolonged administration of the drug. An increased CL is expected from day 1 to day 14. We have intense data on day 1 and day 14 with sparse data between. Since a lag period is i

RE: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Shankar, How rich is your dataset? In other words: do you have enough data troughout the induction period to estimate the lagtime? You could, for example try to fix the lagtime to a reasonable time and estimate the inter-individual variability. Another way of estimating the autoniduction is

Re: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Shankar, A couple of thoughts that may help. (1) If the model is terminating with a note that states something along the lines of 'Infinite value of objective function', this indicates that the estimated value of TLAG for an individual is occurring at the time of a sample. Potential solutio

Re: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Rob ter Heine, I am working with Efavirenz, I working with 66 patients, 924 data points, intense on day 1 and 14 and a trough con in between the two weeks. I looked into the Physiological model presented by Dr. Karlsson earlier but I did not used it since I dont have any information about E

RE: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Shankar, I would guess that it is the term (t-tlag) which is negative in your code as long as tmailto:owner-nmus...@globomaxnm.com] On Behalf Of Shankar Lanke Sent: den 28 mars 2011 15:53 To: nmusers@globomaxnm.com Subject: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Re: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Philips, Thank you very much for your input, I am re-parameterizing the model now. I will run this model and update you soon. Regards, On Mon, Mar 28, 2011 at 10:48 AM, Luann Phillips < luann.phill...@cognigencorp.com> wrote: > Shankar, > > A couple of thoughts that may help. > > (1) If t

Re: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Alice, I reduced the number of eta's too but I didnt removed on induction. My S3=V2, Vd is in mg/L so there are no issues with unit transformations. I agree with your suggestion, I will removed eta on induction model and I will fix the induction parameter. Thank you very much for your time

Re: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Hi Shankar, We published an autoinduction model a few years back (Gordi et al., Br J Clin Pharmacol. 2005;59(2):189-98). The original paper was based on saliva samples but the model worked well using plasma data (Asimus and Gordi, Br J Clin Pharmacol. 2007;63(6):758-62). We also used it to desc

Re: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Shankar, In addition to what's been already said, you have a couple of problems in your code. ALAG1 is a reserved name in NONMEM. You use it as 1/Ktransit for your transit absorption compartment. But NONMEM also uses it to delay a dose entering  compartment 1 by ALAG1 time. The second pro

Re: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Toufigh, Thank you very much for your email, there is wealth of information you have provided me, I will look carefully into your suggestions and I will my model soon. Once again I appreciate your input. On Mon, Mar 28, 2011 at 12:51 PM, Toufigh Gordi wrote: > Hi Shankar, > > We published

RE: [NMusers] Time-to-event analysis with $DES

Hi Nick, Andy, The Weibull hazard is not necessarily my first choice either. However, I should point out that it is not a much of an issue that the Weibull predicts a zero hazard at time 0 (only defined for ALP>1). One typically assumes the survival fraction is = 1 at time = 0, so it doesn't

RE: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Shankar, You don't need to have information about enzyme levels or precursor to use the model mentioned by Rob, the idea of it is only to have a more physiological mechanism for the delay (not a lag but something that develops with a first-order delay) and magnitude (which is dependent on

Re: [NMusers] Autoinduction model - An increased clearance(day 1- 14)

Dear Dr. Karlsson, Thank you very much, I will apply the enzyme model for Auto Induction as described Hassan et.al earlier. I appreciate your feed back. Once again Thank you very much Rob Ter Heine. On Mon, Mar 28, 2011 at 6:03 PM, mats karlsson wrote: > Dear Shankar, > > > > You don’t need t