Back to the Top
Dear Friends
In a PK oral drug-drug interaction study of drug A with B; the A showed significant decrease in some
parameters like Vd CL and MRT etc. but after multiple dose of B, the difference is still
significant when A was administered alone low but are higher than the single dose. I wonder how to
explain it. The drug B is omeprazole.
Dr.Zafar Iqbal
Department of Pharmacy
University of Peshawar
Back to the Top
Dr. Iqbal,
The interaction after a single dose vs multiple dosing could be via different mechanisms. CYP
inhibition would occur faster than induction, and omeprazole is a mixed inhibitor and inducer of
various CYPs.
Parag Kumar, PharmD
Back to the Top
Hi Dr. Iqbal,
You can study the PK of drug A during the washout period of omeprazole to eliminate inhibitory
effect of the proton pump inhibitor. As mentioned by Parag omeprazole interferes with activity of
many cytochrome P450 enzymes for example it induces CYP1A while inhibits CYP2C19 and CYP2D6
isoforms. Inhibitory effect will not be seen during washout period (or will be minimized depending
on the time), but inducing effect will be observed for few days after stopping treatment of
omeprazole. Inducing effect will last longer than inhibitory effect.
Thanks,
Sumanta Kumar Goswami, Ph.D.
Back to the Top
Dear Friends
We are working drug-drug interaction and drug food interaction of drugs available in the market in
Healthy Human volunteers. The titles of the projects are approved by the institutional Ethical
Committee. Do we need the Registration of the Clinical Trial with WHO?
Dr .Zafar Iqbal.
Meritorious Professor
Department of Pharmacy
University of Peshawar
Back to the Top
Are you testing a new molecule on patients, is my first question. You have to register then. Even
then you have to register any human related studies with IEC.
Back to the Top
These are not new molecules already prescribed medicines.
Dr .Zafar Iqbal.
Meritorious Professor
Department of Pharmacy
University of Peshawar
Back to the Top
Also, what methods do you plan to use to achieve your desired DDI? You might look at Jelliffe R:
Commentary - Optimal Methodology is Important for Optimal Pharmacokinetic Studies, Therapeutic Drug
Monitoring, and Patient Care. Clinical Pharmacokinetics. (DOI) 10.1007/s40262-015-0280-4.
Very best regards,
Roger Jelliffe
Back to the Top
registering with local IEC is enough, that would help you to publish results with WHO
--
Gayathri
Back to the Top
Dear Roger,
We are using two sequence two period cross over design
Dr .Zafar Iqbal.
Meritorious Professor
Department of Pharmacy
University of Peshawar
Back to the Top
Dear Dr. Iqbal:
I do not mean clinical trial design. I mean how do you plan to obtain and analyze your data?
Please look at the reference I suggested.
Very best regards,
Roger Jelliffe
| PharmPK Discussion List Archive Index page |
Copyright 1995-2014 David W. A. Bourne (david@boomer.org)