MEDfacts

POCKET GUIDE OF DRUG INTERACTIONS

Second Edition

Provided as an Educational Service by



MEDfacts


POCKET GUIDE OF
DRUG INTERACTIONS

Second Edition

This drug interactions pocket guide was written on behalf of Nephrology
Pharmacy Associates, Inc. (NPA) by George R. Bailie, PharmD, PhD,
Curtis A. Johnson, PharmD, Nancy A. Mason, PharmD, and
Wendy L. St. Peter, PharmD, BCPS.


NPA acknowledges the assistance of Fangyan Sy, PharmD.



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Disclaimer

These drug interaction guidelines are offered as a general summary of
information for physicians, pharmacists, nurses and other health professionals.
Inappropriate administration of interacting drugs to patients can result in severe
injury or death. These guidelines cannot identify medical risks specific to an
individual patient or recommend patient treatment. These guidelines are not to
be used as a substitute for professional training. The absence of typographical
errors is not guaranteed. These guidelines are not necessarily all-inclusive.
Use of these guidelines indicates acknowledgement that neither Nephrology
Pharmacy Associates, Inc. (NPA), Bone Care International, Inc. nor the
authors will be responsible for any loss or injury, including death, sustained
in connection with, or as a result of, the use of these guidelines. Readers should
consult the complete information available in the package insert for each agent
indicated before prescribing medications.

Guides such as this one can only draw from information available at the time
of publication. Nephrology Pharmacy Associates, Inc., Bone Care International,
Inc. and the authors of these guidelines are under no obligation to update
information obtained herein. Future medical advances or product information
may affect or change the information provided. Health professionals using these
guidelines are responsible for monitoring ongoing medical advances related to
drug therapy.

Copyright 2004. All rights reserved, including right of reproduction, in whole or in
part, in any form.


MEDFACTS POCKET GUIDE OF DRUG INTERACTIONS / 3

Preface

Patients with acute renal failure, chronic kidney disease (CKD) or those treated
with dialysis or kidney transplantation are frequently prescribed numerous
medications. Drugs of many therapeutic classes are used to treat the underlying
diseases leading to CKD, such as diabetes mellitus and hypertension, while
others are used to control or treat the common complications of CKD, such
as anemia, renal bone disease and lipid disorders. Dialysis patients often are
prescribed 10 to 12 medications. With such a large number of medications, there
is an increased risk for drug interactions. The accompanying table has been
prepared as a reference regarding the most clinically significant drug
interactions that might occur, together with an indication of the possible
consequence. This table should be used as a general guideline.

Sometimes information is known about one specific drug within a certain drug
class, while additional information is not known about other agents within the
same therapeutic category. Clinicians must be aware of this possibility and use
their best judgement when prescribing or assessing drug therapy.

Types of Drug Interactions

Drug interactions are often classified as either pharmacodynamic or
pharmacokinetic interactions. Pharmacodynamic interactions include those
that result in additive or antagonistic pharmacological effects. Pharmacokinetic
interactions involve induction or inhibition of metabolizing enzymes in the liver or
elsewhere, displacement of drug from plasma protein binding sites, alterations
in gastrointestinal absorption, or competition for active renal secretion.

The frequency and prevalence of interactions is dependent upon the number
of concomitant medications and the complexity of the regimens. The prevalence
is also dependent upon other variables, such as patient adherence, hydration
and nutritional status, degree of renal or hepatic impairment, smoking and
alcohol use, genetics and drug dosing. Additionally, some patients may exhibit
evidence of a particular drug interaction, while others with the same drug
combination do not.


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Pharmacodynamic interactions

This type of interaction will not be addressed in this reference, since these