Drug handbooks for personal digital assistants (PDAs): a comparison of ePocrates Rx Formulary, Lexi-Drugs Platinum, mobileMICROMEDEX, and Tarascon ePharmacopoeia

ePocrates Rx Formulary. Version 5.5. ePocrates, 120 Industrial Road, San Carlos, CA 94070; 650.592.7900. http://www.epocrates.com. See Table 3 for price information and system requirements.

Table 3 PDA drug handbooks: compatibility and suitability

Lexi-Drugs Platinum. ISBN 1-930598-78-5. [File date Mar 31, 2002]. Lexi-Comp Reader (application viewer). Version 1.2011206. [File date: Mar 31, 2002]. Lexi-Comp, 1100 Terex Road, Hudson, OH 44236; 800.837.5394. http://www.lexi.com. See Table 3 for price information and system requirements.

mobileMICROMEDEX. Version 112. [File date: Mar 22, 2002 (Edition expires Jun 30, 2002)]. MICROMEDEX, 6200 South Syracuse Way, Suite 300, Greenwood Village, CO, 80111-4740; 800.525.9083. http://www.micromedex.com. See Table 3 for price information and system requirements.

Tarascon ePharmacopoeia. Version 1.6.04, 04-04-2002. ISBN: 1-882742-15-X. Green, Steven M, editor-in-chief. Tarascon Publishing, P.O. Box 1159, Loma Linda, CA 92354; 800.929.9926; http://www.tarascon.com. See Table 3 for price information and system requirements.

Current pricing and performance levels for personal digital assistants (PDAs), also known as handheld or palmtop devices, have made them an ideal platform for electronic reference materials. Several companies have created PDA-based drug handbooks. These handbooks allow instant access to detailed drug information and drug interactions from anywhere [1]. They also make possible other features only practical with electronic media, such as fast updates, user customization, and electronic information transfer.

Drug handbooks that have been created for use on PDAs include ePocrates Rx Formulary, Lexi-Drugs Platinum (General view, Essential version reviewed here), mobileMICROMEDEX, and Tarascon ePharmacopoeia. A drug database identical to ePocrates RX Formulary but without the formulary, called ePocrates Rx (formerly qRx), is available [2]. All of these run on the ubiquitous Palm OS. The core functionality of all is very similar. They provide easy access to drug monographs that provide dosing, adverse effects, and other information. Several also provide a drug-interactions tool. Each package also includes several special features.

Drug monograph access

Drug names are listed in an alphabetical index in each of the handbooks. To access a drug monograph, one simply looks in the index under either generic or trade name.

Each handbook allows for searches by drug class. The handbooks vary more in class-based searching than in drug name–based searching. Two of the handbooks, ePharmacopoeia and ePocrates, take a hierarchical approach, requiring one to begin at a broad category and narrow to more specific classes. To search for muscle relaxants, for example, one begins with the broad class, “Analgesics,” next chooses “Muscle Relaxants,” and finally chooses from a list of specific drugs. In contrast, Lexi-Drugs and mobileMICROMEDEX take a specific approach, having one search directly for the narrower drug class. Lexi-Drugs allows for more flexibility, offering various entry points for muscle relaxants, including “Muscle Relaxant,” “Skeletal,” and “Skeletal Muscle Relaxants,” and mobileMICROMEDEX offers only one preferred entry, “Skeletal Muscle Relaxant.”

Drug monograph entries

In ePocrates after a trade name lookup, a trade name monograph appears that includes the generic name. For generic name lookups, the message “drug exists as multiple brands and/or as a generic drug” generally appears with selection choices. In Lexi-Drugs and ePharmacopoeia, searching for either generic or trade names results in a generic monograph with brand names listed. The mobileMICROMEDEX handbook is unique in that the entered drug name (either generic or trade name) is listed at the top of the monograph display, followed by generic names, common tradenames, and remaining details.

Three products—ePocrates, Lexi-Drugs, and mobileMICROMEDEX—are quite similar in layout and navigation. In addition to scrolling, they all provide “jump to” navigation using popup menus. In contrast, ePharmacopoeia's concise screen layout is divided into three parts: a “codes” area, a center display area, and a “selection” area with tabs (adult, peds, forms, and notes) or icons (custom notes or skull and crossbones). Table 1 provides a quick summary of the elements included in each drug handbook's monograph.

Table 1 PDA drug handbooks: comparison of drug monographs

Drug interactions tool

A feature that is often either included in a PDA drug handbook or available separately is a drug-interactions tool. Such tools permit one to enter several drugs and check for interactions. A less desirable alternative would be reading the monograph for each drug. MultiCheck, ePocrates's drug interactions tool, is built into the application as a pull-down menu. When one selects two or more drugs, such as aspirin and Coumadin, the display shows “aspirin ↔ Coumadin” with a popup menu detailing the interaction.

The tool for mobileMICROMEDEX works in the same way but is more intuitive with its two descriptive buttons, “Check” and “Clear All.” Its tool presents an immediate display summarizing the interaction with a “More Information” button.

Special features

Several of the handbooks include the ability to attach custom notes to the drug monographs. These notes can be beamed to other PDAs. A number of the handbooks include additional reference material. Two handbooks, ePocrates and ePharmacopoeia, include a table of inhaler colors. Both also include additional reference material. Several handbooks allow one to create personal lists of drugs. The ePocrates handbook has the ability to work with formularies. Many insurance companies have provided their formularies for this handbook.

Another ePocrates product is ePocrates ID, an infectious diseases database. This product, formerly named qID, links with the ePocrates drug handbook [3]. The mobileMICROMEDEX data manager provides linking to MICROMEDEX's other medical databases. Table 2 provides a quick guide to some of the special features in each drug handbook.

Table 2 PDA drug handbooks: comparison of special features

Relative strengths

Each of the handbooks has features that make it a better choice for certain environments. Lexi-Drug's strength is in the quantity of brand names, including nonprescription, over-the-counter drugs (OTCs). Lexi-Drug's use of the label “[OTC]” following the drug name in the lookup indexes is a useful addition. The strength of ePharmacopoeia lies in its screen layout and the ability to get a snapshot of just essential information. As one quickly becomes familiar with the simple graphics and abbreviations in ePharmacopoeia's codes section, one recognizes how valuable this shorthand communication is. The skull and crossbones icon is a universal symbol and an excellent choice to call attention to black box warnings.

A unique strength of mobileMICROMEDEX is the integration of several additional medical applications using the mobileMICROMEDEX Data Manager. In addition to the drug database and drug interactions tool, there are acute care, alternative medicine, and toxicology databases.

Both ePocrates and ePharmacopoeia include tables, although the designation is a misnomer, because the data are not presented in tabular format. The tables in ePharmacopoeia are easily found on the startup screen, whereas ePocrates' tables are hidden in the drug name index under “Table.”

The standard for currency is shifting. Both ePocrates and Lexi-Drugs provide daily updates, and Tarascon has projected ePharmacopoeia will soon follow. In terms of updating ease, ePocrates's AutoUpdate function currently has no competition. While Lexi-Drugs also provides daily updates, more effort is involved. One must link to the Lexi-Drugs Website, log in, and then get the current update.

The drug-interactions tools in ePocrates and mobileMICROMEDEX simplify the task of determining whether or not medications can be taken together. The information provided by mobileMICROMEDEX's drug-interactions tool is more detailed than ePocrates's tool. Having formularies sets ePocrates apart from the others. It allows one to check which drugs are covered by a particular plan, determine which require prior authorization, and find therapeutic alternatives. Unfortunately, the formularies are only available in selected geographic areas; they are being launched on a state-by-state basis.

Handbook selection

In addition to considering which handbook is best for a particular environment, it is important to consider the compatibility of the handbook with each PDA:

• Is the handbook available for the device (i.e., Palm OS or Pocket PC)? Examples of Palm OS handheld devices include Palm, Handspring, Sony Clie, and TRG/Handera. Examples of Pocket PC (Windows CE) handheld devices include Casio CASSIOPEIA, Compaq iPAQ, and HP Jornada.

• If the device is not brand new, is the handbook available for older versions of the OS?

• Does the device have sufficient available memory?

• Evaluate the product's suitability: Is it authoritative? Is it kept current? If it is not free, is it worth the purchase price?

Table 3 summarizes some of these factors.

A final consideration must be a careful review of any disclaimers and privacy issues with regard to the product. Like an Internet browser, any PDA application that connects with a remote site may send data, such as usage-tracking information, back to sites without notifying users [4].