Blog > Apple Core Labs, LLC

Become a Fan!

noreply@blogger.com (Rob) — Sun, 28 Feb 2010 17:31:00 +0000

Not only do we have a Twitter page, we now have a Facebook page. Head on over and become a fan! We'd love for you to share your stories or post a picture.

Let's have some fun!

Relief for Haiti, update

noreply@blogger.com (Rob) — Thu, 21 Jan 2010 16:42:00 +0000

Good morning! It looks like yesterday's Indie+Relief effort was a huge success! Even though we blew it and didn't get in on the official program we decided to do what we could. We're sending $50.00 to Doctors without Borders in the name of our users. We'd like to extend our whole hearted thanks to everyone that participated in the various efforts around the Mac Indie scene yesterday.

We're very small, and the dollar amount we're sending seems small, but every little bit helps.

THANK YOU!

Relief for Haiti

noreply@blogger.com (Rob) — Tue, 19 Jan 2010 20:05:00 +0000

The Mac and iPhone Indie community have put together a relief effort for Haiti called Indie+Relief, brought to you by Second Gear Software and Garrett Murray. Apple Core Labs tried to participate but we were just too late due to an overwhelming response, and our lateness to join the effort. Fear not! We're going to join the effort, just not through Indie Relief.

What does that mean?

Quite simply this. Apple Core Labs will donate all proceeds from sales of RxCalc on January 20, 2010 to Doctors Without Borders to help the people of Haiti.

If you've ever considered purchasing RxCalc now would be a great time to give it a try and in the process you'll help people in need.

Also, while you're here, take a look at all the great software being offered by Indie Relief, and pick something else up to help fight the good fight!

Thank You.

Evaluation of once-daily gentamicin dosing in children with febrile neutropenia

noreply@blogger.com (Jerry) — Sat, 02 Jan 2010 16:15:00 +0000

Once-Daily Gentamicin Dosing in Children with Febrile Neutropenia Resulting from Antineoplastic Therapy

Miriam Inparajah, B.Sc.Phm. | Cecile Wong, B.Sc.Phm. | Cathryn Sibbald, B.Sc.Phm. | Sabrina Boodhan, B.Sc.Phm. | Eshetu G. Atenafu, M.Sc. | Ahmed Naqvi, M.B.B.S., MCPS, MRCP | L. Lee Dupuis, M.Sc.Phm., FCSHP

Pharmacotherapy. 2010 Jan;30(1):43-51

Abstract

Study Objectives. To evaluate an existing once-daily gentamicin dosing guideline in children with febrile neutropenia resulting from antineoplastic therapy and, if necessary, to develop a new simulated dosing guideline that would achieve pharmacokinetic targets more reliably after the first dose.

Design. Pharmacokinetic analysis of data froma retrospective medical record review.

Setting. Hematology-oncology unit of a university-affiliated pediatric hospital in Canada.

Patients. One hundred eleven patients aged 1–18 years who received once-daily gentamicin between April 2006 and January 2008 for the treatment of febrile neutropenia resulting from antineoplastic therapy, and who had plasma gentamicin concentrations determined after their first dose.

Measurements and Main Results. Demographic data, gentamicin dosing information, blood sampling times, and plasma gentamicin concentrations were noted. Plasma gentamicin concentrations were determined at approximately 3 and 6 hours after the start of the 30-minute infusion of the first dose. Pharmacokinetic parameters were calculated according to standard first-order, one-compartment equations. The proportion of children who achieved pharmacokinetic targets after the first gentamicin dose was used as a measure of dosing guideline performance; the guideline achieved maximum concentration (Cmax) values below the target range (20–25mg/L) in 51% of patients. Ideal dosing guidelines were then developed using the mean dose required to achieved a Cmax of 23 mg/L for each patient. Univariate analysis or the Student t test was used to determine the existence of significant relationships between pharmacokinetic parameters and patient age and sex. The recursive binary partitioningmethod was used to determine critical values of age for dosage guideline development; analysis of variance was then used to compare the different levels obtained after use of this technique. Simulated administration of once-daily gentamicin in the following doses achieved a Cmax within or above target in 73% of patients: 1 year to 6 years, 10.5mg/kg/dose; girls ≥ 6 years, 9.5mg/kg/dose; and boys ≥ 6 years, 7.5mg/kg/dose. Doses were based on actual body weight for children who weighed less than 125% of ideal body weight or based on effective body weight for children 125%ormore of ideal body weight.

Conclusion. The initial gentamicin dosing guidelines were not effective in achieving Cmax. The new proposed dosing guidelines are predicted to achieve a Cmax within or above the target range in almost three quarters of patients. Subsequent dosing should be tailored according to plasma gentamicin concentrations.

Got Pharmacokinetics?

noreply@blogger.com (Rob) — Thu, 31 Dec 2009 18:34:00 +0000

The year is coming to an end, so why not celebrate by purchasing a copy of RxCalc for your iPhone? There's still time to buy before the end of the year and at $0.99 it's a real bargain! At least we think it is.

So, what do you get for less than a buck?

New Start - Vancomycin and Aminoglycoside.

Adjustment with Levels - Vancomycin and Aminoglycoside.

Ideal Body Weight

Creatinine Clearance (CG)

That's just the 1.0 release. We have more features planned for the next release and we'd LOVE to hear from our users, just drop us an e-mail at support@applecorelabs.com, it's that easy.

If you'd like more information on RxCalc, just visit the RxCalc product page. If you'd like to purchase RxCalc, visit the iPhone App Store.

Best iPhone Apps for Pharmacists

noreply@blogger.com (Rob) — Sat, 05 Dec 2009 13:48:00 +0000

Online Education Blog: "This application is said to be the only pharmacokinetics calculator made available on the iPhone. The handy interface helps the end user enjoy a hassle free way of going about information collection." - Thanks for mentioning us!

Summary of Consensus Recommendations for Vancomycin Monitoring in Adults

noreply@blogger.com (Jerry) — Sun, 01 Nov 2009 00:32:00 +0000

A recent article in November 2009 issue Pharmacotherapy summarizes the recommendations from the American Society of Health-System Pharmacists, the Infections Diseases Society of America, and the Society of Infectious Diseases Pharmacists on the monitoring of vancomycin in adults.

“The American Society of Health-System Pharmacists, the Infectious Diseases Society of America, and the Society of Infectious Diseases Pharmacists published a consensus statement on therapeutic monitoring of serum vancomycin levels in adults. These organizations established an expert panel to review the scientific data and controversies associated with vancomycin monitoring and to make recommendations based on the available evidence. As the members of this panel, we summarize the conclusions and highlight the recommendations from the consensus statement. We determined that the area under the concentration-time curve (AUC):minimum inhibitory concentration (MIC) ratio is the most useful pharmacodynamic parameter to predict vancomycin effectiveness and suggested a target ratio of 400 or greater to eradicate S. aureus. In addition, trough serum concentration monitoring is the most accurate and practical method to monitor vancomycin serum levels. Increasing trough concentrations to 15–20 mg/L to attain the target AUC:MIC ratio may be desirable but is currently not supported by clinical trials. Alternative therapies should be considered in patients with S. aureus infections that demonstrate a vancomycin MIC of 2 mg/L or greater because the target AUC:MIC ratio ( 400) is unlikely to be achieved in this setting. Increasing the dosage to result in higher trough concentrations may increase the potential for toxicity; however additional clinical experience is required to determine the extent.”

While the article contains nothing new in terms of vancomycin monitoring and kinetics, the recommendation to consider alternate therapy for S. aureus infections with an MIC >/= 2 mg/L is important to note.

RxCalc on Medgadget

noreply@blogger.com (Rob) — Wed, 09 Sep 2009 15:44:00 +0000

Medgadget: "Here's a new iPhone application for pharmacists that 'puts commonly used pharmacokinetic calculations in the palm of your hand.'" - Thank you Medgadget!

The RxCalc Promotional has come to an end

noreply@blogger.com (Rob) — Tue, 08 Sep 2009 04:37:00 +0000

Our "FREE for the day" event has come to a close.

Thanks very much for downloading RxCalc, giving it a spin, and pushing it to the #12 spot in the Medical Apps Category!

Based on the success of this event we're going to drop the price from $5.99 to $0.99!

I'd like to encourage those of you that took advantage of our little giveaway to please provide us with any feedback you may have, good or bad. We're committed to improving RxCalc so your feedback is important to us. So, please, drop us a line at support@applecorelabs.com, or one of our other contact addresses, let us know how RxCalc is working for you, and thank you for your continued support.

RxCalc One Day Blowout!

noreply@blogger.com (Rob) — Sat, 05 Sep 2009 14:26:00 +0000

In honor of Labor Day, Monday, September 7, 2009, we're going to offer RxCalc FREE for one day.

For 24-hours you'll be able to download RxCalc for nothing, so tell all your friends.

Don't forget, Monday, September 7, 2009 is RxCalc for free day!

Can antibiotic choice be based on MIC alone?

noreply@blogger.com (Jerry) — Tue, 18 Aug 2009 23:30:00 +0000

This questions was recently addressed by Michael J. Postelnick, Senior Infectious Diseas Pharmacist of Northwestern Memorial Hospital in Chicago, Illinois in an Ask-the-Experts post on the Medscape website. Postelnick gives a good explanation of how various pharmacokinetic and pharmacodynamic principles are related to antibiotic choice for infectious pathogens. According to Postelnick “research into antimicrobial pharmacokinetics and pharmacodynamics has established surrogate relationships between the 2 that correlate with outcomes such [as] bacterial eradication or clinical cure. These relationships include the ratio of Cmax to the MIC, time above the MIC (defined as the amount of time during the dosing interval that the antimicrobial concentration in the blood or at the site of infection remains above the MIC of the organism), and the ratio of the AUC to the MIC. For concentration-dependent antimicrobial agents such as fluoroquinolones and aminoglycosides, Cmax/MIC or AUC/MIC most closely correlates with clinical and microbiological outcomes. For time-dependent antimicrobial agents such as beta-lactams, the percentage of time during the dosing interval that the drug concentration remains above the MIC of the organism is the measure that most closely predicts outcomes.” In other words, selection of an antibiotic requires more than the MIC. Knowledge of the organism in addition to pharmacokinetic and pharmacodynamic principles of the drug is necessary to make an informed choice.

Vancomycin and nephrotoxicity in hospitalized patients

noreply@blogger.com (Jerry) — Wed, 05 Aug 2009 23:20:00 +0000

An article on the possible link between vancomycin trough concentrations and nephrotoxicity appears in a recent issue of Clinical Infectious Diseases (2009;49:507-14) . The article describes a retrospective study of 166 patients treated at Albany Medical Center Hospital in Albany, New York between January 2005 and December 2006. The study found that patients in the ICU, those with a weight of >/= 101 kg, and those with prolonged exposure to elevated vancomycin troughs (> 20mg/L) were associated with a greater risk for developing nephrotoxicity. The authors conclude that the vancomycin trough value was the parameter that best described this risk of toxicity. Based on this information, it appears that successful treatment of serious methicillin-resistant S.aureus infections with higher minimum inhibitory concentrations (MIC) may place patients at a greater risk for developing nephrotoxicity. The findings in the article are significant as recent guidelines recommend higher vancomycin trough concentrations for complicated S.aureus infections.

Although interesting and possibly informative, the information contained in the study is based on a small observational study in a single facility. The findings cannot necessarily be extrapolated to any significant degree to other patient populations and further studies are necessary to confirm the results on a larger scale. For now it appears that aggressive vancomycin therapy in addition to cautious monitoring of renal function and patient status is prudent when trough levels are approaching 20mg/L.

Why I wanted RxCalc

noreply@blogger.com (Jerry) — Thu, 30 Jul 2009 16:00:00 +0000

Cross-post from JerryFahrni.com. Jerry is our resident PharmD and co-creator of RxCalc.

I have a couple of passions when it comes to pharmacy. The first is a love of pharmacy technology. Very few pharmacists have an appreciation for the "operations" side of pharmacy which includes automated dispensing cabinets, automated carousels, automated TPN compounders, Pharmacy Information System, etc. These tools are absolutely necessary if we want to get pharmacists out of the physical pharmacy and at the bedside where they belong. My second passion is a little less known discipline known as pharmacokinetics. I have no idea why I like pharmacokinetics; I just do. Some kids like PB&J and some don’t. It’s just the way it is.
Vancomycin and aminoglycoside (especially vancomycin) pharmacokinetics are very popular in hospitals, and are part of a select group of drugs that physicians prefer pharmacists to handle. Doing pharmacokinetic consults isn’t difficult per se, but can involve lots of numbers and equations. Many people find it a bit tedious and boring. There is also considerable variability in methods used for performing pharmacokinetic calculations. For example there are several existing pharmacokinetic models for vancomycin including Bauer, Matzke, Winter, Moellering, etc. Some of the models are more popular than others, but each has merit. As I've heard many times, "there are many roads to Rome."
Pharmacists typically choose a favorite pharmacokinetic model and then alter the model to fit their needs based on years of clinical experience. I'm no different. Even though I was taught pharmacokinetics by Mike Winter at the UCSF School of Pharmacy, I prefer the vancomycin formulas derived by someone else. Please don’t tell Mike, he’s considered one of the best in the business and might revoke my alumni card if he found out.
Not all pharmacokinetic “starts” and adjustments require advanced calculations. Often times, years of experience and a good eye are all you need. However, there are times when you need a little more. Since the days of the Palm Pilot, I've always desired a portable pharmacokinetics program. It always made sense to me to use the technology at my finger tips to make my job easier. I've written several pharmacokinetic calculators, including simple Microsoft Excel spreadsheets and a little Java Script tied to a web front end, but I never got the opportunity to create a portable version. The iPhone (and iPod Touch) changed all that. The iPhone is a compelling device with a great user interface and unheard of popularity among healthcare professionals. My desire for a portable pharmacokinetics calculator, and the appearance of the iPhone, resulted in the creation of RxCalc.
RxCalc is designed for pharmacists based on my experiences over the past ten years. While not perfect, RxCalc does what I need. It’s clearly a work in progress. I don't use it all the time because it's simply not necessary. I still do a lot of “guess work” here and there, but rely onRxCalc when I need something to handle the more advanced calculations. Like every piece of software ever used, there is room for improvement. I have received lots of good, constructive feedback from several users. Combined with my desires, the feedback has created quite a list of future “enhancements” I’d like to see in RxCalc over the next several months. Among these include High Dose Extended Interval (a.k.a. once-daily) aminoglycoside dosing, single dose vancomycin kinetics, the option to change units (i.e. lbs, kg, cm, inches, etc), the ability to select different dosing models, alternate color schemes or themes and a more user friendly interface. Unfortunately, I don’t have the skill set to make the changes myself. That’s why God gave me a brother. I come up with the ideas and he does all the work to make it a reality. We make a great team.
I mentioned in a previous post that it may be time for me to put away my calculator in favor of newer technology. Pharmacokinetics was the last thing I really needed my calculator for. Well, with the creation of RxCalc I’ve finally put my calculator in the drawer and have been using pen, paper and my iPod Touch almost exclusively for a few weeks now. I must say, so far the results have been encouraging.

RxCalc 1.0.1 now available

noreply@blogger.com (Rob) — Thu, 30 Jul 2009 14:54:00 +0000

We've been sorting through some user feedback, it's great stuff! We noticed a recurring theme, "Why can't I make adjustments after my initial calculation on a New Start." We found that strange because you can definitely make adjustments after the initial calculation's are performed. So, we did a New Start, and it became quite obvious why people were confused. The results table fills the screen perfectly and there's no indication you should scroll down to make your adjustment!

So, we did a quick release to fix the problem. In 1.0.1 the screen will show and scroll to the bottom, where the adjustment fields are, right away. It's animated so you now know there's more data above if you're interested in viewing it. The critical data lies at the bottom of the screen; Tau and Estimated Dose, plus Desired Dose, Given Every, and Calculate. We hope this clears things up. (NOTE: The values used in the illustrations were NOT entered by a Clinical Pharmacist, or a healthcare professional. They are for illustration purposes only.)

Guidelines for Monitoring Vancomycin against Staphylococus aureus Infection

noreply@blogger.com (Jerry) — Thu, 23 Jul 2009 20:04:00 +0000

Medscape.com: "The Infectious Diseases Society of America, the American Society of Health-System Pharmacists, and the Society of Infectious Diseases Pharmacists have issued therapeutic guidelines for monitoring of vancomycin treatment for Staphylococcus aureus infection. The summary of consensus recommendations is published in the August 1 issue of Clinical Infectious Disease."

Some of the clinical recommendations include:

Dosing based on actual body weight, even for obese patients.
Measuring trough levels drawn just prior to the fourth dose.
Keeping trough concentrations greater than 10 mg/L and even higher, 15-20 mg/L, for complicated infections.
Consider alternate therapy for patients with CLcr 70-100 mL/minute and a targeted AUC/MIC > 400.

Additional clinical recommendations can be found in the guidelines, which are available for free in PDF format here.

Cockcroft-Gault remains standard for pharmacokinetic calculations, for now.

noreply@blogger.com (Jerry) — Thu, 16 Jul 2009 05:31:00 +0000

A recent article in Hospital Pharmacy presented a review of literature comparing various methods used for estimating renal function and how those equations are best used when applied to drug dosage adjustments. The article, "Drug Dosage Adjustment Using Renal Estimation equations: A Review of the Literature" discusses literature surrounding the Cockcroft-Gault (CG), the abbreviated Modification of Diet in Renal Disease equation (abbrMDRD), and to a lesser extent the original Modification of Diet in Renal Disease equation. Although promising, there simply isn't enough literature to support the use of the abbrMDRD equation in pharmacy practice. The article concludes that "although the abbrMDRD equation has many advantages as compared with the CG equation, too little research has been completed at this time to recommend the clinical use of the abbrMDRD equation in pharmacy practice."

RxCalc currently uses the Cockcroft-Gault equation to estimate renal function for all pharmacokinetic calculations. Apple Core Labs will continue to evaluate new and emerging data, and use this information to make changes to RxCalc when deemed appropriate.

All quiet on the western front

noreply@blogger.com (Rob) — Tue, 14 Jul 2009 18:02:00 +0000

Since the release of RxCalc on July 4th things have been pretty quiet around the labs. We've been working through our list of "love to have features" and have trimmed it down to a select few.

Now comes the hard part, actually doing the work, and delivering a new release.

If you're already using RxCalc you may be saying to yourself "Hey, I just bought a copy, what does that mean for me?" Good question! The answer is, you'll receive a free upgrade!

Thanks for supporting RxCalc, we really do appreciate it.

Going once, going twice...

noreply@blogger.com (Rob) — Tue, 07 Jul 2009 19:05:00 +0000

To help get the ball rolling on RxCalc we've decided to give away a few fully functional copies.

So, the first five healthcare professionals, or healthcare students, to e-mail their full name to us at support@applecorelabs.com, with the title "RxCalc Offer", will receive a promotional code that will allow you to download a copy of RxCalc from iTunes.

Yes, it's that simple.

We promise we won't give your e-mail address, or any personal information, to anyone.

Good Luck!

iPhone/iPod Touch required by PharmD program

noreply@blogger.com (Rob) — Tue, 07 Jul 2009 14:26:00 +0000

AppleInsider: "The University of Florida is the second school in as many months to announce that students enrolling in one of its curriculums this fall will be required to own either an iPhone or iPod touch, highlighting an increasing role for Apple's multi-touch devices in higher education." - RxCalc is a natural fit for the University of Florida's PharmD program!

Introducing RxCalc

noreply@blogger.com (Rob) — Sat, 04 Jul 2009 22:00:00 +0000

Apple Core Labs first iPhone/iPod Touch application, RxCalc, is now available on the iPhone App Store. RxCalc is a pharmacokinetics calculator designed to help pharmacists, and doctors, compute the most commonly used clinical calculations:

Pharmacokinetics - New Start

Pharmacokinetics - Adjust with Levels

Ideal Body Weight

Creatnine Clearance

Hello

noreply@blogger.com (Rob) — Sat, 20 Jun 2009 06:17:00 +0000

Welcome to the Apple Core Labs weblog. If you'd like to know what we're up to please keep an eye on this site, or our RSS feed.