Microneedle patch for monitoring drug levels

Medgadget: “A collaboration between researchers at the University of British Columbia and Paul Scherrer Institut in Switzerland has developed a microneedle device for drug monitoring. The device is in a form of a patch that’s stuck onto the skin, painlessly pushing microneedles through to sample the interstitial fluid…The proof-of-concept device reported by the team was used to measure the concentration of vancomycin.”

microneedle-optofluidic biosensor

This is something that has been sorely needed for a long time. As a pharmacist, I can confidently state that we spend entirely too much time looking at drug levels that are within normal limits versus evaluating those that are not. It would seem much more efficient, at least in the acute care environment, to ignore “normal” levels and spend our time investigating those that are out of whack.

In the outpatient environment this makes even more sense as a patient safety measure. Imagine never again having a patient urgently admitted to the hospital for a drug level that’s way too high. Think of all the medications that require at least intermittent drug levels: carbamazepine, phenytoin, digoxin, tacrolimus, and so on.

Side note, my mother was taking tacrolimus around the time of her liver transplant. An EHR charting error occurred that resulted in her receiving 10 mg orally twice a day instead of 1 mg orally twice a day; yep, a 10-fold error. True story. Almost killed her. The small-town hospital where she lived didn’t recognize the symptoms and failed to get a drug level when she was admitted for “dehydration”. Several days of pleading with physicians and calls to UCSF resulted in a level being drawn. It was off the charts. She was subsequently transferred to UCSF where she spent the next six weeks in the ICU. The entire ordeal could have been avoided with real-time drug monitoring. Just sayin’.

Crowdsourcing pharmacokinetic data

RxCalcPharmacokinetics is something that every hospital pharmacist is intimately familiar with. It just so happens to be one of the things that physicians routinely ask pharmacist to handle. It’s not that doing pharmacokinetic (PK) calculations is difficult, but crunching the numbers can be time consuming and there are occasional traps that can lead to problems for those not experienced in such things.

I’ve performed literally thousands of PK calculations* during my career. When I first began practicing pharmacy there were lots of drugs that required pharmacokinetic monitoring: lidocaine, procainamide, vancomycin, the aminoglycosides, phenytoin, digoxin, phenobarbital, among others. Over the years many of these drugs have been replaced by newer, better agents or simply fallen out of favor.

Some PK calculations can be harder than others, like phenytoin because of its reliance on Michaelis-Menten parameters, or lidocaine because it required loading doses due to its multi-compartment distribution. But others are brain-dead simple. Vancomycin is like that. A monkey could do a new vancomycin start.

During those years one thing remained constant; to perform PK calculations all you needed was a pencil and a calculator. Things have changed over the years with the increased use of computerized software and mobile devices, but the nuts and bolts of the process remains the same.

With the advent of big data one has to wonder why pharmacists continue to do this. Is it a matter of tradition that keeps us tied to pharmacokinetics? It’s hard to say. I remember looking at population trends when I was working as a critical care pharmacist nearly ten years ago. Another pharmacist, Patrick and I kept a spreadsheet of patient ages, gender, height, weight, renal function, infection site, infectious organism(s), and of course drug levels. We were attempting to use our data to find trends that would help us initiate therapy more accurately. Our project never really panned out. We discovered very little in the year we collected the information. The reason for our failure was lack of data and our inability to rigorously study the information in front of us. That’s no longer the case. Given the opportunity, data scientists could analyze hundreds of thousands of PK starts and adjustments to uncover things that Patrick and I could have only dreamt of a decade ago.

So one has to ask whether or not this is being done today, and if not why?


*conservatively I see it as follows:
10 years as a “clinical pharmacist”
50 weeks per year working (hey, everyone needs a vacation)
average of 6-10 new PK starts per day; twice that number of monitoring
taking the low road: 10 x 50 x 6 = 3000

Saturday morning coffee [June 7 2013]: Fast & Furious 6, Peach Cobbler, PRISM, Pharmacy, MedPod

So much happens each and every week that it’s hard to keep up sometimes. Here are some of the tabs that are open in my browser this morning along with some random thoughts….

The headline for SMC is a bit different today in case you haven’t noticed. I’ve taken the advice of a Twitter colleague, Charles Webster, MD (@EHRworkflow). Charles has recommended a couple of times now that I make my headline more descriptive. I like the idea so I’m giving it a shot. Feedback welcome.

My trip to Minneapolis, MN for the ASHP Summer Meeting has me waxing nostalgic. The coffee cup below was my trophy for winning the first ever ASHP Midyear Meeting Twitter contest. I’m not even sure what year it was, but I believe it was 2009; don’t hold me to that recollection though. At that time ASHP  was unable to use any of the official Twitter logos due to some time of licensing issues. So instead they generated a Wordle from my website and placed it on the mug you see below. My Twitter handle (@JFahrni) and web address (JerryFahrni.com) are displayed on the back near the handle.

ASHP Twitter contest mug
Continue reading Saturday morning coffee [June 7 2013]: Fast & Furious 6, Peach Cobbler, PRISM, Pharmacy, MedPod

RxCalc 1.2 ready for download – want a free copy?

RxCalc 1.2 has been approved by the powers to be at Apple and is now available for download in the iTunes store.  For those of you that don’t know about RxCalc, it is a pharmacokinetics calculator made by Apple Core Labs specifically designed to handle aminoglycoside and vancomycin kinetics, i.e. new starts and adjustments. I’ve been intimately involved with the development of RxCalc, and you can read more about what drove the idea and the development of it here if you’re interested.
Continue reading RxCalc 1.2 ready for download – want a free copy?

Hi-Tech patch for migraine relief

ZelrixZelrix is a transdermal patch containing sumatriptan for the treatment of acute migraine headache developed by NuPathe, a pharmaceutical company specializing in the treatment of neurological and psychiatric disorders. The patch is based on NuPathe’s proprietary SmartRelief™ platform, which according to the manufacturer’s website is “a non-invasive technology that utilizes low-level electrical energy to transport drugs through the skin in a safe and effective manner. The rate and amount of drug delivered is controlled electronically, so that the patient receives consistent therapy each and every time. Iontophoresis is an established drug delivery technology with multiple applications currently being used by physicians.” The SmartRelief™ iontophoresis utilizes pre-programmed, embedded electronics in the patch to provide consistent therapeutic drug levels. This is very interesting technology with many potential applications. Imagine the uses in professional sports where iontophoresis is frequently utilized to administer NSAIDS and corticosteroids for the treatment of inflammation

Why I wanted 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.
Continue reading Why I wanted RxCalc

Pharmacokinetics on the iPhone/iPod Touch

iphone_mainmed2Apple Core Labs Blog: “Apple Core Labs first iPhone/iPod Touch application, RxCalc, is now available on the iPhone App Store.”

RxCalc is an idea that my brother and I have had for quite some time. The idea for a portable pharmacokinetics calculator originated many years ago during my infatuation with the TRGpro and the Palm Operating  System. The timing for the application was never quite right, but the appearance of the iPhone changed all that. The portability, advanced features and popularity of the iPhone make it the ideal platform for developing a portable pharmacokinetics calculator.

RxCalc was designed as a tool for pharmacists to perform aminoglycoside and vancomycin kinetics, including new starts using population parameters and dosage adjustments using levels.

The code and user interface was written and developed by Apple Core Labs (Robert Fahrni), while I was responsible for the math and user experience (i.e. the workflow).

Apple Core Labs would like to recruit some pharmacists to use the application and provide feedback, good or bad. To receive a free promotional code redeemable at the iTunes store stop by the Apple Core Labs Blog and simply follow the instructions.


rxadjust rxnewresults