Archived Message board responses
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Does anyone have safety and stability data on the use of high concentrations of morphine (greter than 50mg/ml) in intrthecal pumps?

In Reply to: Concentrated morphine posted by C. Williams on May 28, 2001 at 09:30:51:

It shouldn't be done as it is outside of compendial standards. Depending upon one's reference source (Martindale's or USP) the solubility of morphine sulfate is between 50-60mg/ml at ideal conditions. From experience with epidural preps when morphine sulfate is prepared at concentrations higher than 50mg/ml it precipitates out at cooler (refrigerated) temperatures.

And a clinical anecdote: Many years ago we were referred a patient who supposedly was receiving a subcutaneous infusion of 120mg/ml morphine sulfate (@ 1ml/hour). When I queried the compounding pharmacist about his technique he stated that he used warmed up water for compounding and kept the drug reservoir warm. Well, after admission to the hospital it was no surprise to discover that the patient was adequately stabilized on 1ml/hour of a 30mg/ml MS solution.

Your alternatives should be to consider using hydromorphone or fentanyl along with adjuncts such as bupivacaine or clonidine (additional info is available at my web site).

I know lidocaine is often infused with high concentration K run , but recently a nurse said that she used to add pediatric NaHco3 to the bag to get the same result. Doesnt this defeat the purpose, since Nahco3 pushes K back into cells.??
Also, what dose lidocaine to use. I have used 10 mg per 40 meq bag,but understand you can use 25??

In Reply to: potassium run posted by tom wise on June 13, 2001 at 00:12:36:

In most cases I would recommend slowing the infusion or increasing the amount of fluid and not relying on the use of lidocaine.

If lidocaine is used, here are a couple of references:

1) Drug Intell Clin Pharm 1988 Sep;22(9):676-9
Patient tolerance to intravenous potassium chloride with and without lidocaine.
Pucino F, Danielson BD, Carlson JD, Strommen GL, Walker PR, Beck CL, Thiege DJ, Gill DS.
Department of Pharmacy Practice, College of Pharmacy, North Dakota State University, Fargo.

Abstract
Hypokalemia is a common electrolyte abnormality. Intravenous repletion therapy with potassium chloride (KCl) in concentrations greater than 80-100 mEq/L is not recommended due to patient intolerance. Since this guideline at times may be clinically impractical, this study was designed to examine use of peripheral vein infusions of high concentration KCl therapy. Tolerance to KCl 20 mEq/65 ml iv with and without lidocaine 50 mg was evaluated in 18 hypokalemic subjects in a randomized, placebo-controlled, double-blind study. Subjective and objective assessments of adverse effects were determined throughout the infusion period. Pain was assessed by both verbal descriptor and visual analog scales and correlated significantly following infusion of KCl with or without lidocaine. Multivariant analysis demonstrated differences in pain perception between solutions, with significantly less pain following KCl with lidocaine versus KCl infusions. Transient adverse effects occurred in both groups, but the incidence was not statistically different. Use of concentrated iv KCl infusions may benefit hypokalemic patients with hypervolemia and/or severe potassium deficits. Addition of lidocaine clearly improves patient tolerance to intravenous KCl replacement.

2) Morrill GB, Katz MD.
The use of lidocaine to reduce the pain induced by potassium chloride infusion.
J Intraven Nurs. 1988 Mar-Apr;11(2):105-8.

3) Lim ET, Khoo ST, Tweed WA, Kloo ST.
Efficacy of lignocaine in alleviating potassium chloride infusion pain.
Anaesth Intensive Care. 1992 May;20(2):196-8.
Department of Anaesthesia, National University Hospital, National University of Singapore.

Abstract
A double-blind study was set up to investigate the effect of pretreatment with lignocaine on the incidence of potassium chloride infusion pain. Twenty-eight patients were randomly allocated into two equal groups. Patients in both groups were hypokalaemic and were scheduled for replacement consisting of potassium chloride 20 mmol diluted to 100 ml in dextrose 5% solution administered over two hours. Group A (lignocaine) patients were pretreated with a bolus dose lignocaine 3 ml 1%, Group B (control) received isotonic saline 3 ml. The incidence of potassium chloride infusion pain was significantly reduced in Group A. There was no adverse effect reported. This study demonstrates the efficacy of bolus dose of lignocaine in alleviating injection pain for the duration of a two-hour continuous infusion.

Web site review:
1) "While there is some evidence that use of lidocaine can alleviate infusion discomfort, there are concerns about its use and it is not widely endorsed." --Source--

2) Protocol: "The physician must write an order to specify that 1ml of lidocaine HCl 1% (10 mg/ml) can be added to 10 mEq potassium chloride in volume of 100 ml of dextrose 5% or normal saline 0.9%." ---Source--

Hope this helps..

Is it okay to use calcium chloride IVPB instead of
calcium gluconate IVPB to treat hyperkalemia ?
If it's okay, is it the same dose as calcium
gluconate (i.e. 1 ampule CaCl2 = 1 amp Calcium
gluconate?) ?
Thanks

In Reply to: Calcium chloride for hyperkalemia posted by michiganian on June 24, 2001 at 00:58:56:

Calcium chloride may be used, but remember that calcium chloride has approximately 3 times as much elemental calcium. For this reason some textbooks will recommend calcium gluconate as a more conservative approach. In life-threatening hyperkalemia calcium chloride would obviously be a valid choice.

10 ml (1 gram of calcium gluconate) is equivalent to 3.41 ml (0.34 grams) of calcium chloride. Reference: http://www-users.med.cornell.edu/~spon/picu/calc/cacalc.htm

Dave,
what's the clinical significance of the q-t wave elongation with the use of levaquin? According to a memo recvd at BGH "a known class effect of all the quinolones to cause QT prolongation" initiates a "severity level one drug interaction".
hope things are well with you and all at VA.
Bob

In Reply to: q-t elongation posted by bob devore on July 08, 2001 at 19:09:25:

INTERNATIONAL REGISTRY OF DRUG INDUCED ARRHYTHMIAS---QTdrugs.org is devoted to Education and Research on drug-induced arrhythmias, especially those due to prolongation of the QT interval on the electrocardiogram (ECG).
>>>>>>

Posted by D. McAuley on July 08, 2001 at 22:47:31:

In Reply to: q-t elongation posted by bob devore on July 08, 2001 at 19:09:25:

: Hello Bob! That statement is a little misleading. The individual fluoroquinolones have varying effects on the QT interval with grepafloxacin and sparfloxacin having the greatest effect. Levofloxacin is at the other end of the spectrum (normal doses have little effect on the QT interval--although there may be exceptions). I did a quick literature search to back up this statement:

Mol Pharmacol 2001 Jan;59(1):122-6
Interactions of a series of fluoroquinolone antibacterial drugs with the human cardiac K+ channel HERG.
Kang J, Wang L, Chen XL, Triggle DJ, Rampe D.
Aventis Pharmaceuticals, Inc., Bridgewater, New Jersey 08807-0800, USA.

Administration of certain fluoroquinolone antibacterials has been associated with prolongation of the QT interval on the electrocardiogram and, on rare occasions, ventricular arrhythmia. Blockade of the human cardiac K+ channel HERG often underlies such clinical findings. Therefore, we examined a series of seven fluoroquinolones for their ability to interact with this channel. Using patch-clamp electrophysiology, we found that all of the drugs tested inhibited HERG channel currents, but with widely differing potencies. Sparfloxacin was the most potent compound, displaying an IC50 value of 18 microM, whereas ofloxacin was the least potent compound, with an IC50 value of 1420 microM. Other IC50 values were as follows: grepafloxacin, 50 microM; moxifloxacin, 129 microM; gatifloxacin, 130 microM; levofloxacin, 915 microM; and ciprofloxacin, 966 microM. Block of HERG by sparfloxacin displayed a positive voltage dependence. In contrast to HERG, the KvLQT1/minK K+ channel was not a target for block by the fluoroquinolones. These results provide a mechanism for the QT prolongation observed clinically with administration of sparfloxacin and certain other fluoroquinolones because free plasma levels of these drugs after therapeutic doses approximate those concentrations that inhibit HERG channel current. In the cases of levofloxacin, ciprofloxacin, and ofloxacin, inhibition of HERG occurs at concentrations much greater than those observed clinically. The data indicate that clinically relevant HERG channel inhibition is not a class effect of the fluoroquinolone antibacterials but is highly dependent upon specific substitutions within this series of compounds. HERG channel affinity should be an important criterion for the development of newer fluoroquinolones.

Here is a link to an editorial (BMJ). and here is the full text version: BMJ 2000;320:1158-1159 ( 29 April ) Risk of torsades de pointes with non-cardiac drugs. Prolongation of QT interval

Hope this helps... By the way, are you still working the 7 days on/off schedule?

We have an order for Keppra 3 grams BID, the maximum
dose we can find for 24 hours is 4 grams, do you have
any information on doses higher than 4 grams/24 hours.

In Reply to: Keppra maximum dosing posted by Pam Palmer on July 10, 2001 at 19:36:27:

I agree with the maximum dose of 4 grams. Clinical studies in progress have used an upper limit of 4 grams. A literature search produced similar results. Here is an excerpt from the most recent journal:

Epilepsy Res 2000 Dec;42(2-3):89-95
Efficacy and tolerability of 1000-4000 mg per day of levetiracetam as add-on therapy in patients with refractory epilepsy.

Grant R, Shorvon SD.

Department of Clinical Neurosciences, The University of Edinburgh, Western General Hospitals NHS Trust, Crewe Road, EH4 2XU, Edinburgh, UK.

The aim of this study was to determine the efficacy and tolerability of 1000-4000 mg/day of levetiracetam (LEV, Keppra) as add-on treatment for refractory epilepsy. This was a dose-escalation study of 29 patients with refractory epilepsy. Patients received placebo for 4 weeks (baseline) followed by levetiracetam 1000 and 2000 mg per day each for 2 weeks, and then 3000 and 4000 mg per day each for 4 weeks. Primary efficacy was assessed by seizure frequency (number/week). Tolerability was assessed by adverse events, laboratory parameters, clinical evaluations, and electrocardiogram. All the study periods were completed by 27 of the 29 patients. A substantially lower median seizure frequency was observed at all levetiracetam dosing periods (1000 mg per day, 1.0 seizures per week; 2000 mg per day, 1.5 seizures per week; 3000 mg per day, 1.0 seizures per week; 4000 mg per day, 0.75 seizures per week) compared with the placebo treatment (2.06 seizures per week). In addition, 22-33% of these patients were seizure free during treatment with levetiracetam compared with only 14% with placebo. Levetiracetam was well tolerated. The most common adverse events were somnolence and asthenia; frequency and severity increased with increasing doses of levetiracetam. Levetiracetam in doses from 1000 to 4000 mg per day is effective. Somnolence and asthenia were more frequent with the highest dose, suggesting that 4000 mg per day may be the upper limit in some patients, although individual susceptibility to somnolence was variable.

^^^^^^^^^^^^^^
Also:

Clinical studies registered with the N.I.H.

Is there a comprehensive resource available listing latex content of medications?

In Reply to: Latex posted by Linda on July 12, 2001 at 20:39:49:

Most of what I could find about Latex on the internet involves prevention and management of Latex allergies. There was one reference to a Latex Information Handbook but I was unable to locate it.
Here is an example:
http://www.cdc.gov/niosh/latexalt.html

Who, out there, has a pharmacy computer system that you like & works well. E-mail me with your ideas, opinions. My company is searching for another system. And would appreciate any evaluations and hints from the great "pharmacy knowledge base". Thanks in advance.

Mary Ann

In Reply to: pharmacy computer systems posted by M. Stokes, R.Ph. on July 13, 2001 at 10:27:52:

I guess nobody likes their computer system. ;)
I am familiar with Pharmakon 2000 (don't buy it),
Medics, Meditech, Star, Omega, Pharmtrack, Cerner.
does anybody have any comments??
e mail me at [email protected]
thanks
mary ann
>>>>>>>>>>>>>>>>>>

Posted by Bill on July 25, 2001 at 11:34:49:

In Reply to: Re: pharmacy computer systems posted by m.stokes on July 22, 2001 at 12:24:55:

Check out this site: click here

>>>>>>>>>>>>>>>>>>>>

Posted by Jeff on October 18, 2001 at 16:30:45:

In Reply to: Re: pharmacy computer systems posted by Bill on July 25, 2001 at 11:34:49:

We have had Medics in the past and loved it, but it was not multifacility capable at the time. We then went with HBOC(now McKesson) Star Pharmacy.
Its ok, but the upgrade path is slow. We are converving to McKesson Horizon Meds Manager(formerly Medics) and look forward to going back to a superior product.

Does anyone have any guidelines regarding management of levaquin extravasation?

In Reply to: Levaquin extravasation posted by Jan on July 17, 2001 at 17:25:22:

Here are 2 general references that should help you:
Extravasation. Here is another.

What information is available regarding maximum dosages utilized in weight-based indications for enoxaparin?

In Reply to: Enoxaparin dosing in obese patient population posted by WHM on July 20, 2001 at 12:17:14:

Data submitted to the FDA did not take into account extremes in weight. Further studies are needed to clearly define therapeutic limits. Here is an excerpt from one of the leading journals dealing with anticoagulation:

Monitoring LMWH in Patients With Obesity or Renal Failure

Randomized trials of LMWH either excluded patients with renal failure or failed to specify whether such patients were recruited. When LMWH is administered to patients with renal failure, it is prudent to check anti-Xa levels periodically to avoid accumulation to toxic levels.

Anti-Xa assays in use throughout North America are highly variable: one specimen tested in 46 laboratories yielded mean LMWH anti-Xa activity of 0.7 IU/mL with a SD of 0.1, and a range of 0.8 to 1.0 IU/mL."

Source:

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Posted by Tim Clark on July 23, 2001 at 07:02:03:

There ia a good review artical in Pharmacotherapy on this question.
Tim Clark, PharmD
MCGH
Duplaga BA, et. al. Pharmacotherapy 2001;21(2):218-234