FR2530360A1 - RULE FOR PRESCRIPTION OF MEDICINES, ESPECIALLY AMINOSIDES - Google Patents

Abstract

RULE FOR THE PRESCRIPTION OF AMINOSIDES SUCH AS GENTAMYCIN INCLUDING A MAIN ELEMENT 1 WITH DOSE SCALES AND HALF-LIFE CAG, A RULE 2 WITH A DIFFERENTIAL SCALE OF PEAK AND RESIDUAL VALUE B, A MOBILE CURSOR 3 AND A MARKER 6 FOR THE POSITIONING OF RULER 2 FOR READING THE HALF-LIFE SCALES AC G.

Description

Rule for prescribing drugs, including

ment of aminoglycosides.

  The present invention relates to a rule for the prescription of medicinal substances and more particularly

  mainly of diffusion drugs according to a mono- model

  compartmental such as for example the aminoglycosides whose

leader is gentamycin.

  Prescribing antibiotic drugs, com-

  me for example aminoglycosides, must strive to satis-

  make two contradictory conditions, namely on the one hand

  obtaining a peak plasma concentration sufficient

  ment important to ensure the desired bactericidal effect, and on the other hand the need to take into account the undesirable effects such as, for example / the case of aminoglycosides,

  nephrotoxicity or ototoxicity.

  It therefore became common in hospital practice

  heel, to perform assays by blood sample on the one hand at the approximate time of obtaining the peak plasma concentration, for example 60 minutes after administration, and on the other hand, to obtain

  of the residual concentration shortly before the administration

  consecutive administration, administrations generally following each other

  for this kind of antibiotic every eight or twelve hours.

  The practitioner's reaction, when he observes or fears an undesirable side effect, is to reduce the doses successively administered, which then risks leading to insufficient peak values, and therefore to

ineffective treatment.

  This is why the present invention proposes

  to remedy these drawbacks and to provide the practi-

  cien a simple and practical device which allows him quickly to adjust his prescriptions according to the concentrations observed during the samples to optimize his treatment according in particular to the

  renal elimination capacity of the drug.

  Another object of the invention is to provide such a device which is in the form of a simple handling rule and allowing visual control.

  overall likely to virtually eliminate errors.

  Yet another objective of the invention is to provide such a device which is compact and

cheap.

  The subject of the invention is a rule for the prescription of medicinal substances and in particular of aminoglycosides, characterized in that it comprises a main element, a strip capable of sliding longitudinally relative to this main element designed to guide the strip, and a slider carrying an index movable longitudinally both with respect to the main element and with respect to the slide, the main element comprising on the one hand a scale of unit doses graduated in a logarithmic manner, on the other hand-notably a plurality of scales functional parallels, / hyperbolic, graduated in hours, each scale corresponding to a particular frequency of administration, while the slide includes a logarithmic scale graduated in differences between peak and residual concentration and can also be used for displaying peaks

and residual values.

3 2530360

  Preferably, the scales graduated in hours correspond to the administration frequencies of 6 hours, 8 hours, 12 hours, 13 hours and 24 hours, therefore

  usual prescription frequencies.

  It is thus possible thanks to the invention, knowing the dose administered, the value of the peak and the value of the residual concentration, which provides

  a determined differential, read the dose to be administered

  trer to obtain a differential and therefore determine a peak value determined from the next administration which will occur at the time when this value

residual is obtained.

  Furthermore, knowing 'the peak obtained in this way

  that the residual obtained, we can, by moving the cur-

  sor, read the half-life value on the corresponding frequency scale and, by moving the cursor to

  the same value on another frequency scale, deter-

  undermine what would be the residual concentrations if the administration was carried out at this new frequency

  for the same peak or another supposed peak obtained.

  In addition, reading the half-life gives a

  extremely useful indication of kidney function

  the elimination of the drug and possible toxi-

renal city of the drug.

  Other advantages and characteristics of the

  vention will appear on reading the following description

  Vante made by way of non-limiting example and referring to the accompanying drawing in which: Figure 1 shows an elevational view of a device according to the invention with the strip in position

completely back.

  FIG. 2 represents a profile view of this device,

  The device shown comprises a main element

  cipal 1 consisting of a rectangular plate, of

  preferably plastic and one of the faces.

  includes the scales which will be described later.

  In this face, a groove with a dovetail section is practiced inside which can slide

253036 O

  a strip of corresponding shape 2 A cursor 3 surrounding the cross section of the element 1 has

  on its upper side a transparent plastic sheet

  annuity 4 provided with a transverse index 5.

  The cursor and the slider can be independent

  d slideed along the transverse element 1.

  Towards the outer edge of the groove receiving the strip 2, the main element 1 has a graduation

  logarithmic ranged from 3 to 600.

  The ruler has on the adjacent edge a logarithmic graduation b identical but

graduated from 0.3 to 60.

  On its widest surface, that is to say on the other side of the strip 2, the upper face of the element 1 has five scales of the type a / x graduated in hours, namely the scales c corresponding at an administration frequency of 6 hours, d of 8 hours,

  e of 12 hours, f of 18 hours and 2 of 24 hours.

  A reference mark of origin 6 is placed according to the scale, the arrangement of the scales c to q to cooperate with / b of the strip and, by means of the cursor 5,

with scales c to g.

  The operation is as follows: A given patient receives intramuscularly 60 mg of gentamycin three times a day or every eight hours The dosages show a peak of 5.8 Lg / ml and a residual concentration (8 hours after the injection)

  of 2.8 gg / ml The differential is therefore 5.8 2.8 = 3 Rg / ml.

  However, taking into account the treatment, it is desired to obtain 1.2 a peak of 7.2 gg / ml with a residual concentration /

  or a differential of 6 gg / ml.

  The rule according to the invention makes it possible to read the dose administered to obtain this result. For this, we bring

  the graduation 3 of the scale b, i.e. the difference

  tielle, opposite the corresponding dose, i.e. the graduation 60 on the scale a We then refer to the desired differential which is 6 on the scale b and we read, opposite this graduation, the value 125 on unit

  scale a, this value constituting the dose / to be administered.

  It is also interesting to know what the half-life of the drug is and, to this end

  brings the value of the peak observed, that is 5.8, down

  sliding the strip 2 so as to bring the gradua-

  5.8 scale b in front of mark 6 The slider then remains stationary in this position, bring the cursor to the value 2.8 of scale b and then read the value 6.7 in front of l 'index 5 approximately on the d scale The half-life duration is therefore 6.7 hours This value provides valuable information on the renal characteristics of the subject and on the

renal toxicity of the drug.

  We then bring the graduation 7.2 corresponding to the * peak sought, from the scale b of the scale in front of the mark 6 while keeping the cursor in place on the graduation 6.7 of the scale d.

  that index 5 displays a residual value on scale b.

  of 3.5 gg / ml In other words, in 8 hours, the elimination is insufficient to approach the desired residual value, namely 1.2 The strip remains stationary, the cursor is then moved so as to place the 'index in

  correspondence of the value 6.7 on the 12-hour scale e.

  In this case, a residual value slightly less than 2 is obtained opposite the index 5 of the slider on the scale b of the slide If the practitioner admits such a value

  residual of 2, he will administer his dose every 12 hours.

  If, however, he wishes to approach the desired residual value 1.2, he can again move the cursor this time to display 6.7 on the 18 hour f scale and will then be able to observe that the residual concentration will be 1 , 25, i.e. very close to the

value he sought to obtain.

  The practitioner will therefore ultimately prescribe a dose

125 mg every 18 hours.

  Of course, it is possible thanks to this provision

  sitive, by different extrapolations, to immediately reach the desired doses and the frequency of administration

desirable for these doses.

  Although the invention has been described in connection with a particular embodiment, it is understood that it is in no way limited thereto and that one can

  make various changes to it without going too far

  hinder neither its setting nor its spirit.

Claims (8)

  1 Rule for the prescription of medicinal substances and in particular of aminoglycosides, characterized in that it comprises a main element (1), a strip (2) capable of sliding longitudinally relative to this main element (1) designed to guide the strip (2), and a cursor (3) carrying an index (5) movable longitudinally both relative to the element   main (1) that compared to the strip (2), the element   main ment (1) comprising on the one hand a unit dose scale (a) graduated logarithmically, on the other hand a plurality of functional scales (cd,   e, f, g) parallels graduated in hours, each scale corresponds   laying at a particular frequency of administration, while the slide (2) has a logarithmic scale   (b) graduated in differences between peak and resistance concentration   dual and likely to be used-also for   display of peaks and residual values.   2 Rule according to claim 1, characterized in that the scales graduated in hours are capable of providing the half-life of product for administration frequencies of 6 hours, 8 hours, 12 hours, 18 hours and 24 hours.   3 Rule according to any one of claims   1 and 2, characterized in that it comprises, on the main element (1), a mark (6) associated with said scales (c, d, e, f, g), said mark (6) cooperating with the graduation (b) of the strip, the movable index (5) ensuring the connection between said graduation (b) of the strip and said scales (c, d, e, f, g) when the strip (2) is positioned relative to the reference (6).   4 Rule according to any one of claims   1 to 3, characterized in that the scale of the main element   cipal (a) is graduated from 3 to 600 and the scale corresponds to   weight of the slide (b) is graduated from 0.3 to 60.   Rule according to any one of the claims   1 to 4, characterized in that the strip (2) slides in   a dovetail section guide of the main element pal (1).   6 Rule according to any of the claims   1 to 5, characterized in that the scales function-   nelles (c, d, e, f, g) are of the hyperbolic type.