THERE ARE 3 METHODS TO CALCULATE DOSAGES WHEN DRUG STRENGTH IS NOT AVAILABLE

     BASIC FORMULA(F) METHOD

   D (DESIRED DOSE) = Q(QUANITY)= X                                                                             RATIO AND PROPORTION(R/P) METHOD

   H(AVAILABLE)                                                                                                                DOCTOR ORDERS 0.05MG PO

                                                                                                                                       AVAILABLE: 25MCG TAB

EX) ORDER: BENADRYL 30MG PO TID                                                                                *CONVERT MG TO MCG (1MG=1000MCG)*

AVAILABLE: BENADRYL 12.5MG/5ML                                                                                  1MG          0.05MG

30MG    X   5ML= 12ML                                                                                                  1000MCG  = X MCG  =  50MCG

12.5MG

                                                                                                                                  25MCG  = 50MCG

                                                                                                                                   1TAB         X      = 2 TABS

     DIMENSIONAL ANALYSIS(DA) METHOD

EX) DOCTOR ORDERS 0.05MG PO

AVAILABLE: 25MCG TAB

*START OFF BY REVIEWING WHAT KIND OF DOSAGE FORM YOU ARE GOING TO CALCULATE*

TAB=

TAB= 1 TAB

       25MCG

TAB= 1 TAB     1000MCG   0.05MG     *THIS EQUATION IS TO CONVERT MG TO MCG TO HAVE DOSAGE AVAILABILITY EQUALL*

       25MCG X    1MG    X    1TAB

 

TAB= 1 TAB     1000MCG   0.05MG     *CANCEL UNITS OF MEASURE*

       25MCG X    1MG    X    1TAB

                 

                     DO MATH

TAB= 1 TAB     1000          0.05     1X1000X0.05      50

       25       X   1        X    1TAB=     25X1X1     =   25 = 2 TAB

                                HOW TO CALCULATE DAY SUPPLY

INSULIN: 1ML= 100 UNITS                              EAR/EYE: 20 DROPS= 1ML

EX) HUMULIN N U-100                                   EX) SIG: 5 DROPS AD QIDX 7D

     SIG: 35U SQ DAILY                                        QUANITY= 10ML

      QUANITY= 10ML(1000U)                          10ML(STOCK BOTTLE)X20(20D/ML)

 1000/35= 28 DAYS (10ML X 100U)                    =200/ 20DROPS(SIG)=10 DAYS

 

INHALERS: VARY ON ACTUATIONS NUMBERS

EX) ATROVENT (HAS 200 ACTUATIONS)

SIG: INHALE 2X Q12H PO

200/4(SIG)= 50 DAYS

 

LIQUID: VARIES

EX) SIG: 1TSP QID PRN FOR COUGH & COLD

QUANITY=4OZ(120ML)

5X4=20(SIG)--------120/20= 6 DAYS

*TO FIND OUT WHAT OZ BOTTLE TO USE JUST DIVIDE THE QUANITY TO 30*

 

OINTMENT/CREAM: VARIES

EX) SIG: NYSTATIN SKIN OINTMENT(100,000U PER GRAM)

           APPLY TO DIAPER AREA QID

*DAY SUPPLY VARIES DEPENDING HOW MANY TIMES THEY WILL APPLY ON SKIN AND BY LOOKING HOW BIG IS THE TUBE OF OINTMENT*

*BASICALLY THE DAY SUPPLY WOULD BE A QUESS SO THE NYSTATIN OINTMENT WILL LAST 30 DAYS ACCORDING TO THE INFO PROVIDED*

*MOST OINTMENTS AND CREAMS USUALLY LAST 30 DAYS*