Dose Calculations for the Maintenance Vial < Extractopedia

## Dose Calculations for the Maintenance Vial

Theformulabelowoffersasimpliﬁedmethodforcalculatingthevolumeofan extract to add based on the target dose selected. Importantly, thiscalculationcanbeusedforanypotencyunit(AU, BAU, PNU, w/v, or µg).

V = 10T/E

V: Volume to be drawn up from the manufacturer’s bulk concentrate and added to the patient’s vial

T: Target maintenance dose in 0.5cc injection (e.g., 2000BAU, 1000PNU, 7.5µg Der p 1)

E: Bulkextractconcentration(e.g.,100,000BAUTimothyGrass)

The following assumptions are made, and must be met to use this formula:

1. (1) The volume of the patient’s maintenance vial to be mixed = 5mL
1. (2) The maximum injection volume for the maintenance dose = 0.5cc

This formula is derived from the basic chemical formula for determining volume and concentration:

(V1 x C1 = V2 x C2).

V1 = Target Volume

C1 = Target Concentration V2 = Volume Needed

C2 = Concentration Needed

Forvialsthatfalloutsidetheassumptionsofusinga5mL maintenance vial with a 0.5 cc injection volume, it is best to use the basic chemical formula outlined above.

Examples:

Timothy Grass (Phleum pratense):

Target concentration (T) = 2000 BAU

Extract Concentration (E) = 100,000 BAU

Volume needed(V)=(10*2000)/(100,000)V=20,000/100,000

V = 0.2 mL

House Dust Mites (Dermatophagoides farinae/Dermatophagoides pteronyssinus)

T=1000AU

E = 10,000 AU

V=(10*1000)/10,000V=10,000/10,000

V = 1 mL