200

■Bio-mathematics, Statistics and Nano-Technologies: Mosquito Control Strategies

For children under the age of 2 years, the CYP1A2 enzyme follows following equation:

CY P1A2 = 0.24+

1.47Age^1.73

0.36^1.73 +Age^1.73

(10.14)

where children above 2 years, they follow:

CY P1A2 = 0.83+0.79e^{−0.06(Age−1.8)}

(10.15)

For CYP3A4 and CYP3A5, the enzyme maturation changes their maturation rate around

2.3 years, so for children under the age of 2.3 years it is as follows:

CY P3A4 = CY P3A5 = 0.11+

0.95Age^1.91

0.64^1.91 +Age^1.91

(10.16)

where children above 2.3 years, they follow:

CY P3A4 = CY P3A5 = 1.1−0.123e^{−0.05(Age−2.2)}

(10.17)

So, the total degree of enzyme maturation (MFA) in children (under the age of 25) can be

expressed using following equation, where adults, 25 years or older, have MFA = 1:

MFA = (0.21CY P1A2)

+

(0.23CY P2C9)+(0.29CY P2C19)+

+

(0.19CY P3A4)+(0.08CY P3A5)

(10.18)

The body fat proportions in children, plasma proteins, organ sizes etc. are not as they will

be when they grow up. Therefore, children cannot be regarded as small adults and caution

must be taken when dosing are decided and when administrating drugs to this popula-

tion. Different methods have been suggested to extrapolate dosage from adults (Dadult) to

children (Dchild) such as [36]:

Table 10.2: Different dosing rules.

Young’s dosing rule:

Dchild =

Age (y)

Age (y)+12^Dadult

Salomon (Fried) dosing rule:

Dchild = ^{Age (mo)}

150

Dadult

Webster dosing rule:

Dchild = ^{Age (y)+1}

Age (y)+7^Dadult

Clark dosing rule:

Dchild = ^{Weight (lbs)}

150

Dadult

Area dosing rule:

Dchild = ^{BSA (m2)}

1.73

Dadult

A different method has also been proposed based following equation [37]:

Dchild = 1.5

Wchild

70

 ³

4 Dadult

(10.19)