Concentration

concentrations

concentrations
Is weight over volume (w\v) relationship, it mean certain weight dissolved in certain volume of solvent
The amount of active ingredient in drug is referred to its strength
Amoxicillin cap.500mg(mean active ingredient 500mg ,strength of this drug)

For liquid drugs ,both oral and injectable Concentration is important factor in dosing.

It refers to the amount of active drug(dose in mg) in a given volume vehicle usually a liquid but could be paste. e.g Suspension is 100mg\ml
e,.g ampoule contain 50mg\2ml

concentrations

1%--------------1gm in 100ml
1:100,000--------------1gm in 100,oooml
1:80,000----------------1gm in 80,000ml
2%=2gm of lidocaine in 100ml of solvent

Dose calculation

Dose: is the measured portion of medicine to be taken at one time.


Factors influencing dosage
1- age: children and elderly
2-sex:pregnancy and fetus
3- condition of the patient: resistance ,kidney and liver disease
4-enviromental factors
5-method of administration
6- genetic factor
7-body weight
8- severity of disease

Dose calculation in children

1-Youngs rule:
a Child dose= age of child(year)x average adult dose
age of child(year)+12
CHILD FROM 1-12 years

Dose calculation in children

2- Clarks rule:
Child dose= weight of child(pound)x adult dose
150 pound


Dose calculation in children
3-For infant less than 2 year old use
FRIEDS RULE
child dose= age in months x adult dose
150 pound