Question

Ceftriaxone 1 needs to be mixed with lidocaine 1% to a final volume of 250mg / mL If the patient is to get 350 mg IM, how many milliliters should be injected?

Answer 1

To administer a 350 mg dose of ceftriaxone mixed with lidocaine at a concentration of 250 mg/mL, the patient requires an injection of 1.4 mL of the solution.

Step-by-step explanation:

To calculate the volume of ceftriaxone-lidocaine solution to be injected intramuscularly (IM) to deliver a dose of 350 mg, one must consider the concentration of the final mixed solution. Given that the final concentration is 250 mg/mL, the volume (V) required to achieve the desired dose (D) of 350 mg can be calculated using the formula:

D = V × C

where:

• D is the dose in mg
• V is the volume in mL
• C is the concentration in mg/mL

Rearranging the formula to solve for volume (V):

V = D / C

Plugging in the values:

V = 350 mg / 250 mg/mL = 1.4 mL

Therefore, to administer a dose of 350 mg with a solution concentration of 250 mg/mL, the patient should be injected with 1.4 mL of the solution.