# Phamacy dosage question

by Connie
(Oregon)

Amoxicillin suspension 300 mg PO tid is ordered. The amoxicillin suspension that is available is labeled 400 mg / 2 ml. How much amoxicillin is required at each dosing interval?

### Comments for Phamacy dosage question

 Proportion by: Anonymous 400mg - - - - 300mg-------- = --------- 2ml - - - - - X2*300=600Then 600/400=1.5ml

 explain please by: Anonymous I Don't understand... Cross multiplication...?

 explination by: Anonymous you have 400mg/2mL and the patient needs 300mg. To find this answer the easiest way for me is to do the following:Divide 2 by 400 which is 0.005. Then multiply that by 300mg. This will give you your answer which is 1.5 mL.

 set the problem by: Anonymous how do you know how to set the equation or problem

 lynn by: Anonymous how do you know when to cross multiply

 formula by: Anonymous dose you want x mL \ what you have

 Learning metric system by: Tina How can I remember the metric chart and appothecary chart?

 Alternative method by: Anonymous I did it this way:Divide 400mg by 2ml= 200mgThere is 200mg of amoxycillin per 1ml.The patient requires 300mg.0.5ml-100mg1ml- 200mgSo 1.5ml- 300mg

 ml needed by: Anonymous Need/Have x ml amt = 300mg/400mg x 2ml = 1.5 ml

 T.I.D. by: Anonymous Doesn't that mean 3 times a day? (Not B.I.D.)

 Math question by: Anonymous You Have 400mg/2ml You need 300mg/xml400/2=300/xml (cross multiply)300mgx2ml and 400mgxml 600mg/ml over 40mg/ml now divide 600mg by 40= 15mg/ml

 Another view by: Anonymous Instead of setting up proportion, try using dimensional analysis. Always write the units.300 mg X (2 mL/400 mg) = 1.5 mLYou simply set up the given quantity and concentration so that the desired units end up in numerator (in this case, mL) after cancelling the mg in numerator and denominator.

 Pharmacy not phamacy by: Vivi Did anyone else notice pharmacy is misspelled ? lol

 Equation by: Anonymous This can be solved with this equation:D- x VHD- drug ordered H- Drug on HandV - Volume300--- x 2400This equals 1.5 mL

 order over sock by: Anonymous Order over stock times ml300mg (what is ordered)-----400mg (what is in stock)=0.750.75x2ml(which is from 400mg/2ml)=1.5ml per dose

 4.5ml per day by: Anonymous 400mg (x)= 300mg (2ml) x= 600mg/ml Divided by 400mg x= 1.5ml tid =4.5ml per day

 Calculating depo testerone day supply. by: Anonymous Can you help me to understand dosage calculation please

 idk by: Anonymous I don't think the answer is correct - pt. It requires 900(300 tid)tid means three times daily?