Question

A physician orders codeine gr iss po stat and gr 1/4 q3h prn pain. The available medication is codeine phosphate 15 and 30 mg tablets.

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Which medication strength should be used for the stat dose?

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How many tablets should be administered to the patient as a stat dose?

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What medication strength should be used for the prn dose?

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How many of these tablets should be administered to the patient per prn dose?

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If codeine gr 3/4 is ordered prn, which medication strength would be most appropriate for the administration of the dose?

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How many tablets of the chosen strength would be given for a gr 3/4 prn dose?

Answer 1

Given

Order : Codeine

Dose :1grain (stat) 1/4 grain(prn)

Route :per oral

Frequency :at once and every three hourly

Available :15mg and 30mg tablet

• The ordered stat dose is 1grain
  • As 1grain=65mg
  • The 30mg medication strength has to be used for stat dose
• Dose :1grain(65mg)
  • Available :30mg/tablet
  • So 2.1 or2tablet has to be given in stat dose (30/2)
• First one dose has to be calculated
  • As 1gr=65mg
  • Then 1/4gr=?mg
  • Cross multiply and divide
  • 65/4=16.25mg
  • So prn dose is 16.25mg
  • The medication strength which can used is 15mg
• The number of tablet to be administered is one 15mg tablet
• Convert 3/4gr to mg .As 1part=16.25 ,then 3parts=16.25*3=48.75mg
  • The medication strength which will be most appropriate is 30mg as well as 15mg
• To get the 3/4prn dose either one 30mg and 15mg tablet each can be given or one full 30mg and half 30mg tablet can be given to get the dose .