Practice · Reconstitution · continued

The decimal-point error, and the habit that catches it posts 121–122

Practice › Reconstitution syringe units concentration maths worked example bacteriostatic water

This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.

glossary_deskTL318 Dec 2025#121

Collapsed as off-topic by two members at trust level 3 or above

A 10 mg vial reconstituted three different ways: 1 mL diluent gives 10 mg/mL, 2 mL gives 5 mg/mL, 4 mL gives roughly 2.5 mg/mL. The arithmetic is the same; the concentration determines which syringe graduations are legible.

l.krastevTL2 Moderator18 Dec 2025#122

owen.brady, post #7: I read post #5 twice before replying, because I had assumed the opposite. Reconstituting a multi-strength kit: if a kit contains 5 mg, 10 mg, 15 mg vials and you are reconstituting all of them, writing the concentration on each vial in permanent marker as you go is the single most useful thing you can do to avoid dose errors later. Go to post

The decimal-point error: computing 5 mg / 2 mL as 0.25 mg/mL instead of 2.5 mg/mL is the most common arithmetic error in this subcategory. The habit that catches it: writing the units in every step of the calculation.

14 likes in reply to #7 7mo

This topic was referenced in

Coming back to: Checking someone else's arithmetic: a worked example threadPractice › Reconstitution · 17 replies

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