Devices · Pens & autoinjectors

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Devices › Pens & autoinjectors dead volume missed dose storage

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t.vasquezTL4 Moderator29 Oct 2025#1

Community wiki post. Any member at trust level 3 or above can edit this post; every edit is recorded. Last edited by hana.sato on 4 Mar 2026.

27 Jan 2026 — t.vasquez: Replaced an unsourced figure with the published one and cited it.
18 Mar 2026 — mira.patel: Removed a claim that the cited source did not support.
4 Mar 2026 — hana.sato: Clarified the distinction that was causing repeat questions below.

Editors: t.vasquez, mira.patel, hana.sato

Staff post. Actions described here are recorded in the public moderation log and may be challenged in Meta.

Pen mechanics, dose counters, priming, and what happens when a pen is used off its label.

This post is a community wiki: any member at trust level 3 or above can edit it, and every edit is recorded with its author and a note. If the scope described here has drifted from what actually gets posted, edit it rather than starting a topic about it.

What belongs here

Questions specific to pens & autoinjectors, with the units and the context stated.
Reports and datasets, with the collection method stated.
Disagreement about the substance, conducted in public.

What belongs elsewhere

Anything urgent belongs in Safety, immediately, and not here.
Anything about how this site works belongs in Meta.
Requests for a maintained page belong in Wiki requests.

Before posting, it is worth checking the documentation commons and this category's tag pages. A great deal of what gets asked here has a maintained answer with a review date on it, which is more reliable than a two-year-old reply.

0 likes 9mo

hana.satoTL4 Moderator7 Dec 2025#2

Staff post. Actions described here are recorded in the public moderation log and may be challenged in Meta.

Moderation notes for this category, so that nothing about how it is run is a surprise.

Topics get moved into and out of here regularly. A move is not a judgement — the category tree is not obvious from outside and putting a question in the wrong place is expected. When I move something I say so in the topic and the action appears in the public log with the guideline cited.

The two guidelines that come up most often in this category are R2, on supplying a source when asked, and R7, on category placement. Neither is used punitively.

18 likes 8mo

j.asanteTL23 Jan 2026#3

As a member rather than staff: the most useful thing I did when I started reading this category was to work through the tag pages rather than the topic list. The topic list shows you what is recent. The tags show you what is settled.

4 likes 7mo

system_suitabilityTL3Analytical chemist27 Jan 2026#4

Suggestion for the wiki post above: it would be worth linking the two or three most-referenced topics in this category directly, since new members reliably ask for exactly those. Happy to make the edit myself if nobody objects, with a revision note.

0 likes 6mo

i.wojcikTL219 Feb 2026 · edited#5

hana.sato, post #2: Moderation notes for this category, so that nothing about how it is run is a surprise. Topics get moved into and out of here regularly. A move is not a judgement — the category tree is not obvious from outside and putting a question in the wrong place is expected. When I move something I say so in the topic and the action appears in the… Go to post

Pen confusion between compounds: if you are using multiple pens or alternating pens, confirming you have the correct pen before injection prevents administration errors. Check the label every time.

0 likes in reply to #2 5mo

b.jankowiakTL3Regular12 Mar 2026#6

The arithmetic in post #5 is right; the assumption feeding it is the part to check.

Some pens indicate remaining doses and some do not, and reading the residual volume by eye through a window is unreliable at the end of a cartridge.

25 likes 5mo

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