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Follow-up: A site rotation scheme that is easy enough to actually follow

MH
m.haddadTL2Regular29 Aug 2024#1

A site rotation scheme that is easy enough to actually follow Writing it up because I had to work it out twice and would rather nobody else did.

Practical question with the units stated, because I have seen how quickly these go wrong without them.

I have a 2 mg vial of tirzepatide and I am working to a 0.25 mg step. My syringes are U-100 insulin syringes, 0.5 mL barrel.

I can do the arithmetic and I have done it twice, getting the same answer both times, but I would like someone to check the reasoning rather than the number — specifically whether I have thought about the residual volume correctly, and whether the graduation I am landing on is one a person can actually read.

13 likes 23mo
NA
n.achebeTL2 Moderator30 Aug 2024#2

Angle of injection: 90 degrees into pinched tissue ensures subcutaneous placement. It is not always necessary and shallower angles can work, but 90 degrees into a small pinch is the safest technique to learn first.

1 like 23mo
I
IsaksenTL3Regular31 Aug 2024#3

Bleeding at the injection site: normal and usually minimal. A little blood at the needle site after withdrawal is not a reason to assume you lost a significant dose. The needle passed through tissue and there is a small amount of bleeding in the tract.

32 likes 23mo
TI
t.ibarraTL2 Moderator1 Sep 2024#4

Leak-back after withdrawal: a small amount of liquid on the skin after withdrawal is ordinary. Whether you lost a "meaningful" dose depends on concentration and your target dose, but some leak-back is universal and does not need to be treated as an error.

17 likes 23mo
NR
n.rowntreeTL3Regular2 Sep 2024#5

Worth separating two things that the opening post runs together.

Pinch or no pinch: the decision depends on needle length and on your own anatomy. A longer needle (8 mm and up) reaches subcutaneous tissue easily without a pinch. A shorter needle (4-6 mm) is safer with a gentle pinch. The pinch size matters less than people think; the injection angle matters more.

11 likes 23mo
RB
r.bakkenTL2 Moderator2 Sep 2024#6
n.rowntree, post #5: Worth separating two things that the opening post runs together. Pinch or no pinch: the decision depends on needle length and on your own anatomy. A longer needle (8 mm and up) reaches subcutaneous tissue easily without a pinch. A shorter needle (4-6 mm) is safer with a gentle pinch. The pinch size matters less than people think; the… Go to post

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

3 likes in reply to #5 23mo
AP
abstract_peakTL1Member3 Sep 2024#7

Drawing up with one needle and injecting with another: a reasonable practice if you have extra needles. Fresh needle for injection reduces tissue drag and can decrease discomfort. Not necessary, but not harmful either.

0 likes 23mo
BC
b.correiaTL2 Moderator4 Sep 2024#8

This follows post #5 rather than contradicting it.

A genuinely late dose: the labelling generally says that if the next dose is more than a couple of days away, take it as soon as you notice. If the next dose is close, skip it and resume the schedule. The reasoning follows from the long half-life; you are perturbing a slowly moving average.

23 likes 23mo
K
KAnderssonTL3Regular4 Sep 2024#9
t.ibarra, post #4: Leak-back after withdrawal: a small amount of liquid on the skin after withdrawal is ordinary. Whether you lost a "meaningful" dose depends on concentration and your target dose, but some leak-back is universal and does not need to be treated as an error. Go to post

A site rotation scheme that actually works: abdomen, outer thigh, back of arm, outer hip. Rotate through them in order, move a minimum 2 cm between consecutive sites, note the site with each dose. If a local reaction appears you have the history. If you rotate properly you will not get lipohypertrophy from overuse of one area.

16 likes in reply to #4 23mo
EN
e.ndiayeTL2 Moderator5 Sep 2024#10

Injecting into an area that has become firm: lipohypertrophy — thickened fatty tissue from repeated injection in one area — changes local tissue absorption. Avoid injecting into areas that are noticeably firm or lumpy and allow those areas to recover for at least a few months.

6 likes 23mo
L
LJankowiakTL3Regular5 Sep 2024#11

post #10 is right about the mechanism and I think understates the practical bit.

Injection discomfort: comes from needle gauge (finer = less discomfort), volume (smaller = less discomfort), temperature (room temperature or warmed is less uncomfortable than cold), and technique (smooth, purposeful injection is less uncomfortable than hesitant). All four are under your control.

0 likes 23mo
AC
a.cardosoTL2 Moderator6 Sep 2024 · edited#12

Cold solution and stinging: warming the vial in your hands for a minute before injection reduces the stinging sensation substantially. This is the simplest thing to try if injections are uncomfortable.

2 likes 23mo
BR
buffer_reviewTL3Regular7 Sep 2024#13
a.cardoso, post #12: Cold solution and stinging: warming the vial in your hands for a minute before injection reduces the stinging sensation substantially. This is the simplest thing to try if injections are uncomfortable. Go to post

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

12 likes in reply to #12 23mo
SV
sa.vogelTL2 Moderator7 Sep 2024#14

I read post #12 twice before replying, because I had assumed the opposite.

Air bubbles in a subcutaneous injection: the honest risk assessment is low. Tiny air bubbles in subcutaneous tissue do not behave like an air embolism in a blood vessel. A few air bubbles are not a reason to restart the entire injection.

26 likes 23mo
TS
t.steenkampTL2Member8 Sep 2024#15

post #14 answers the question as asked. The question underneath it is different.

Pinch or no pinch: the decision depends on needle length and on your own anatomy. A longer needle (8 mm and up) reaches subcutaneous tissue easily without a pinch. A shorter needle (4-6 mm) is safer with a gentle pinch. The pinch size matters less than people think; the injection angle matters more.

0 likes 23mo
KA
k.adeyemiTL2 Moderator8 Sep 2024#16
e.ndiaye, post #10: Injecting into an area that has become firm: lipohypertrophy — thickened fatty tissue from repeated injection in one area — changes local tissue absorption. Avoid injecting into areas that are noticeably firm or lumpy and allow those areas to recover for at least a few months. Go to post

On post #12 — agreed on the reasoning, with one qualification.

A genuinely late dose: the labelling generally says that if the next dose is more than a couple of days away, take it as soon as you notice. If the next dose is close, skip it and resume the schedule. The reasoning follows from the long half-life; you are perturbing a slowly moving average.

4 likes in reply to #10 23mo
AD
ambient_draftTL3Regular9 Sep 2024#17
sa.vogel, post #14: I read post #12 twice before replying, because I had assumed the opposite. Air bubbles in a subcutaneous injection: the honest risk assessment is low. Tiny air bubbles in subcutaneous tissue do not behave like an air embolism in a blood vessel. A few air bubbles are not a reason to restart the entire injection. Go to post

Bleeding at the injection site: normal and usually minimal. A little blood at the needle site after withdrawal is not a reason to assume you lost a significant dose. The needle passed through tissue and there is a small amount of bleeding in the tract.

18 likes in reply to #14 23mo
MA
mi.amankwahTL2 Moderator9 Sep 2024#18

A site rotation scheme that actually works: abdomen, outer thigh, back of arm, outer hip. Rotate through them in order, move a minimum 2 cm between consecutive sites, note the site with each dose. If a local reaction appears you have the history. If you rotate properly you will not get lipohypertrophy from overuse of one area.

0 likes 23mo
MC
m.coelhoTL2 Moderator10 Sep 2024#19

Leak-back after withdrawal: a small amount of liquid on the skin after withdrawal is ordinary. Whether you lost a "meaningful" dose depends on concentration and your target dose, but some leak-back is universal and does not need to be treated as an error.

27 likes 23mo
BS
b.solbergTL2 Moderator10 Sep 2024#20
LJankowiak, post #11: post #10 is right about the mechanism and I think understates the practical bit. Injection discomfort: comes from needle gauge (finer = less discomfort), volume (smaller = less discomfort), temperature (room temperature or warmed is less uncomfortable than cold), and technique (smooth, purposeful injection is less uncomfortable than… Go to post

Worth separating two things that post #16 runs together.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

0 likes in reply to #11 23mo
JC
j.cabreraTL2 Moderator11 Sep 2024 · edited#21

Injecting into an area that has become firm: lipohypertrophy — thickened fatty tissue from repeated injection in one area — changes local tissue absorption. Avoid injecting into areas that are noticeably firm or lumpy and allow those areas to recover for at least a few months.

16 likes 23mo
F
FFaulknerTL3Regular11 Sep 2024#22

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

6 likes 23mo
HN
h.nwosuTL2 Moderator12 Sep 2024#23
sa.vogel, post #14: I read post #12 twice before replying, because I had assumed the opposite. Air bubbles in a subcutaneous injection: the honest risk assessment is low. Tiny air bubbles in subcutaneous tissue do not behave like an air embolism in a blood vessel. A few air bubbles are not a reason to restart the entire injection. Go to post

Coming back to post #21, because the follow-up matters more than the original answer.

Angle of injection: 90 degrees into pinched tissue ensures subcutaneous placement. It is not always necessary and shallower angles can work, but 90 degrees into a small pinch is the safest technique to learn first.

1 like in reply to #14 23mo
TS
taper_shiftTL3Regular12 Sep 2024#24
e.ndiaye, post #10: Injecting into an area that has become firm: lipohypertrophy — thickened fatty tissue from repeated injection in one area — changes local tissue absorption. Avoid injecting into areas that are noticeably firm or lumpy and allow those areas to recover for at least a few months. Go to post

Picking up post #21: that is the part I would want checked first.

Injection discomfort: comes from needle gauge (finer = less discomfort), volume (smaller = less discomfort), temperature (room temperature or warmed is less uncomfortable than cold), and technique (smooth, purposeful injection is less uncomfortable than hesitant). All four are under your control.

0 likes in reply to #10 23mo
BA
b.adeyemiTL2 Moderator13 Sep 2024#25

Drawing up with one needle and injecting with another: a reasonable practice if you have extra needles. Fresh needle for injection reduces tissue drag and can decrease discomfort. Not necessary, but not harmful either.

22 likes 22mo
I
IMainwaringTL3Regular13 Sep 2024#26

post #25 is right about the mechanism and I think understates the practical bit.

Cold solution and stinging: warming the vial in your hands for a minute before injection reduces the stinging sensation substantially. This is the simplest thing to try if injections are uncomfortable.

10 likes 22mo
VO
v.okonkwoTL2 Moderator13 Sep 2024#27

I read post #25 twice before replying, because I had assumed the opposite.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

3 likes 22mo
O
OFalkenbergTL1Member14 Sep 2024#28
sa.vogel, post #14: I read post #12 twice before replying, because I had assumed the opposite. Air bubbles in a subcutaneous injection: the honest risk assessment is low. Tiny air bubbles in subcutaneous tissue do not behave like an air embolism in a blood vessel. A few air bubbles are not a reason to restart the entire injection. Go to post

Air bubbles in a subcutaneous injection: the honest risk assessment is low. Tiny air bubbles in subcutaneous tissue do not behave like an air embolism in a blood vessel. A few air bubbles are not a reason to restart the entire injection.

0 likes in reply to #14 22mo
MA
m.amankwahTL2 Moderator14 Sep 2024#29

On post #25 — agreed on the reasoning, with one qualification.

Angle of injection: 90 degrees into pinched tissue ensures subcutaneous placement. It is not always necessary and shallower angles can work, but 90 degrees into a small pinch is the safest technique to learn first.

30 likes 22mo
VS
vial_slopeTL3Regular15 Sep 2024 · edited#30

Injection discomfort: comes from needle gauge (finer = less discomfort), volume (smaller = less discomfort), temperature (room temperature or warmed is less uncomfortable than cold), and technique (smooth, purposeful injection is less uncomfortable than hesitant). All four are under your control.

15 likes 22mo