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Practice · Interactions · continued

Warfarin and altered intake: the monitoring argument — the long version posts 91–120

This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.

BP
bench_peakTL3Regular16 Jan 2026#91

Coming back to post #89, because the follow-up matters more than the original answer.

Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.

The correction was fair and I had been repeating something I had not checked carefully enough.

32 likes 6mo
TB
t.batistaTL2 Moderator18 Jan 2026#92

Supplements and herbs: many have no established interaction. Some do. If you are taking something unusual, checking a reference (like a pharmacist) is more useful than guessing from forum discussion.

17 likes 6mo
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IsaksenTL319 Jan 2026#93
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s.vogelTL2 Moderator21 Jan 2026 · edited#94

post #93 answers the question as asked. The question underneath it is different.

Oral medications versus time: if you take an oral medication 30 minutes before semaglutide (which slows gastric emptying), the delayed stomach emptying affects when and where the oral medication is absorbed. Separating by a larger interval (1 to 2 hours) usually resolves this.

1 like 6mo
CD
cohort_driftTL3Regular22 Jan 2026#95

I read post #93 twice before replying, because I had assumed the opposite.

Sulfonylureas and meglitinides: these agents stimulate insulin release and carry hypoglycemia risk. Combining them with semaglutide or tirzepatide requires dose adjustment of the secretagogue and close monitoring. The combination is not contraindicated but requires active management.

24 likes 6mo
SO
s.okonkwoTL2 Moderator24 Jan 2026#96

This follows post #93 rather than contradicting it.

Food interactions: most interactions are absorption interactions. Some medications absorb better with food, others better on an empty stomach. With an incretin agonist that already slows gastric emptying, food effects interact with the drug effect as well.

11 likes 6mo
ID
isotonic_driftTL1Member25 Jan 2026#97
e.mwangi, post #18: post #17 is right about the mechanism and I think understates the practical bit. Thyroid medications: semaglutide is associated with a slowing of gastric emptying, which might affect thyroid medication absorption if they are taken very close together. Separating them by a few hours is the conservative approach. Go to post

Metformin: commonly co-administered and relevant to gastrointestinal tolerability. Gastrointestinal side effects can overlap and additive. Taking them separately or adjusting one if tolerability is poor are reasonable approaches.

3 likes in reply to #18 6mo
MN
m.ndiayeTL2 Moderator26 Jan 2026#98

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.

0 likes 6mo
NR
n.rowntreeTL3Regular28 Jan 2026#99

Supplements and herbs: many have no established interaction. Some do. If you are taking something unusual, checking a reference (like a pharmacist) is more useful than guessing from forum discussion.

0 likes 6mo
PF
p.fontaineTL2 Moderator29 Jan 2026#100
l.solberg, post #72: Anticoagulants: no direct interaction with the compounds in this class. Weight loss and body composition changes might affect the clearance or effect of warfarin if you are on it; monitoring INR more frequently during weight loss is reasonable. Go to post

Alcohol: no absolute contraindication but it raises gastrointestinal irritation risk and this drug class already does that. The conservative position during titration is to limit it.

31 likes in reply to #72 6mo
PI
p.iyer_pharmdTL3Pharmacist31 Jan 2026#101
n.duarte, post #38: 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. Go to post

Thyroid medications: semaglutide is associated with a slowing of gastric emptying, which might affect thyroid medication absorption if they are taken very close together. Separating them by a few hours is the conservative approach.

0 likes in reply to #38 6mo
JA
j.asanteTL2 Moderator1 Feb 2026#102

Vitamins: most vitamins have no significant interaction. Fat-soluble vitamins (A, D, E, K) might be affected by the slowing of fat absorption during weight loss, but that is a nutritional consequence rather than an interaction.

19 likes 6mo
SS
system_suitabilityTL3Analytical chemist2 Feb 2026#103

Coming back to post #101, because the follow-up matters more than the original answer.

Anticoagulants: no direct interaction with the compounds in this class. Weight loss and body composition changes might affect the clearance or effect of warfarin if you are on it; monitoring INR more frequently during weight loss is reasonable.

8 likes 6mo
ZO
z.okonkwoTL2 Moderator4 Feb 2026#104

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.

2 likes 6mo
KO
k.otieno_statsTL35 Feb 2026#105
NI
n.ibarraTL2 Moderator7 Feb 2026#106

post #105 is right about the mechanism and I think understates the practical bit.

Separation timing versus clinically important interaction: a separation timing inconvenience (taking one medication 2 hours before or after another) is not the same as a clinically important interaction. Both can reduce absorption of one or the other, but only true interactions require active management.

13 likes 6mo
TP
tracked_parcelTL2Regular8 Feb 2026#107

Insulin interaction: semaglutide and tirzepatide are not contraindicated with insulin but the combination carries hypoglycemia risk if insulin doses are not adjusted. That is a reason for close monitoring, not for avoiding the combination.

5 likes 6mo
SB
s.balogunTL2 Moderator9 Feb 2026#108

Insulin interaction: semaglutide and tirzepatide are not contraindicated with insulin but the combination carries hypoglycemia risk if insulin doses are not adjusted. That is a reason for close monitoring, not for avoiding the combination.

0 likes 6mo
LT
l.trevinoTL2 Moderator11 Feb 2026#109

On post #105 — agreed on the reasoning, with one qualification.

Separation timing versus clinically important interaction: a separation timing inconvenience (taking one medication 2 hours before or after another) is not the same as a clinically important interaction. Both can reduce absorption of one or the other, but only true interactions require active management.

8 likes 5mo
EO
e.okaforTL2 Moderator12 Feb 2026#110

Anticoagulants: no direct interaction with the compounds in this class. Weight loss and body composition changes might affect the clearance or effect of warfarin if you are on it; monitoring INR more frequently during weight loss is reasonable.

1 like 5mo
HN
h.nwosuTL2 Moderator14 Feb 2026#111
sa.vogel, post #56: Picking up post #53: that is the part I would want checked first. Oral medications versus time: if you take an oral medication 30 minutes before semaglutide (which slows gastric emptying), the delayed stomach emptying affects when and where the oral medication is absorbed. Separating by a larger interval (1 to 2 hours) usually resolves… Go to post

Metformin: commonly co-administered and relevant to gastrointestinal tolerability. Gastrointestinal side effects can overlap and additive. Taking them separately or adjusting one if tolerability is poor are reasonable approaches.

0 likes in reply to #56 5mo
O
OstrowskiTL2Member15 Feb 2026#112

Food interactions: most interactions are absorption interactions. Some medications absorb better with food, others better on an empty stomach. With an incretin agonist that already slows gastric emptying, food effects interact with the drug effect as well.

2 likes 5mo
JC
j.cabreraTL2 Moderator16 Feb 2026#113

post #112 answers the question as asked. The question underneath it is different.

Sulfonylureas and meglitinides: these agents stimulate insulin release and carry hypoglycemia risk. Combining them with semaglutide or tirzepatide requires dose adjustment of the secretagogue and close monitoring. The combination is not contraindicated but requires active management.

9 likes 5mo
TS
taper_shiftTL3Regular18 Feb 2026#114

On post #110 — agreed on the reasoning, with one qualification.

Oral medications versus time: if you take an oral medication 30 minutes before semaglutide (which slows gastric emptying), the delayed stomach emptying affects when and where the oral medication is absorbed. Separating by a larger interval (1 to 2 hours) usually resolves this.

21 likes 5mo
VO
v.okonkwoTL2 Moderator19 Feb 2026#115
e.kuipers, post #46: 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. Go to post

Thyroid medications: semaglutide is associated with a slowing of gastric emptying, which might affect thyroid medication absorption if they are taken very close together. Separating them by a few hours is the conservative approach.

0 likes in reply to #46 5mo
F
FFaulknerTL3Regular20 Feb 2026#116

Vitamins: most vitamins have no significant interaction. Fat-soluble vitamins (A, D, E, K) might be affected by the slowing of fat absorption during weight loss, but that is a nutritional consequence rather than an interaction.

0 likes 5mo
BA
b.adeyemiTL2 Moderator22 Feb 2026 · edited#117

post #116 is right about the mechanism and I think understates the practical bit.

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.

5 likes 5mo
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OFalkenbergTL1Member23 Feb 2026#118

SGLT2 inhibitors: frequently co-administered and relevant to renal and cardiovascular discussion, not to interactions. There is no pharmacokinetic interaction of concern.

15 likes 5mo
HM
h.mensahTL2 Moderator25 Feb 2026#119

Picking up post #116: that is the part I would want checked first.

Supplements and herbs: many have no established interaction. Some do. If you are taking something unusual, checking a reference (like a pharmacist) is more useful than guessing from forum discussion.

13 likes 5mo
LS
l.solbergTL2 Moderator26 Feb 2026#120
Ostrowski, post #112: Food interactions: most interactions are absorption interactions. Some medications absorb better with food, others better on an empty stomach. With an incretin agonist that already slows gastric emptying, food effects interact with the drug effect as well. Go to post

Coming back to post #118, because the follow-up matters more than the original answer.

Alcohol: no absolute contraindication but it raises gastrointestinal irritation risk and this drug class already does that. The conservative position during titration is to limit it.

27 likes in reply to #112 5mo