Pharmacology · Pharmacokinetics · continued

Peak-to-trough ratio at steady state for a weekly agent posts 61–65

Pharmacology › Pharmacokinetics tirzepatide liraglutide worked example missed dose Solved

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.

n.nybergTL24 Jun 2026#61

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

Fasting requirement for oral semaglutide: food and large fluid volumes reduce absorption. The fasting window (30 minutes before and 30 minutes after) is designed to maximise absorption. Violating it measurably reduces exposure.

m.lehtinenTL2 Moderator4 Jun 2026#62

Renal clearance: these compounds are cleared partly via the kidney. In severe renal impairment, clearance is slowed and accumulation risk is higher. Dose adjustments might be needed.

18 likes 2mo

c.cardosoTL2 Moderator4 Jun 2026 · edited#63

Picking up post #60: that is the part I would want checked first.

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.

0 likes 2mo

c.grimaldiTL2 Moderator4 Jun 2026#64

a.lindqvist, post #13: Accumulation at steady state: with a week-long half-life, steady-state concentration is reached around 4 to 5 half-lives (about 4 to 5 weeks). Before that, concentration is rising with each dose. The clinical implication: escalating before 4 weeks means escalating before steady state. Go to post

SNAC (the oral bioavailability enhancer): sodium N-(8-[2-hydroxybenzoyl]amino) caprylate transiently raises gastric pH and promotes absorption. Without it, oral bioavailability is too low for clinical use. With it, bioavailability is still variable between people.

0 likes in reply to #13 2mo

dr_okonkwoTL4 Moderator4 Jun 2026#65

revision_history, post #27: Picking up post #24: that is the part I would want checked first. Hepatic metabolism: the degree to which each compound is hepatically metabolised versus renally cleared is known but varies. Severe liver disease changes clearance. Go to post

12 likes in reply to #27 2mo

Suggested topics

Topic	Participants	Replies	Views	Activity
Time to steady state after a dose increase Pharmacology › Pharmacokinetics tirzepatide liraglutide worked example missed dose On the subject in the title: Time to steady state after a dose increase Working notes rather than a conclusion. A documentation question rather than an analytical one. I have a certificate in front of me that…	+151	163	9.7k	21mo
Half-life, steady state, and accumulation worked through — a second dataset Pharmacology › Pharmacokinetics semaglutide worked example liraglutide Half-life, steady state, and accumulation worked through — a second dataset — setting out what I have, and where I think it stops being reliable. Working through the identity arithmetic and I would like it…	+110	126	14k	4mo
Peak-to-trough ratio at steady state for a weekly agent — the long version Pharmacology › Pharmacokinetics semaglutide missed dose tirzepatide worked example Under review Peak-to-trough ratio at steady state for a weekly agent — the long version Writing it up because I had to work it out twice and would rather nobody else did. I would like to understand what this number means…	+57	61	708	1d
Washout: how long is long enough, and for what purpose Pharmacology › Pharmacokinetics semaglutide missed dose worked example Closed Washout: how long is long enough, and for what purpose — setting out what I have, and where I think it stops being reliable. A documentation question rather than an analytical one. I have a certificate in…	+63	70	13k	10mo
Coming back to: Half-life, steady state, and accumulation worked through Pharmacology › Pharmacokinetics tirzepatide liraglutide worked example semaglutide On the subject in the title: Half-life, steady state, and accumulation worked through Working notes rather than a conclusion. Working through the identity arithmetic and I would like it checked. semaglutide…	+14	18	15k	3mo

Related topics — sharing the tags tirzepatide, liraglutide, worked example

Topic	Participants	Replies	Views	Activity
Second pass at: Semaglutide and alcohol: what is actually documented Compounds › Semaglutide semaglutide type 2 diabetes effect size randomised trial Closed Second pass at: Semaglutide and alcohol: what is actually documented Writing it up because I had to work it out twice and would rather nobody else did. I have seen STEP 1 ( N Engl J Med , 2021) cited in…	+15	19	4.4k	13mo
Follow-up: A partial dose because the pen emptied mid-injection Practice › Administration injection site reaction subcutaneous injection injection site rotation aseptic technique Posting this under the heading it deserves: A partial dose because the pen emptied mid-injection Everything below is what sits behind that. I have read the maintained page on this and I still have a gap, so I…	+10	14	10k	23mo
Injection discomfort: needle gauge, volume, temperature, technique Practice › Administration subcutaneous injection injection site reaction needle gauge & length aseptic technique Injection discomfort: needle gauge, volume, temperature, technique — setting out what I have, and where I think it stops being reliable. Practical question with the units stated, because I have seen how…	+66	71	14k	2mo
Rotating between abdomen, thigh and upper arm: absorption differences — one year on Practice › Administration injection site reaction needle gauge & length aseptic technique injection site rotation Rotating between abdomen, thigh and upper arm: absorption differences — one year on — setting out what I have, and where I think it stops being reliable. I have read the maintained page on this and I still…	+82	102	24k	just now
How to ask a question when you cannot say why you are asking it Start Here › How to Ask beginner friendly site feedback worked example onboarding Solved Asking directly, because I could not find a straight answer: How to ask a question when you cannot say why you are asking it Question in the title. Context below, and I have tried to include the things people…	+49	53	36k	4h