Every letter we have printed
Page 59 of 77 of this archive, newest first.
On “Delayed emptying explains some of this, and not all of it” — Patient Notes, 18 Aug 2024
The gallbladder section says some of the excess is attributable to weight loss rather than the drug. If the drug causes the weight loss, is that not a distinction without a difference for the person who ends up in theatre?
— D. Lockridge, Tulsa, OK
For the individual, largely yes. For the question of whether one molecule is safer than another, or whether the risk would fall on slower loss, the distinction is the whole question. We should have made clear that it is a mechanistic distinction rather than a consoling one.
On “Four ways a peptide comes apart” — The Supply Chain, 18 Aug 2024
You draw a distinction between retest date and expiry date and then say suppliers use the wrong word. Which word do you think they should use, given that most of them have no study behind either?
— I. Mukherjee, Kolkata
Retest, with a stated interval and a note that no formal stability study supports it. That is an honest description of a chemical supplier’s position and it is standard practice in the wider chemical trade. Printing expiry implies a study exists, which is the specific inference we object to.
On “Four ways a peptide comes apart” — The Supply Chain, 18 Aug 2024
I would add one omission to your list. Nobody states the headspace gas. Nitrogen-backfilled vials and air-sealed vials behave differently for any oxidation-prone sequence, and it is a single word on a certificate.
— M. Halim, Kuala Lumpur
On “Four ways a peptide comes apart” — The Supply Chain, 18 Aug 2024
Parcel 7 reached thirty-eight degrees for nearly four hours and you then tell readers not to worry unduly. I accept the solid-state argument. I would still like to know what the material looked like on analysis, and your article does not say.
— L. Kowalski, Gdańsk
A fair criticism of the reporting. Parcel 7 was submitted for purity determination on arrival and returned a figure within a percentage point of the supplier’s stated value, which is consistent with the solid-state argument and proves very little on its own, since we had no pre-shipment measurement on that vial. The design fault is ours: a shipment study without a paired baseline sample cannot answer the question we most wanted answered, and the next round will.
On “Four ways a peptide comes apart” — The Supply Chain, 18 Aug 2024
On amber glass: it is not merely cheap, it is standard in the wider chemical supply trade for anything with a chromophore. The fact that this market ships peptides in clear glass is a sign of who is doing the filling more than of any decision about photostability.
— B. Osei-Bonsu, Kumasi
On “Electrospray, MALDI, and the choice that shapes every spectrum after it” — Analytics, 16 Aug 2024
You give the glutamine-to-lysine difference as 0.036 daltons and say it needs an orbital trap. In practice you also need the two species to be chromatographically separated or present in a sensible ratio, because at one per cent of the parent intensity the minor peak sits on the shoulder of the isotope envelope regardless of resolving power.
— P. Ekundayo, Akure
Yes, and this is the more useful statement of the problem. Resolving power is necessary and not sufficient; dynamic range and separation matter as much. We have added a sentence to the table note.
On “Electrospray, MALDI, and the choice that shapes every spectrum after it” — Analytics, 16 Aug 2024
A small defence of the linear MALDI instrument. It is fast, it tolerates dirty samples, and for a synthesis chemist checking that a chain has grown by the residue intended it is entirely fit for purpose. The problem is not the instrument. It is printing its output on a release document.
— J. Wenninger, Graz
This is the same objection a reader made about the twelve-minute purity gradient two years ago, and it was right then as well. The criticism is of the use, not the tool.
On “From vial to bench: what is recorded and what is assumed” — The Ledger, 16 Aug 2024
As a buyer I found the section on who chose the vial genuinely clarifying and slightly deflating. I have been treating vendor-published reports as equivalent to my own submissions for two years, and on your account they are not equivalent by an amount that cannot be measured.
— B. Wojciechowski, Kraków
That is the correct reading, and the unmeasurable part is the honest part. We would add only that vendor-published reports are not worthless — a vendor willing to commission testing at all is behaving better than one that will not — they are simply weaker in a specific way.
On “Two-thirds back: the extension nobody expected to be the headline” — Patient Notes, 15 Aug 2024
As a prescriber I would push back on your framing of the maintenance gap. We are not practising without evidence; we are practising on pharmacological inference, which is what clinicians do in every field where the trial has not been run. Calling it unevidenced makes reasonable practice sound reckless.
— S. Tovmasyan, Gyumri
A fair objection and we have adjusted the wording. Our intention was to locate the absence with the people who could have funded the trial rather than with the clinicians managing without it, and on rereading the original paragraph did not achieve that.
On “Two-thirds back: the extension nobody expected to be the headline” — Patient Notes, 15 Aug 2024
You say no dose-equivalence data exists between agents in this class. During the shortage my pharmacy substituted one for another on the basis of a conversion table they had printed from somewhere. Where would such a table have come from?
— N. Bujanović, Sarajevo
Almost certainly from cross-trial comparison of weight-loss percentages, which is not an equivalence basis. There is no head-to-head dose-titration study permitting conversion between these agents, and STEP 8 — the only head-to-head weight trial we know of — compared two agents at their own licensed doses rather than establishing equivalence between them.
On “Two-thirds back: the extension nobody expected to be the headline” — Patient Notes, 15 Aug 2024
Your piece describes tapering as pharmacologically pointless and then spends three paragraphs making a case for it. Pick one.
— E. Vandenberghe, Ghent
Both, we think, and deliberately. There is no pharmacological rationale, because there is no withdrawal syndrome and a week-long half-life produces its own decline. There is a behavioural rationale, which is different in kind and untested. Our objection is to tapers advocated in pharmacological language, not to the practice.
On “A schedule that bends does not break” — Explainers, 12 Aug 2024
As a prescribing pharmacist I would add one thing about re-titration. The commonest problem I see is not the resumption dose. It is that the patient has a pen left over at the old strength and uses it because it is in the fridge and it cost money. The clinical decision and the economic decision are not the same decision.
— E. Marchbank, Perth, WA
Well put, and we had not written it down. The cost of discarding partially used material is a real input into dosing behaviour in a market where much of the spend is out of pocket, and it deserves treatment in The Ledger rather than a sentence here.
On “What the placebo arms of the withdrawal trials actually tell us” — The Ledger, 11 Aug 2024
You say no dose-equivalence data exists between agents in this class. During the shortage my pharmacy substituted one for another on the basis of a conversion table they had printed from somewhere. Where would such a table have come from?
— M. Karlsen, Kristiansand
Almost certainly from cross-trial comparison of weight-loss percentages, which is not an equivalence basis. There is no head-to-head dose-titration study permitting conversion between these agents, and STEP 8 — the only head-to-head weight trial we know of — compared two agents at their own licensed doses rather than establishing equivalence between them.
On “What the placebo arms of the withdrawal trials actually tell us” — The Ledger, 11 Aug 2024
As a prescriber I would push back on your framing of the maintenance gap. We are not practising without evidence; we are practising on pharmacological inference, which is what clinicians do in every field where the trial has not been run. Calling it unevidenced makes reasonable practice sound reckless.
— N. Fairweather, Hamilton
A fair objection and we have adjusted the wording. Our intention was to locate the absence with the people who could have funded the trial rather than with the clinicians managing without it, and on rereading the original paragraph did not achieve that.
On “What the placebo arms of the withdrawal trials actually tell us” — The Ledger, 11 Aug 2024
I lost access for eleven weeks during the shortage, restarted at the dose I had been on because nobody told me otherwise, and spent a fortnight unable to keep food down. I had been on that dose for seven months without difficulty. Reading your resumption section was the first time anybody explained it.
— G. Papadakis, Thessaloniki
It is entirely predictable from the label and the pharmacokinetics, and the failure to communicate it during the shortage period was systemic rather than individual. We are sorry it reached you this way and we are glad it reached you.
On “The four testing services and the study none of them can run” — Laboratory Notebook, 11 Aug 2024
Your section on freezing reconstituted solution stops short of the obvious question, which I will therefore ask. If a phosphate buffer shifts pH substantially on freezing, does that not mean the freezer is actively worse than the refrigerator for a buffered formulation, rather than merely unproven?
— F. Duquesne, Lyon
For a phosphate-buffered formulation, plausibly yes, and the mechanism is well documented. We stopped short because the magnitude is formulation-specific and because most reconstituted research vials are in unbuffered water or bacteriostatic water, where the argument is about the interface rather than about pH. We should have made that distinction in the text instead of leaving a gap for you to find.
On “The four testing services and the study none of them can run” — Laboratory Notebook, 11 Aug 2024
Eleven days in customs, and you describe it as a structural feature rather than a scandal. Why the restraint? A shipper advertising a cold chain that demonstrably does not survive a routine examination is making a claim it cannot support.
— N. Ó Broin, Sligo
The restraint is about where the fault lies. Customs authorities are performing a lawful function and owe nobody a thermal record. The claim of end-to-end control is the thing we criticise, and we do criticise it, in the article and again in the closing. What we will not do is convert an unavoidable feature of international freight into an allegation against the shipper who could not see it either.
On “Diminishing returns, quantified” — Patient Notes, 10 Aug 2024
As a prescribing pharmacist I would add one thing about re-titration. The commonest problem I see is not the resumption dose. It is that the patient has a pen left over at the old strength and uses it because it is in the fridge and it cost money. The clinical decision and the economic decision are not the same decision.
— R. Mothibi, Gaborone
Well put, and we had not written it down. The cost of discarding partially used material is a real input into dosing behaviour in a market where much of the spend is out of pocket, and it deserves treatment in The Ledger rather than a sentence here.
On “Diminishing returns, quantified” — Patient Notes, 10 Aug 2024
Your residual-exposure table gives six per cent after four weeks. I calculate 6.25 per cent, which is a quibble, but the larger point is that it assumes steady state at the moment of interruption. Someone who stops three weeks into a new rung has less on board than your table implies.
— R. Sundaresan, Coimbatore
Correct on both counts, and the table now carries the steady-state assumption explicitly. Your second point is the more useful one: interrupting mid-escalation clears faster than interrupting from a settled dose, and the practical reading of the table should be adjusted accordingly.
On “Diminishing returns, quantified” — Patient Notes, 10 Aug 2024
I want to object to the framing of dose reduction as measurement. In practice it is experienced as failure, and telling people it is a thermostat does not change how the appointment feels. The language problem is real and you have solved it rhetorically rather than actually.
— L. Marulanda, Medellín
A fair hit. We can describe the pharmacology accurately and still be writing at a distance from how the decision lands, and the paragraph you object to does both. The reframing is offered as a corrective to a stigma, not as a claim that the stigma is imaginary.
On “Diminishing returns, quantified” — Patient Notes, 10 Aug 2024
Thank you for saying plainly that the maximum dose is not the goal. I stopped at 10 mg fourteen months ago because it was working and I was tired of arguing about it. Every article I read before yours implied I had given up early.
— P. Vuković, Split
On “The area postrema, and the anatomy of an unwanted effect” — Pharmacology, 8 Aug 2024
You note that symptom burden does not predict weight outcome. This is the single most useful sentence I have read about this treatment. I spent four months believing that feeling well meant it was not working and considered increasing my dose on that basis alone.
— F. Okonjo, Asaba
The folk model that suffering indexes efficacy is widespread and the published analyses do not support it. It is also actively harmful when it drives escalation, which is why we gave it a line in the closing section rather than burying it in the tables.
On “The area postrema, and the anatomy of an unwanted effect” — Pharmacology, 8 Aug 2024
Your incidence tables are from the licensed products. I use compounded material at a concentration that does not match any pen. Are the figures transferable at all?
— P. Hollingsworth, Norwich
The mechanism transfers; the incidence figures transfer only to the extent that your actual exposure matches the trial exposure, which is unknown unless the content has been measured. That is not evasion. It is the reason we argue for peptide content as a standard reported field rather than purity alone.
On “The area postrema, and the anatomy of an unwanted effect” — Pharmacology, 8 Aug 2024
As an anaesthetist I read the perioperative section with interest and one objection. You frame disclosure as the patient obligation. In my experience the failure is more often ours: the pre-assessment questionnaire in my own institution did not include these drugs until eighteen months after the first guidance appeared.
— A. Chowdhury, Dhaka
A fair correction and we have amended the text. If the question is not on the form, the absence of an answer is not a patient failure. We would be interested to hear from readers in other institutions about whether their pre-assessment documentation has caught up.
On “The area postrema, and the anatomy of an unwanted effect” — Pharmacology, 8 Aug 2024
The gallbladder section says some of the excess is attributable to weight loss rather than the drug. If the drug causes the weight loss, is that not a distinction without a difference for the person who ends up in theatre?
— M. Bogdanović, Podgorica
For the individual, largely yes. For the question of whether one molecule is safer than another, or whether the risk would fall on slower loss, the distinction is the whole question. We should have made clear that it is a mechanistic distinction rather than a consoling one.
On “A peak with no chromophore is a peak with no peak” — Explainers, 7 Aug 2024
A small technical correction. You write that trifluoroacetic acid is used at around 0.1 per cent. In peptide work concentrations of 0.05 to 0.1 per cent are both common, and some methods run higher for particularly basic sequences. The figure reads as though it were a standard rather than a range.
— R. Mothibi, Gaborone
On “A peak with no chromophore is a peak with no peak” — Explainers, 7 Aug 2024
Your submission design has a hole in it. Eight vials from one lot cannot separate variation between laboratories from variation between vials, because you have no replicate within a laboratory to estimate the second. Two vials each is a start and it is not enough, and the honest conclusion from your table is that the four figures differ, not that the laboratories do.
— R. Sundaresan, Coimbatore
Correct, and the criticism is well aimed. With pairs we can see within-laboratory agreement, which was good in every case, but we cannot decompose the remaining variance properly. The four-condition study on a single sample was designed to isolate the method effect for exactly that reason, and it is the stronger half of the exercise. We should have said which half carried the weight.
On “A peak with no chromophore is a peak with no peak” — Explainers, 7 Aug 2024
The section on retention time and identity should be compulsory reading. I have three certificates in front of me all of which say identity confirmed and all of which mean retention-time comparison against a house standard.
— L. Marulanda, Medellín
On “A peak with no chromophore is a peak with no peak” — Explainers, 7 Aug 2024
On response factors: you say correction requires isolated impurity standards, which is true, but you might mention that charged aerosol and mass-based detection sidestep the problem by responding more uniformly. Neither is exotic any more.
— P. Vuković, Split
On “A peak with no chromophore is a peak with no peak” — Explainers, 7 Aug 2024
One practical note from the other side of the counter. When a customer asks us for the gradient we send it. When a customer asks a reseller, the reseller does not have it, because they were sent a PDF with a number on it. The gap you are describing is often two links down the chain rather than at the laboratory.
— T. Nkemelu, Port Harcourt
That is an important structural point and it changes where the fix has to happen. If the laboratory report travels intact instead of being transcribed into a house certificate, the method travels with it. Four of the twenty companies we track already attach the original report, and on this argument they are doing the single most useful thing available.
On “Target dose, effective dose, and the distance between them” — Pharmacology, 7 Aug 2024
I want to object to the framing of dose reduction as measurement. In practice it is experienced as failure, and telling people it is a thermostat does not change how the appointment feels. The language problem is real and you have solved it rhetorically rather than actually.
— M. Suárez, Montevideo
A fair hit. We can describe the pharmacology accurately and still be writing at a distance from how the decision lands, and the paragraph you object to does both. The reframing is offered as a corrective to a stigma, not as a claim that the stigma is imaginary.
On “Target dose, effective dose, and the distance between them” — Pharmacology, 7 Aug 2024
Thank you for saying plainly that the maximum dose is not the goal. I stopped at 10 mg fourteen months ago because it was working and I was tired of arguing about it. Every article I read before yours implied I had given up early.
— A. Lindholm, Gothenburg
On “Target dose, effective dose, and the distance between them” — Pharmacology, 7 Aug 2024
As a prescribing pharmacist I would add one thing about re-titration. The commonest problem I see is not the resumption dose. It is that the patient has a pen left over at the old strength and uses it because it is in the fridge and it cost money. The clinical decision and the economic decision are not the same decision.
— T. Blakemore, Hull
Well put, and we had not written it down. The cost of discarding partially used material is a real input into dosing behaviour in a market where much of the spend is out of pocket, and it deserves treatment in The Ledger rather than a sentence here.
On “Target dose, effective dose, and the distance between them” — Pharmacology, 7 Aug 2024
Your residual-exposure table gives six per cent after four weeks. I calculate 6.25 per cent, which is a quibble, but the larger point is that it assumes steady state at the moment of interruption. Someone who stops three weeks into a new rung has less on board than your table implies.
— M. Guðmundsdóttir, Reykjavík
Correct on both counts, and the table now carries the steady-state assumption explicitly. Your second point is the more useful one: interrupting mid-escalation clears faster than interrupting from a settled dose, and the practical reading of the table should be adjusted accordingly.
On “Target dose, effective dose, and the distance between them” — Pharmacology, 7 Aug 2024
I had a nine-week gap last year because my supplier stopped answering messages. Nobody in any clinical setting I dealt with treated that as a pharmacological event. Your framing of supply interruption as a dosing decision is the first time I have seen it written down.
— T. Aoyama, Nagoya
On “Residual stomach content on endoscopy: the studies” — Explainers, 6 Aug 2024
Your incidence tables are from the licensed products. I use compounded material at a concentration that does not match any pen. Are the figures transferable at all?
— E. Thistlethwaite, Sheffield
The mechanism transfers; the incidence figures transfer only to the extent that your actual exposure matches the trial exposure, which is unknown unless the content has been measured. That is not evasion. It is the reason we argue for peptide content as a standard reported field rather than purity alone.
On “Grams per kilogram of what? The denominator problem in protein guidance” — Clinical Trials, 4 Aug 2024
As a DXA technologist of twenty-two years I would add one thing to your precision section: the largest source of error in practice is not the machine, it is positioning. A patient scanned with their arms two centimetres further from their trunk will report different regional values. We are trained to a protocol and the protocol is not always followed.
— A. Basaraba, Winnipeg, MB
We should have said this and did not. It also argues for what you presumably practise: same device, same technologist, same protocol, and a note in the record when any of those changes.
On “Grams per kilogram of what? The denominator problem in protein guidance” — Clinical Trials, 4 Aug 2024
You write that no trial has measured strength. There are observational cohorts with grip strength data. Why do you insist on randomised measurement?
— P. McAlinden, Belfast
Because grip strength in an observational cohort of people who chose to take a drug, and who differ from those who did not in age, motivation and comorbidity, cannot separate the drug effect from the selection. We report those cohorts and we do not treat them as answering the question.
On “Grams per kilogram of what? The denominator problem in protein guidance” — Clinical Trials, 4 Aug 2024
Your piece treats the one-quarter rule as discredited and then quotes fractions of one third and two fifths from the substudies as though those were more solid. They are group means from a hundred and forty people. Physician, heal thyself.
— D. Chukwuma, Onitsha
A fair hit, and we have amended the paragraph to carry the same caveat in both places. The distinction we should have drawn is that the substudy figures are at least attached to a stated population and a stated instrument, which the textbook rule is not. Neither is a constant.
On “Grams per kilogram of what? The denominator problem in protein guidance” — Clinical Trials, 4 Aug 2024
I train four times a week, eat a hundred and sixty grams of protein and my appendicular lean mass has fallen by 1.8 kg over ten months while every lift has gone up. Your section on mass against function was the first thing I have read that made that seem normal rather than a failure.
— M. Sandhu, Amritsar