ETA guidelines for levothyroxine monotherapy in hypothyroidism
Centanni M, Duntas L, Feldt-Rasmussen U, Koehrle J, Peeters RP, Razvi S, Trimboli P, Virili C
The finding, in our words
Task-force guideline on optimising levothyroxine monotherapy. After a change of dose it advises measuring free T4 and TSH at six weeks. It attributes the slow response to the long half-life of T4 and the delayed TSH reaction without giving either a number. On dosing routine, taking the tablet with breakfast produced the highest and most variable TSH of three regimens, while an hour before breakfast or at bedtime kept TSH inside the reference interval.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
A 2025 review maps 28 microsampling devices, from dried spots and volumetric absorptive tips to upper-arm liquid capillary collectors, and names what a laboratory must control before their results are used: the haematocrit effect in non-volumetric dried samples, interstitial fluid from finger milking, volume, haemolysis and transport stability. Regulators on both sides of the Atlantic ask for the same two things, a device the patient can use safely and a sample fit for the test.
In 20,019 outpatient TSH samples drawn between 07:00 and 15:00, mean TSH fell from 2.76 mIU/L at 07:00-09:00 to 2.22 mIU/L at 13:00-15:00, about 28% across the day, with the steepest decline before 09:00. Against the 4.0 mIU/L upper reference limit, 14.1% of patients were above it at 07:00-08:00 and 7.9% at 14:00-15:00, so 6.2% changed side of the decision limit on sampling time alone. Resting time before sampling had no clinically significant effect on TSH, albumin, calcium or sodium.
Andersen IB, Brasen CL, Christensen H, Noehr-Jensen L, Nielsen DE, Brandslund I, Madsen JS, PLoS One · source ↗
Guidance on capillary-to-plasma conversion: method- and analyte-specific clinical validation with paired capillary–venous samples before reporting plasma-equivalent results.
Boffel et al., Therapeutic Drug Monitoring (paywalled) · source ↗
Home DBS sampling gave testosterone results that agreed well with venous blood in men on intramuscular testosterone undecanoate, but showed falsely high values in those using topical gel, likely from skin contamination. Patients preferred home collection for its convenience, suggesting DBS is viable for decentralised monitoring of injectable testosterone if patients are taught proper technique.
Olthof et al., Clinical chemistry and laboratory medicine (paywalled) · source ↗
The authors observe that self-sampling devices for capillary blood are gaining traction as a patient-preferred alternative to venous collection, with one centre reporting a 15 percent reduction in laboratory test volumes when local collection was offered. They argue that successful integration into total laboratory automation requires addressing cost, transport regulations and sample volume adequacy while ensuring robust device design and seamless workflow compatibility.
Poland & Cobbaert, Clinical chemistry and laboratory medicine (paywalled) · source ↗