RÉGIS NETO, J.; http://lattes.cnpq.br/6754335154583540; RÉGIS NETO, José.
Résumé:
Proton pump inhibitors (PPI) are the most prescribed and without prescription
class of drugs used for heartburn and gastroesophageal reflux disease (GERD).
Among patients using levothyroxine (LT4),this is the most common drugs
coadministration.
We performed a randomized blind trial to access the effect of a standard PPI
Omeprazole® in levothyroxine (LT4) absorption, varying its dosage and
administration interval. A total of 63 patients, mean age 48,9 years the great
majority females (89%), were allocated in 5 groups during 8 weeks (Placebo;
LT4+PPI 20mg with 30 and 60min interval; LT4+PPI 40mg with 30 and 60min
interval). Inclusion criteria included a stable dose of LT4 for one year and
controlled parameters of thyroid function accessed before the use of PPI(serum
FT4 and TSH).
Patients in the groups who received PPI 20mg 30min, PPI 40mg 30 and 60min
after the LT4 presented a statically significant increasing in TSH levels. Only the
group LT4+40mg of PPI 30min after showed significant decrease in FT4(p=0,01).
Most patients have not reached high enough values in need of adjustment in
dosage of LT4, possibly a reflection of the trial short interval.
Many studies failed in demonstrate the ideal interval between the use of these
drugs and either if the dosage and this fasting time has any interference in LT4
absorption.In this trial, we concluded that the greater the dosage od PPI used,
greater the absorption interference, and TSH levels increases more significantly
the shorter the interval between the drugs administration.