Clinical thyroidology november 2008 volume 20 issue 3
#OFFEE INTERFERES WITH THE INTESTINAL ABSORPTION OF LEVOTHYROXINE
"ENVENGA 3 "ARTOLONE , 0APPALARDO -! 2USSO ! ,APA $ 'IORGIANNI ' 3ARACENO '4RIMARCHI & !LTERED INTESTINAL ABSORPTION OF,THYROXINE CAUSED BY COFFEE4HYROID
35--!29 "!#+'2/5.$ -ANY THINGS INTERFERE WITH LEVOTHYROXINE ,4 ABSORPTION SUCH AS IRON BILE ACIDnBINDING RESINS
CHOLESTYRAMINE AND COLESTIPOL OVERTHECOUNTER DRUGSCONTAINING IRON AND CALCIUM GASTRIC CONDITIONS SUCH ASACHLORHYDRIA AND FOOD INGESTION AROUND THE TIME ,4 IS
TAKEN 4HE AUTHORS OF THIS STUDY HAVE PREVIOUSLY REPORTEDCASES OF DELAYED INTESTINAL ABSORPTION OF ,4 AND HAVE THUS
BEEN MORE THAN USUALLY ATTENTIVE TO THIS PROBLEM ELICITINGDETAILED HISTORIES FROM THEIR PATIENTS ABOUT THE USE OF OTHERDRUGS AND THE DIETARY HABITS PATIENTS FOLLOW WHEN TAKING ,4
0RIMARY PHYSICIANS REFERRED PATIENTS WHO WERE TAKING ,4
FOR REPLACEMENT THERAPY OR TO SUPPRESS SERUM THYROTROPIN43( THAT FAILED TO PRODUCE THE EXPECTED RESULTS 4HEAUTHORS FOUND THAT SEVERAL PATIENTS WERE CONSISTENTLY DRINKINGCOFFEE OR ESPRESSO TO FACILITATE SWALLOWING THEIR ,4
&IGURE 4 ABSORPTION IN THE ACUTE LOADING TEST OF «G OF ORAL 4
IN FOUR DIFFERENT METHODS OF INGESTION "RAN WAS INGESTED BY ONLY TWO
WERE TAKING ,4 WITH WATER FOLLOWED SHORTLY BY DRINKING
PATIENTS !5# IS AREA UNDER THE CURVE FOR 4
COFFEE OR ESPRESSO SUGGESTING THAT THIS MIGHT BE THE CAUSE OF
WITH CONTROLS DRINKING WATER ALONE WITH ,4 o0 COMPARED WITH
-%4(/$3 4HE STUDY SUBJECTS WERE EIGHT PATIENTS ALL OFWHOM WERE WOMEN 4HEIR MEAN ¢3$ AGE WAS ¢YEARS RANGE TO AND THEIR SERUM 43( LEVELS WERE¢ M)5, RANGE TO 4EN HEALTHY VOLUNTEERSFOUR MEN AND SIX WOMEN AGED TO YEARS WERE ALSOSTUDIED 0ATIENTS AND VOLUNTEERS UNDERWENT IN VITRO STUDIESOF INTESTINAL ,4 ABSORPTION USING AN ORAL DOSE OF ,4 IN LIEU
OF RADIOISOTOPIC TECHNIQUES )NSTEAD OF USING * «G OF ,4
FOR THE TEST WHICH IS THE USUAL DOSE FOR THIS PURPOSE PATIENTSAND VOLUNTEERS WERE GIVEN TWO «G ,4 TABLETS WITH
APPROXIMATELY ML OF WATER TO FACILITATE SWALLOWING WHICHWAS THE BASELINE STUDY ! SECOND TEST SUBSTITUTED ESPRESSOn ML FOR WATER WHILE INGESTING ,4AND A THIRD TEST USED
WATER ALONE TO FACILITATE ,4 SWALLOWING FOLLOWED HOUR LATER
BY ESPRESSO 4HE STUDIES WERE REPEATED TO WEEKS LATERAND AGAIN AFTER ANOTHER TO WEEKS ALTHOUGH IN THE LAST TESTS
&IGURE $ATA FOR VOLUNTEERS 3EE &IGURE EXPLANATION
0 ANDo0 FOR RESULT VS WATER ALONE
THE SEQUENCE OF WATER AND ESPRESSO WAS RANDOM4O FURTHERTEST THE IN VIVO EFFECTS OF KNOWN INHIBITORS OF ,4 INTESTINAL
2%35,43 4HE MAIN IN VIVO lNDINGS OF INTESTINAL 4
ABSORPTION TWO PATIENTS AND TWO VOLUNTEERS EACH INGESTED
ARE SHOWN IN &IGURES TO 4AKING «G OF ,4
TWO PACKETS OF BRAN DISSOLVED IN ML OF WATER WHEN THEY
DRINKING ESPRESSO SIGNIlCANTLY LOWERED THE AVERAGE SERUM 4
OR ML OF ALUMINUM HYDROXIDE PLUS MAGNESIUM
HYDROCHLORIDE -AALOX MINUTES AFTER SWALLOWING «G
4HE IN VITRO EXPERIMENTS WERE DONE BY COMBINING A
AREA UNDER THE CURVE BUT THIS WAS NOT SIGNIlCANTLY
DIFFERENT FROM THAT FOUND IN THE CONTROL OBSERVATIONS $RINKING
-AALOX OR WITH SUCRALFATE OR DIETARY lBERS OF BRAN
#,).)#!, 4(92/)$/,/'9 L ./6%-"%2
ESPRESSO HOUR AFTER TAKING ,4 HAD NO SIGNIlCANT EFFECT ON
,4 INTESTINAL ABSORPTION (OWEVER THE DECREASE IN ,4
ABSORPTION WITH SIMULTANEOUS ,4 AND ESPRESSO INGESTION
WAS NOT AS GREAT AS WITH ,4 AND BRAN &IGURES AND OR
,4 WITH -AALOX &IGURE 4HESE EFFECTS WERE SEEN IN BOTH
PATIENTS AND VOLUNTEERS &IGURES TO 4HE IN VITRO STUDIESTHAT TESTED THE RECOVERY OF 4 FROM A SOLUTION CONTAINING A
KNOWN CONCENTRATION OF 4 FOUND THAT ESPRESSO WAS FOLD
TO FOLD WEAKER THAN BRAN AND TO FOLD WEAKER THAN-AALOX IN LOWERING THE 4 CONCENTRATION IN THE SOLUTION
#/.#,53)/. $RINKING COFFEE OR ESPRESSO AT THE TIME ,4
IS TAKEN INTERFERES WITH THE INTESTINAL ABSORPTION OF ,4
&IGURE 4 INDEX DATA FOR ONE VOLUNTEER
#/--%.4!29
TO REGULAR COFFEE &OR INSTANCE THE EFFECTS OF COFFEE ON THEGASTRIC EPITHELIAL CELLS DIFFER ACCORDING TO DIFFERENT ROASTING
4HIS STUDY CLEARLY SHOWS THAT DRINKING ESPRESSO OR COFFEE
METHODS AND DIFFERENT COFFEES AND MAY VARY IN THEIR EFFECT
MAY INTERFERE WITH INTESTINAL ABSORPTION OF ,4 IF ONE DRINKS
ON THE INTESTINAL MUCOSA 3TILL ALL EIGHT PATIENTS HAD
IT WITH OR SHORTLY AFTER LEVOTHYROXINE IS TAKEN 4HIS PATTERN
43( LEVELS IN THE THERAPEUTIC RANGE AFTER BEING INSTRUCTED
OF TAKING ESPRESSO OR COFFEE WITH ,4 WAS HIGHLY CONSISTENT
TO REFRAIN FROM DRINKING COFFEE AND TO ABSTAIN FROM EATING
AMONG THE EIGHT STUDY PATIENTS 4HE EFFECT WAS SIGNIlCANT
FOR MINUTES AFTER TAKING ,4 #OFFEE DOES NOT CHANGE THE
BUT IS NOT AS SEVERE AS THAT PRODUCED BY -AALOX OR BY BRAN
GASTRIC P( NOR DOES IT IMPAIR GASTRIC EMPTYING AND INTESTINAL
INGESTED AT THE TIME ,4 IS TAKEN4HE EFFECT OF ESPRESSO WAS
TRANSIT IN NORMAL VOLUNTEERS "ECAUSE THE "ENVENGA STUDY IS
OBVIATED BY DRINKING IT MINUTES AFTER TAKING ,44HE STUDY
RETROSPECTIVE IT RELIED ON THE RECOLLECTIONS OF PATIENTS RATHER
ALSO SHOWS THAT ESPRESSO SEQUESTERS ,4 IN VITRO ALTHOUGH
THAN A SYSTEMATIC RECORDING OF THE TIMING OF MEALS AND COFFEE
ONE OF THE VOLUNTEERS HAD AN INCREASE IN THE ABSORPTION OF
INGESTION 3TILL THE OBSERVATIONS ARE STRONG ENOUGH AND
,4 WITH COFFEE INGESTION4HE MECHANISM BY WHICH ESPRESSO
THE RECOMMENDATIONS ARE SIMPLE ENOUGH TO MERELY WARN
DECREASES ,4 ABSORPTION IS UNCERTAIN BUT THE AUTHORS OPINE
PATIENTS ABOUT THIS PROBLEM AND TO ADD COFFEE TO THE LIST OF
THAT IT ACTS BY SEQUESTERING ,4 RENDERING THE HORMONE LESS
THINGS TO BE AVOIDED AT THE TIME THAT ,4 IS TAKEN
AVAILABLE FOR UPTAKE BY INTESTINAL EPITHELIUM !LSO ALL THE INVIVO STUDIES WERE DONE WITH ESPRESSO AND NOT COFFEE PER SE
RAISING SOME CONCERNS THAT THESE lNDINGS MIGHT NOT APPLY
&IEBICH ",6ALENTE 0 &ERRER-ONTIEL ! ET AL %FFECTS OF COFFEESBEFORE AND AFTER SPECIAL TREATMENT PROCEDURE ON CELL MEMBRANEPOTENTIALS IN STOMACH CELLS -ETHODS &IND %XP #LIN 0HARMACOL
%HRLICH ! "ASSE ( (ENKEL%RNST * ET AL %FFECT OF DIFFERENTLYPROCESSED COFFEE ON THE GASTRIC POTENTIAL DIFFERENCE ANDINTRAGASTRIC P( IN HEALTHY VOLUNTEERS -ETHODS &IND %XP #LIN0HARMACOL
#,).)#!, 4(92/)$/,/'9 L ./6%-"%2
Dr Frances Pitsilis – 2A Dodson Avenue, Milford, Auckland PO Box 31-572, Milford, North Shore City 0741, New ZealandPHONE: +64 9 486 0030 FAX: +64 9 486 0333 EMAIL: info@drfrances.co.nz WEBSITE: www.drfrances.co.nz TOO MUCH OF A GOOD THING? As the warm weather and summer approaches and we are all looking forward to getting more sunshine, feeling a bit brighter that the better weather brings
*This program is supported by Salix. Neither Mayo • Microscopic colitis used as umbrella term -subsets collagenous, lymphocytic colitis• Unclear if distinct or parts of a spectrum Which of the following is true regarding patients with microscopic colitis? A) Abdominal pain is uncommon B) Weight loss is uncommon C) Fecal leukocytes are uncommon D) Most meet Rome criteria for