Læknablaðið : fylgirit - 01.05.1978, Qupperneq 68

V.
As to be expected for such a diagnostically
inhomogeneous group as the present one, most
of the patients were being treated with other drugs.
This drug treatment was not suspended during the
urine collection, but on inspection of the data there
appears to be no relation between a positive test
for 5-hydroxyindole in urine and any of the otheí
drugs.
Mr. Göran Berglund of Asta Syntex has informed
me that in Bergen 5-hydroxyindole was found in
the urine of a patient receiving naproxen treat-
ment. Further investigation indicated that this
was due to the method used and the way it was
employed in practice.
The method used in the present investigation
to determine 5-hydroxyindoles in urine is the
Udenfrid, Titus, Weissbach-method. It
measures 5-hydroxytryptophan, 5-hydroxytrypta-
mine (serotonin) as well as 5-HIAA.
To test the reliability of the method and to
see if false positives do occur, all the results
of 1975 were reviewed. The test had been
carried out 90 times on 71 patients. It was
positive 13 times for 3 patients. One of these
was the first patient in the group presented
here. Another was an 85 year old woman, who
was under observation because of abdominal
cramps and diarrhea. Inspection of her record
revealed that at the time of the test she was
being treated with naproxen for osteoarthritis.
The third patient was a 35 year old woman who
when examined as an outpatient gave a dubious
positive test. The test was repeated the fol-
lowing day and again 6 weeks later with negative
results. There is no information available on
this patients intake of drugs.
All the tests were carried out by the same
laboratory technician, and on the basis of this
information the test does not appear to have
given false positives previously. It therefore
seems fair to conclude, that tlie naproxen intake
by these patients has influenced the 5-hydroxy-
indole test. In that case there could be either
a question of a naproxen metabolite interfering
with the test or a real increased 5-hydroxyindole
excretion, either because of increased production
or decreased protein binding due to competition.
I can not say whether this could cause
carcinoidsyndrome - like symptoms. The first
patient maintained that her symptoms decreased
when she stopped taking naproxen, but perhaps
did not disappear completely, at least not the
high temperature periods.
Another positive patient complained of tachycardia
without there being any definite connection with
naproxen intake. The other patients showed no
carcinoid syndrome-like symptoms.
I cannot say why only half of the patients gave
a positive test for 5-hydroxyindole in urine. On
the whole I think the present investigation raises
more questions than it answers. What is the
serum concentration of serotonin during naproxen
treatment? What is the 5-hydroxyindole excretion
of healthy persons under doubleblind test condi-
tions etc. etc. ?
It appears to me that the only conclusion to
be drawn from these observations is that for
the time being naproxen treatment should be
suspended before the urine of patients is tested
for 5-hydroxyindoles using this method.
Day
36
Vlsken 30 mg/d
Valium 15 mg/d
Celeston 0,25 mg/d
Taractan 15 mg/d
Mogadon
Naproxen 375 mg/d
up to day 9, then
■8S
co co
!b ro
Mg 5-HIAA/g creatine/d ^ ^
EXCRETION OF 5-HIAA IN URINE
M J (j> 52 years old
66