Lack of evidence of neurotoxicity following 8 weeks of treatment with tripotassium dicitrato bismuthate.
OBJECTIVE
To search for evidence of subclinical neurotoxicity in patients treated with tripotassium dicitrato bismuthate.


METHODS
Prospective, controlled, triplicate study using urinary bismuth concentration, magnetic resonance imaging (MRI), nerve conduction studies, visual evoked response and a battery of 10 neuropsychological screening tests.


METHODS
Out-patient clinics, Walsgrave Hospital, Coventry, UK.


METHODS
Fourteen dyspeptic patients; 8 (treatment group) treated with tripotassium dicitrato bismuthate one tablet q.d.s and 6 (control group) treated with ranitidine 150 mg b.d. for 8 weeks.


METHODS
Changes in urinary bismuth, MRI, nerve conduction studies, visual evoked response, and neuropsychological tests performed before, immediately after and 8 weeks after the cessation of treatment.


RESULTS
In the treatment group the median (range) urinary bismuth concentration was 1 (1-12) ng/ml before treatment, increased to 560 (140-1300) immediately after treatment (P < 0.01, Wilcoxon Rank Sum test) and was still significantly elevated (23 (7-53) ng/ml) 8 weeks after the cessation of treatment. In the patient who recorded the highest urinary bismuth, a high intensity signal appeared in the globus pallidus immediately after treatment and was still present (though diminished in intensity) 8 weeks after the cessation of treatment. This isolated MRI finding was not associated with evidence of subclinical neurotoxicity. No changes in the MRI, nerve conduction studies, visual evoked response and neuropsychological tests were observed among the other patients studied.


CONCLUSIONS
Bismuth accumulation occurs in patients receiving a conventional course of treatment with tripotassium dicitrato bismuthate but this is not associated with significant changes in the nervous system.
Nwokolo
C U
CU
Department of Gastroenterology, Walsgrave Hospital, Coventry, UK.
Fitzpatrick
J D
JD
Paul
R
R
Dyal
R
R
Smits
B J
BJ
Loft
D E
DE
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001729:Bismuth / Q000009:adverse effects* / Q000652:urine; D001921:Brain / Q000187:drug effects*; D004576:Electromyography / Q000187:drug effects; D005074:Evoked Potentials, Visual / Q000187:drug effects; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009420:Nervous System / Q000187:drug effects*; D009431:Neural Conduction / Q000187:drug effects; D009942:Organometallic Compounds / Q000008:administration & dosage / Q000009:adverse effects*; D011446:Prospective Studies; D011597:Psychomotor Performance / Q000187:drug effects
D000897:Anti-Ulcer Agents; D009942:Organometallic Compounds; C002791:bismuth tripotassium dicitrate; D001729:Bismuth