Testing
Drug Study
Your Help Is Needed
Dr. Karl Anderson's porphyria laboratory at the University of Texas
Medical Branch (UTMB) and Dr. Herbert Bonkovsky at the University
of Connecticut have a long-standing interest in studying the
effects of drugs on induction of heme synthesis in the chick
embryo liver system. Induction
observed in this model predicts whether a drug under study is likely to have
the capacity to induce an exacerbation of acute porphyria. However, this
and other laboratory animal and cell culture systems are imperfect in predicting
whether a drug is safe or harmful for patients with porphyria. Therefore,
they are undertaking an observational study of the effects of drugs on patients.
This study will supplement and not replace studies in model systems, and
they will continue our interest in testing drugs in the chick embryo liver.
Many patients with acute porphyrias are prescribed drugs for which
there is insufficient information as to safety for use in porphyria.
At present, this rather extensive experience on drug use is not monitored
or recorded. Recording some of this experience prospectively would
provide guidance as to whether specific drugs are likely to be safe
or harmful. This experience would supplement studies done in laboratory
models such as the chick embryo liver. They propose to record the
experience of patients with acute porphyrias who take drugs for various
medical conditions, as prescribed by their own physicians.
Patients or their physicians would be encouraged to contact them
before taking the drug. If the drug is already known to be unsafe,
the patient or physician would be advised not to use the drug unless
there is an over-riding clinical indication and no suitable alternative
treatment option is available. Information would be obtained regarding
documentation of the diagnosis of porphyria, and, if necessary, additional
testing would be advised. Patients with well-documented acute porphyria
would be asked to submit a spot urine sample before starting the
drug, and then again one, two and four weeks after the drug. These
samples would be shipped to the laboratory at UTMB.
Porphyrin and porphyrin precursor concentrations would be measured
and expressed per gram of creatinine. Symptoms would be recorded
for one month before and after starting the drug. Information on
patients with latent porphyria (defined as being asymptomatic for
at least one year and with normal urinary porphyrin precursors and
porphyrins) would be recorded separately from patients with a history
of recent symptoms and increased urinary values. The researchers
anticipate that the recording of such experience for any given drug
in 20 patients with well-documented acute porphyria will provide
useful guidance for the use of this drug in additional patients in
the future. The information they collect will provide better guidance
regarding drugs being safe or harmful in porphyria. Many such reports
are conflicting, and the documentation that some of the patients
have acute porphyria is often insufficient.
If you would be willing to participate
in this study, please contact Desiree Lyon at the APF office 713-266-9617
or porphyrus@aol.com.
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