Porphyrinemia and Porphyrinuria: A Warning Regarding Their Importance in Roentgen Therapy

Abstract

HOW many radiologists recognize the importance of porphyrinemia and porphyrinuria and the possible source of danger in the sensitization, by means of drugs, of the tissues to light? How many of you have had your attention called to this subject at any time? Because of the rather recent introduction of hematoporphyrin (commercially known as Photodyne and other names) into general use in medical therapeutics, particularly in neuropsychiatry in the treatment of melancholia and allied depressive conditions, and the decidedly too promiscuous taking and prescribing of barbituric acid derivatives as sleeping powders, it is altogether likely that some radiologists may have reason to wonder why erythemas appear after moderate or even mild dosage. I am calling your attention to this subject because I have had that experience myself and have been called to help another radiologist who had a scare because of the same thing. As the result of a series of experiments with hematoporphyrin, to determine its photobiologic properties and effects, Hausman1 reported, in 1916, that by hypodermatically injecting solutions of that agent, white mice, rats, and guinea pigs were rendered so highly sensitive to light that when they were exposed to it they became toxic and died; but when these same injected (control) animals were kept in the dark they were apparently unaffected. Huehnerfeld2 and others later reported that while animals so treated showed marked photodynamic effects when the hematoporphyrin was injected under their skin, no such effects resulted when the drug was administered orally, except when large doses were given. Rats fed with large doses became toxic and died within three or four hours after being exposed to bright sunlight. These rats showed fatty degeneration of central liver lobules, hyperemia of the skin and other pathology. Meyer-Betz,3 while experimenting with hematoporphyrin, administered 0.2 gm. under his own skin and then irradiated an area on his arm with a Finsen lamp, with a resulting ulceration in the irradiated area. Two months later he suffered a “light stroke,” with the production of giant edema and deep pigmentation of the skin. While the literature of the manufacturers of hematoporphyrin claims that this drug has no harmful effects, the proven fact that it sensitizes (and causes a sensitization) to light makes it very much worth our while to keep it in mind, because of the potential danger to our patients. What appears to be more important to us as radiologists is that in addition to hematoporphyrin, many commonly used sedatives, such as sulphonal, luminol, and other barbituric acid derivatives produce porphyrinemia and porphrynuria, with the resultant sensitization to light and irradiation. These agents also cause itching, which occuring simultaneously with and accompanying skin redness is decidedly liable to give the unwary radiologist unpleasant insomnia and additional gray hairs.