A study on the neurotoxicity of broxyquinoline and brobenzoxaldine combination in therapeutic doses.

The neurotoxicity of a combination of broxyquinoline and brobenzoxaldine (Intestopan Forte, containing 500 mg and 100 mg of the drugs respectively per capsule) was investigated by prospective clinical and electrophysiological studies in patients and volunteer subjects given the drugs in therapeutic doses (two capsules three times a day for 5 days). Of 16 patients with intestinal amoebiasis given the drugs (study A), 13 (81.25%) were cured. Adverse effects were mild and did not affect treatment. No neurological adverse effect was reported. Neurological examinations revealed no abnormality in any patient after treatment. Seven volunteer subjects underwent medical, neurological and ophthalmological examinations, and electrophysiological studies of ulnar and peroneal nerve conduction before and after treatment with the drugs in therapeutic doses (study B). Transient paresthesias were reported by one subject on the fourth day of treatment. No medical, neurological or ophthalmological abnormality was detected in any subject after treatment. There was no significant change in motor nerve conduction velocities. There was a significant (P less than 0.001) increase in the stimulus strength for distal ulnar stimulation and a significant (P less than 0.01) decrease in stimulus duration for proximal and distal ulnar stimulation. No significant changes were seen in the peroneal nerves in these parameters. No qualitative abnormality was seen in the oscilloscopic patterns of nerve conduction after treatment. Literature on the neurotoxicity of the halogenated hydroxyquinolines is reviewed. It is concluded that broxyquinoline and brobenzoxaldine (and probably other halogenated hydroxyquinolines as well) are safe and effective in therapeutic doses; neurotoxicity is unlikely to occur when these drugs are used according to therapeutic recommendations.

[Occupational dermatitis due to a yellow quinophthalone dye (solvent yellow 33: C.I. 47 000)]. / Berufsbedingtes Kontaktekzem durch gelben Chinophthalonfarbstoff (Solvent Yellow 33; C.I. 47 000).

An occupational allergic contact dermatitis caused by a yellow quinophthalone dye which is used for colored smokes in detonators was the reason for further studies of this case of allergy. Solvent Yellow 33 (German: Rauchgelb) belongs to the groups of quinaldine dyes which are produced by condensing quinaldine and phthalic anhydride. The dye itself is a mixture of 67% unsubstituted quinophthalone and 33% 6-methylquinophthalone (Colour Index 47 000). Quinophthalone derivatives are widespread in technology and industry and are used as yellow dyes in food (pudding), plastics (PVC), textile goods (nylon) and cosmetics (lipsticks, make-up). Cases of contact sensitization due to quinophthalone dyes are seldom recognized. Sensitizing experiments in guinea pigs were unsuccessful. Therefore Solvent Yellow 33 must be considered a weak sensitizer.