Methonium compounds in hypertension / W.D.M. Paton, J. Walker.

  • Paton, William D. M.
Date:
[1951?]
Catalogue details

Licence: In copyright

Credit: Methonium compounds in hypertension / W.D.M. Paton, J. Walker. Source: Wellcome Collection.

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    Letter to the Editor reprinted from The Lancet, February 24, 1951, p. 473 METHONIUM COMPOUNDS IN HYPERTENSION Sir,—After Kay and Smith 1 observed that the potency of the halide salts of hexamethonium given orally, expressed in terms of the cation, was highest for the iodide and lowest for the chloride, with the bromide intermediate, clinical studies of this drug have been made mostly with the bromide or iodide. It seems improbable, however, that the halide anion of such a salt, which must be completely dissociated in solution, can exert any significant effect on the activity of the hexamethonium cation, or even on its absorption. In view of the possibilities of bromism2 and of iodism from the use of the bromide or iodide, we have been prompted to test the purity of some of the available preparations in order to determine whether the reputed inefficacy of the chloride was associated with any impurity ; and to verify whether, with pure salts, the biological activity of the cation did indeed varv with the different halide ions. We have determined the halide content of samples of hexamethonium salts, and have assayed biological activity, using the antagonism of hexamethonium to the action of acetylcholine on the frog’s rectus abdominis (limits of error 7-10%, P = 0-05). The results were as follows : II examethoniu m salt 1. Iodide . . 2. Iodide . . 3. Iodide . . 4. Bromide 5. Bromide 6. Chloride 7. Chloride Biological activity 93 100 100 90 100 80 97 Halide content ( % theoretical) 94 99 100 94 99 84 99 Biological potency is given (in terms of the cation) as percentage of that of the pnre iodide (Salts 2 and 3). It will be seen that biologically several of the salts were below theoretical potency, and that in each case 1. Kay, A. W., Smith, A. N. Brit. med. J. 1950, ii, 807. 2. Rosenheim, M. L. Lancet, Feb. 10, 1951, p. 347. Holt, M. C., Litchfield. J. W. Ibid.