Cardiovascular Depressant Effects of Neomycin and Gentamicin in Rhesus Monkeys

Are the cardiovascular effects of gentamicin similar to those of calcium antagonists?

“…The present results are thus consistent with those of previous in vestigators, i.e., hypotension (due to vasodi latation) (8-10, 20), reduction of vascular resistance (10), relaxation of vascular smooth muscle (21,22), reduction of the force of contraction of cardiac muscle (10,11,20,23,24) and bradycardia (20). The present experiments further disclosed that GM impairs AV nodal conduction.…”

Gentamicin blockade of slow Ca++ channels in atrial myocardium of guinea pigs.

“…If present findings with an isolated heart muscle model relate to other excitable tissues, then an interference by aminoglycoside antibiotics with Ca++ influx across cell membranes may well explain the depressant properties of these drugs previously observed in a variety of functionally related and unrelated tissues in both man and lower animals (1)(2)(3)(4)(5)(6)(7)(8)(9). Importantly, present observations also provide a mechanistic explanation for cardiac irregularities occasionally detected in patients treated with aminoglycoside antibiotics (4,(21)(22)(23).…”

“…These agents, in addition to their useful antibacterial activity, also (a) inhibit synaptic transmission at various neuroeffector junctions (1,2), (b) depress cerebral neuron responses to catecholamines (3), (c) depress cardiovascular function (4)(5)(6)(7)(8), and Received for publication 11 November 1977 and in revised form 2 February 1978. (d) relax different types of smooth muscles (5,9). Although the precise mechanisms responsible for these varied events have not been completely resolved, a Ca++ antagonistic property of the aminoglycosides has been proposed for many years (1).…”

A Comparison of the Myocardial Depressant Effects of Several Aminoglycoside Antibiotics

“…Previous investigations have shown that aminoglycoside antibiotics probably exert their cardiac effects through an inhibition of Ca++ movements across the sarcolemma of contracting myocardial cells: thus, calcium chloride was found to reverse streptomycin and dihydrostreptomycin-induced failure in the isolated dog heart [Swam et al, 1956], while injected during the peak depressant effect of neomycin it produced a rapid and maintained restoration of cardiovascular function in anesthetized rhesus monkeys [Adams, 1975b], These alterations of Ca++ movements were also demonstrated in vas cular smooth muscle for neomycin [Good man et al, 1974], streptomycin, kanamycin and gentamicin . A ^-adrenoceptor blocking action is untenable since propanolol and gentamicin exerted dissimilar effects on inotropic responses to isoproterenol [Adams and Durrett, 1978].…”

“…The myocardial depressant effects of aminoglycoside antibiotics have been repeti tively assessed in various animal systems: isolated guinea pig atria [Adams and Durrett, 1978], rat atria [Adams, 1975a;Sohn and Katz, 1978], rabbit hearts [Leaders et al, 1960], dog hearts [Swain et al, 1956], rabbit aortic strips Goodman et al, 1974], open-chest dogs [Cohen et al, 1970] and anesthetized rhesus monkeys [Adams, 1975b], Heart contractil ity thus has been shown to be depressed by streptomycin, neomycin, kanamycin or gen tamicin. Although previous workers have 3 With the technical assistance of R. Tedone. stressed the potential risk for cardiac acci dents with these substances, particularly in the critically ill [Daynes, 1974], no data is currently available, to our knowledge, on the possible cardiac effects of more recent derivatives.…”