ISSN:
1432-1041
Keywords:
tyramine
;
noradrenaline
;
phenylephrine
;
pressor response test
;
re-uptake
;
adrenergic receptor
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Medicine
Notes:
Summary Tyramine, noradrenaline and phenylephrine pressor response tests were performed in patients suffering from affective disorders during various drug therapies or following electroconvulsive therapies (ECT). Tricyclic and related antidepressive drugs produced decreased tyramine sensitivity and increased noradrenaline sensitivity as expected from their usual characteristic to inhibit the neuronal noradrenaline reuptake mechanism. These drugs also block the post-synaptic adrenergic receptors which was indicated by decreased phenylephrine sensitivity. However, the degree of blockade was variable and some of the newer drugs, in the dosage used, were devoid of these peripheral interactions. No significant change in these pressor response tests were observed in patients who had 3 or more ECT. On the other hand, patients treated with lithium carbonate for 4 or more weeks, had decreased phenylephrine and noradrenaline sensitivities, which were not associated with any change in tyramine sensitivity. It was postulated that lithium not only increased the neuronal amine uptake, but also decreased the sensitivity of the α-adrenergic receptors. Treatment with haloperidol for 48 h decreased 2.5 times tyramine sensitivity, which could be due to postsynaptic receptor blockade or inhibition of amine reuptake process, or both. Since no noradrenaline or phenylephrine sensitivity was determined, it was difficult to be precise. The pressor response tests were shown to be safe, reproducible, and reliable in providing informations regarding peripheral adrenergic interactions. It was suggested that all these 3 pressor response tests should be performed, otherwise incomplete or erroneous conclusions may be drawn.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00625795
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