Sympathomimetics sympathomimetic

Tetrahydro2oline [84-22-0] 2-(l,2,3,4-tetrahydro-l-naphthyl)2-imida2olin, (Tysine, Visine) (40), a sympathomimetic and nasal decongestant, is made by the condensation of 1,2,3,4-tetrahydro-l-naphthoic acid or its methyl ester with 1,2-ethylenediamine. 

As of the mid-1990s, use of MAOIs for the treatment of depression is severely restricted because of potential side effects, the most serious of which is hypertensive crisis, which results primarily from the presence of dietary tyramine. Tyramine, a naturally occurring amine present in cheese, beer, wine, and other foods, is an indirecdy acting sympathomimetic, that is, it potently causes the release of norepinephrine from sympathetic neurons. The norepinephrine that is released interacts with adrenoceptors and, by interacting with a-adrenoceptors, causes a marked increase in blood pressure the resultant hypertension may be so severe as to cause death. 

Normally, dietary tyramine is broken down in the gastrointestinal tract by MAO and is not absorbed. In the presence of MAOI, however, all of its potent sympathomimetic actions are seen. Other side effects of MAOI include excessive CNS stimulation, orthostatic hypotension, weight gain, and in rare cases hepatotoxicity. Because the monoamine oxidase inhibitors exhibit greater toxicity, yet no greater therapeutic response than other, newer agents, clinical use has been markedly curtailed. The primary use for MAOIs is in the treatment of atypical depressions, eg, those associated with increased appetite, phobic anxiety, hypersomnolence, and fatigues, but not melancholia (2). 

Appetite suppressants have been widely used as an adjunct to dietary restriction and sympathomimetic amines have traditionally been used for this purpose. These agents have not proven particularly useful and frequentiy cause unacceptable side effects, hence their popularity has been waning for several years. The most promising newer dmgs work through a serotoninergic mechanism and hold considerable promise at least for certain obese patients. 

The sympathetic or adrenergic nervous system operates in juxtaposition to the parasympathetic nervous system to maintain homeostasis in response to physical activity and physical or psychological stress. Sympathomimetic neurotransmission is generally mediated by norepinephrine [51-41 -2] (1), CgH NO, released from presynaptic storage granules upon stimulation. A second endogenous sympathomimetic agent, epinephrine [51-43-4] (2),... 

Compounds stmcturaHy related to the endogenous sympathomimetic amines epinephrine and norepinephrine have classically been employed as appetite suppressants. These agents, of which amphetamine [300-62-9], is the prototypical example, generally retain the phenethyl amine, but lack... 

Some P-adrenoceptor blockers have intrinsic sympathomimetic activity (ISA) or partial agonist activity (PAA). They activate P-adrenoceptors before blocking them. Theoretically, patients taking P-adrenoceptor blockers with ISA should not have cold extremities because the dmg produces minimal decreases in peripheral blood flow (smaller increases in resistance). In addition, these agents should produce minimal depression of heart rate and cardiac output, either at rest or during exercise (36). 

P-Adrenoceptor blockers for the treatment of hypertension include (/) the cardioselective P -adrenoceptor blockers without intrinsic sympathomimetic activity (ISA), ie, atenolol (Table 3), bisoprolol (Table 3), and metoprolol (Table 1) (2) the cardioselective with ISA, ie, acebutolol (Table 1) (J) the noncardioselective without ISA, ie, propranolol (Table 1) and timolol [26839-75-8] C23H24N4O2S and (4) the noncardioselective with ISA, ie, oxprenolol [6452-71-7] C 3H23N03, and pindolol. 

Acutrim 16 Hour Steady Control Tablets. Acuttim is an appetite suppressant diet aid available without a prescription and marketed by CIBA Consumer Pharmaceuticals. The active ingredient is phenylpropanolamine hydrochloride [154-41 -6] a sympathomimetic amine (see Antiobesity drugs). Acutrim dehvers its dosage at a precisely controlled rate for up to 16 hours. This is achieved through the OROS technology. 

Sympathomimetics with free amino groups e g carbadrine, norfenefnne, noradrenaline, norephednne... 

Polyethylene glycol primary amines, indole derivatives, sympathomimetics stabilization and enhancement dipping solution, 20% in methanol [270]... 

As already stated, the number of substances made by chemists for pharmacological examination as possible sympathomimetic amines is enormous and the literature voluminous. Fortunately the latter has been reviewed from time to time, and most recently in the symposium in which Hartung dealt with the correlation of structure and pharmacological action in )3-phenylethylamine derivatives, which includes the more impor-... 

Omission of the side chain hydroxyl group from molecules based on epinephrine or ephedrine does not abolish the sympathomimetic activity of the resulting compounds. Many of these agents exert a considerable stimulant action on the central nervous system. As such, drugs in this class have been widely used—and... 

Sympathomimetic. A drug that produces effects similar to stimulating the sympathetic nervous system, that is, increased blood pressure, dilated bronchi, and mydriasis. 

Amphetamine and related compounds are indirect acting sympathomimetic agents that are frequently abused due to their stimulant properties on the central nervous system. Amphetamines act by inducing the... 

The appetite-suppressing effect of (3-phenylethylamine drugs is either related to their sympathomimetic effect (metamphetamine, phentermine, diethylpropion), to... 

Hypertensive reaction resulting from release of noradrenaline by tyramine and other sympathomimetic amine as a consequence of irreversible inhibition of MAO-A. 

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