sympathomimetic drugs

agents that mimic the sympathetic nervous system, acting at alpha- or beta-adrenergic receptors within target tissues; vasoconstrictor sympathomimetics raise blood pressure by acting on alpha-adrenergic receptors, causing central vasoconstriction; beta receptor-active sympathomimetics dilate bronchi and peripheral blood vessels; beta-blockers block beta-receptor sites and promote peripheral vasoconstriction; adrenaline is a sympathomimetic drug that acts on both alpha- and beta-adrenergic receptors and is used to counter symptoms of anaphylaxis (it both raises blood pressure and dilates bronchi) Table 1

**Table 1:** Effects of stimulation of alpha, beta and dopamine receptors
Receptor	Action	Stimulating drug
Alpha-1 (α₁); postsynaptic	Vasoconstriction; positive inotropism; antidiuresis	Adrenaline + Noradrenaline +++
Alpha-2 (α₂); presynaptic	Vasodilatation; inhibition of noradrenaline release	Adrenaline + Noradrenaline +++ Dopamine +
Alpha-2 (α₂); postsynaptic	Constriction of coronary arteries; promotion of salt and water excretion	Adrenaline + Noradrenaline +++ Dopamine +
Beta-1 (β₁); postsynaptic	Positive inotropism; chronotropism; renin release	Adrenaline ++ Noradrenaline ++ Isoprenaline ++ Dopamine +
Beta-2 (β₂); presynaptic	Noradrenaline release accelerated; positive inotropism; chronotropism	Adrenaline + Isoprenaline +++
Beta-2 (β₂); postsynaptic	Vasodilatation; relaxation of bronchial smooth muscle	Adrenaline + Isoprenaline +++
Dopamine₁; postsynaptic	Vasodilatation; diuresis	Dopamine ++
Dopamine₁; presynaptic	Inhibits noradrenaline release	Dopamine +
Plus signs indicate degree of effect.

sympathomimetic drugs

Drugs that produce an effect similar to that obtained by stimulation of the sympathetic nervous system. Some of these predominantly act on the adrenergic alpha-receptors (e.g. noradrenaline (norepinephrine)), while others act on the adrenergic beta-receptors (e.g. isoproterenol). Others have little direct effect on the adrenergic receptors but enhance the release of natural catecholamine from the sympathetic nerve terminals (e.g. amphetamine, phenylpropanolamine). Sympathomimetic drugs are used (1) in the treatment of open-angle glaucoma by decreasing aqueous humour secretion and increase the outflow through the trabecular meshwork thus reducing the intraocular pressure (e.g. adrenaline (epinephrine), apraclonidine, dipivefrine hydrochloride, brimonidine tartrate), (2) dilate the pupil without affecting accommodation (e.g. phenylephrine) and (3) constrict conjunctival blood vessels (e.g. naphazoline, tetrahydrozoline). Syn. adrenergic agonist; adrenergic stimulating agent. See alpha-adrenergic agonist; mydriatic.

References in periodicals archive ?

Intracavernosal treatment * Injection of sympathomimetic drugs (phenylephrine) 4.

Priapism: a case study and review

Hypertension may result from use of illicit drugs, oral contraceptives, herbal supplements, nonsteroidal anti-inflammatory medications, some psychiatric medications, steroids, or sympathomimetic drugs like diet pills or decongestants (Vera & Neutze, 2010).

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For instance, sympathomimetic drugs can lead to rapid increase in blood pressure, arrhythmias, myocardial infarction and heart failure,particularly in elderly patients with coronary artery disease.

EVALUATING EFFECTIVENESS OF WARMING ENDOTRACHEAL TUBE IN BLIND NASOTRACHEAL INTUBATION IN MAXILLOFACIAL SURGERY

Catecholamines, sympathomimetic drugs and adrenergic receptors antagonists.

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Several classes of drugs including topical mydriatics anticolinergics antidepressants anticonvulsants antihistaminics sulphamate derivative adrenergics and sympathomimetic drugs have the capacity to actuate an acute attack of angle closure.

Do we really need to panic in all acute vision loss in ICU Acute angle-closure glaucoma

VENTRICULAR PREMATURE COMPLEXES [VPC]: VPC's are often the commonly seen arrhythmias during the peri-operative period and can be caused by cardiac and non-cardiac factors like electrolyte imbalances, hypoxia, hypercarbia, anesthetic agents, tobacco, caffeine, alcohol, sympathomimetic drugs and antidepressant drugs.

Perioperative cardiac arrhythmias: an approach

Summary: TEHRAN (FNA)- Researchers at Payam-e-Noor University of Tehran in collaboration with experts from Tabriz University of Medical Sciences found a simple synthesis method for zinc oxide (and hydroxide) and their application in modified carbon paste electrodes for determination of sympathomimetic drugs at micro-molar scales.

Zinc Oxide, Hydroxide Nanoparticles Utilized in Detecting Drugs

Administration of sympathomimetic drugs is the most effective method for maintaining blood pressure and tissue perfusion during anesthesia in horses.

Influence of acepromazine on the cardiovascular actions of dobutamine in isoflurane-anesthetized horses/Influencia da acepromazina sobre os efeitos cardiovasculares da dobutamina em cavalos anestesiados com isofluorano

Sympathomimetic drugs, including cocaine and amphetamines, are commonly associated with intracranial hemorrhage, possibly due to transient hypertension or arteritis-like vascular change.

The face of hillbilly heroin and other images of narcotic abuse

Amphetamine (R,S-1-phenyl-2-propanamine) and methamphetamine (R,S -N-methyl-1 -phenyl-2-propanamine) are powerful stimulants that affect the central nervous system by acting as indirect sympathomimetic drugs (Kraemer & Maurer 2002).

Effects of methamphetamine abuse beyond individual users

Amphetamines are non-catecholamine indirect sympathomimetic drugs that structurally resemble noradrenaline (2).

Drug abuse and dependency during pregnancy: anaesthetic issues

Dental professionals should use caution when administering other sympathomimetic drugs (e.