sympathomimetic agents

WordNet

1. a substance that exerts some force or effect
2. a businessman who buys or sells for another in exchange for a commission (同)factor, broker
3. any agent or representative of a federal agency or bureau (同)federal agent
4. a representative who acts on behalf of other persons or organizations
5. an active and efficient cause; capable of producing a certain effect; "their research uncovered new disease agents"

PrepTutorEJDIC

1. 『代理人』;周旋人 / 働き(作用)を起こすもの;作用物,薬剤 / (政府機関,特にFBI,CIAなどの)部員,機関員

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/11/23 22:55:47」(JST)

wiki en

[Wiki en表示]

Epinephrine

Norepinephrine

Dopamine

Chemical structures of catecholamines.

Sympathomimetic drugs are stimulant compounds which mimic the effects of agonists of the sympathetic nervous system such as the catecholamines. (epinephrine (adrenaline), norepinephrine (noradrenaline), dopamine, etc.) Sympathomimetic drugs are used to treat cardiac arrest and low blood pressure, or even delay premature labor, among other things.

These drugs can act through several mechanisms, such as directly activating postsynaptic receptors, blocking breakdown and reuptake of certain neurotransmitters, or stimulating production and release of catecholamines.

Mechanisms of action

The mechanisms of sympathomimetic drugs can be direct-acting, such as α-adrenergic agonists, β-adrenergic agonists, and dopaminergic agonists; or indirect-acting, such as MAOIs, COMT inhibitors, release stimulants, and reuptake inhibitors that increase the levels of endogenous catecholamines.

Structure-activity relationship

For maximum sympathomimetic activity, a drug must have:

1. Amine group two carbons away from an aromatic group
2. A hydroxyl group at the chiral beta position in the R-configuration
3. Hydroxyl groups in the meta and para position of the aromatic ring to form a catechol which is essential for receptor binding

The structure can be modified to alter binding. If the amine is primary or secondary, it will have direct action, but if the amine is tertiary, it will have poor direct action. Also, if the amine has bulky substituents, then it will have greater beta adrenergic receptor activity, but if the substituent is not bulky, then it will favor the alpha adrenergic receptors.

Direct-acting

Adrenergic receptor agonists

Main article: Adrenergic agonist

Direct stimulation of the α- and β-adrenergic receptors can produce sympathomimetic effects. Salbutamol is a very commonly used direct-acting β₂-agonist. Other examples include phenylephrine, isoproterenol, and dobutamine.

Dopaminergic agonists

Stimulation of the D1 receptor by dopaminergic agonists such as fenoldopam is used intravenously to treat hypertensive crisis.

Indirect-acting

Norepinephrine and dopamine transporter blockade

Classic examples of indirect sympathomimetic drugs are amphetamines (including MDMA), ephedrine, and cocaine, which act by blocking and reversing norepinephrine transporter (NET) activity. NET is a transport protein expressed on the surface of some cells that clears noradrenaline and adrenaline from the extracellular space and into cells, terminating the signaling

Structure-activity relationship

A primary or secondary aliphatic amine separated by 2 carbons from a substituted benzene ring is minimally required for high agonist activity. The pKa of the amine is approximately 8.5-10. 1- Substitution on aromatic ring-

The presence of hydroxy group in the benzene ring at 3rd and 4th position shows maximum alpha and beta activity

Cross-reactivity

Substances such as cocaine also affect dopamine, and some substances such as MDMA affect serotonin.

Norepinephrine is synthesized by the body from the amino acid tyrosine, and is used in the synthesis of epinephrine, which is a stimulating neurotransmitter of the central nervous system. Thus, all sympathomimetic amines fall into the larger group of stimulants (see psychoactive drug chart). In addition to intended therapeutic use, many of these stimulants have abuse potential, can induce tolerance, and possibly physical dependence, although not by the same mechanism(s) as opioids or sedatives. The symptoms of physical withdrawal from stimulants can include fatigue, dysphoric mood, increased appetite, vivid or lucid dreams, hypersomnia or insomnia, increased movement or decreased movement, anxiety, and drug craving, as is apparent in the rebound withdrawal from certain substituted amphetamines. Physical withdrawal from some sedatives can be potentially lethal, for instance benzodiazepine withdrawal syndrome. Opioid withdrawal is very uncomfortable, often described as a bad case of the flu, with possibly severe abdominal cramps and diarrhoea as central symptoms, but it is rarely lethal unless the user has a comorbid condition.

Comparison

"Parasympatholytic" and "sympathomimetic" are similar, but not identical. For example, both cause mydriasis, but parasympatholytics reduce accommodation (cycloplegia) while sympathomimetics do not.

Examples

• amphetamine (Benzedrine)
• benzylpiperazine (BZP)
• cathine (found in Catha edulis)
• cathinone (found in Catha edulis, khat)
• cocaine (found in Erythroxylum coca, coca)
• ephedrine (found in Ephedra)
• lisdexamfetamine (Vyvanse)
• maprotiline (Ludiomil)
• MDMA (Ecstasy, Molly)
• methamphetamine (Meth, Crank, Desoxyn)
• methcathinone
• methylenedioxypyrovalerone (MDPV)
• methylphenidate (Ritalin)
• 4-methylaminorex
• oxymetazoline (Afrin, Vicks Sinex)
• pemoline (Cylert)
• phenmetrazine (Preludin)
• propylhexedrine (Benzedrex)
• pseudoephedrine (Sudafed, SudoGest, also found in Ephedra species)

See also

• Sympathetic nervous system

References

External links

• Amines, Sympathomimetic at the US National Library of Medicine Medical Subject Headings (MeSH)

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 起立性低血圧および食後低血圧の治療 treatment of orthostatic and postprandial hypotension
• 2. 喘息または再発性喘鳴を有する小児に対する麻酔 anesthesia for the child with asthma or recurrent wheezing
• 3. 慢性閉塞性肺疾患（COPD）治療における粘膜作用剤の役割 role of mucoactive agents in the treatment of copd
• 4. Anesthesia for the older adult
• 5. 慢性閉塞性肺疾患患者に対する麻酔 anesthesia for patients with chronic obstructive pulmonary disease

English Journal

• Antenatal exposure to sulindac and risk of necrotizing enterocolitis.

• Kamath-Rayne BD1, Habli M2, Rodriguez Z3, Wu M4, Gresh J4, DeFranco EA5.
• American journal of obstetrics and gynecology.Am J Obstet Gynecol.2015 Jan;212(1):96.e1-7. doi: 10.1016/j.ajog.2014.07.051. Epub 2014 Aug 1.
• OBJECTIVE: Most studies of tocolytics are underpowered to assess drug effects on rare adverse neonatal outcomes. Our aim was to optimize statistical power to assess the influence of sulindac on the rare but severe outcome of necrotizing enterocolitis (NEC) by performing a case-control study.STUDY DE
• PMID 25088864

• A new strategy to prevent chemotherapy and radiotherapy-induced alopecia using topically applied vasoconstrictor.

• Soref CM1, Fahl WE.
• International journal of cancer. Journal international du cancer.Int J Cancer.2015 Jan 1;136(1):195-203. doi: 10.1002/ijc.28961. Epub 2014 May 16.
• In a new strategy, we sought to determine whether topically applied vasoconstrictor, with its accompanying transient skin hypoxia and exclusion of systemic drug, would prevent or suppress radiotherapy or chemotherapy-induced alopecia. Topical vasoconstrictor was applied to 1-cm(2) skin patches on th
• PMID 24811525

Japanese Journal

• 症例検討カンファレンス形式の静脈麻酔教育

• 日本臨床麻酔学会誌 36(1), 79-82, 2016
• NAID 130005125754

• 構造からみた胎児付属物の異常とその臨床

• 日本産科婦人科學會雜誌 54(8), 1170-1175, 2002-08-01
• NAID 110002185427

• A Case of Aortic Dissection With Transient ST-Segment Elevation due to Functional Left Main Coronary Artery Obstruction

• Japanese circulation journal 64(2), 130-134, 2000-01-20
• NAID 110002572768

Related Links

• Sympathomimetic | definition of sympathomimetic by Medical ...

sympathomimetic [sim″pah-tho-mi-met´ik] 1. producing effects resembling those of impulses transmitted by the postganglionic fibers of the sympathetic nervous system. See also adrenergic. 2. an agent that produces such an effect.

• Sympathomimetic Agents (Parenteral-Systemic)

Side/Adverse Effects Note: Peripheral vasoconstriction, possibly leading to necrosis or gangrene, may occur with prolonged use of sympathomimetic agents with alpha-1 adrenergic agonist activity in high doses or low doses in the ...

---

★リンクテーブル★

関連記事	「agent」「sympathomimetic」

「agent」

　　[★]

• n.

• 代行者、代理人。代理業者
• 政府職員、官吏
• ある後位をする人、ある作用をするもの。動員、動力因、作用因。(文法)動作主。科学的変化を起こさせるもの、薬品、～剤。病原体

関

agonist、agonistic、attorney、delegate、drug、etiologic agent、fomes、fomites、mediator、pathogen、pathogenic、pharmaceutical preparation、vector、vehicle

　 　 　 　 　 　

「sympathomimetic」

　　[★]

mimetic

• adj.

• 交感神経興奮性の

• n.

• 交感神経興奮剤、交感神経作動薬

関

sympathomimetic agent、sympathomimetic amine、sympathomimetic drug