Labetalol

Gefahreninformationscode (GHS)

• Bildanzeige (GHS)

  

• Alarmwort

  Warnung

• Gefahrenhinweise

  H315：Verursacht Hautreizungen.

  H319：Verursacht schwere Augenreizung.

  H335：Kann die Atemwege reizen.

  H361：Kann vermutlich die Fruchtbarkeit beeinträchtigen oder das Kind im Mutterleib schädigen.

  H411：Giftig für Wasserorganismen, mit langfristiger Wirkung.

• Sicherheit

  P201：Vor Gebrauch besondere Anweisungen einholen.

  P202：Vor Gebrauch alle Sicherheitshinweise lesen und verstehen.

  P264：Nach Gebrauch gründlich waschen.

  P264：Nach Gebrauch gründlich waschen.

  P280：Schutzhandschuhe/Schutzkleidung/Augenschutz tragen.

  P281：Vorgeschriebene persönliche Schutzausrüstung verwenden.

  P302+P352：BEI BERÜHRUNG MIT DER HAUT: Mit viel Wasser/... (Hersteller kann, falls zweckmäßig, ein Reinigungsmittel angeben oder, wenn Wasser eindeutig ungeeignet ist, ein alternatives Mittel empfehlen) waschen.

  P305+P351+P338：BEI KONTAKT MIT DEN AUGEN: Einige Minuten lang behutsam mit Wasser spülen. Eventuell vorhandene Kontaktlinsen nach Möglichkeit entfernen. Weiter spülen.

  P308+P313：BEI Exposition oder falls betroffen: Ärztlichen Rat einholen/ärztliche Hilfe hinzuziehen.

  P321：Besondere Behandlung

  P332+P313：Bei Hautreizung: Ärztlichen Rat einholen/ärztliche Hilfe hinzuziehen.

  P362：Kontaminierte Kleidung ausziehen und vor erneutem Tragen waschen.

  P405：Unter Verschluss aufbewahren.

  P501：Inhalt/Behälter ... (Entsorgungsvorschriften vom Hersteller anzugeben) zuführen.

Labetalol Chemische Eigenschaften,Einsatz,Produktion Methoden

• Beschreibung

  Labetalol is an α-adrenergic and α-1 blocking agent which caused contact dermatitis and a contact anaphylactoid reaction during patch testing in a nurse.

• Originator

  Trandate,Allen and Hanburys,UK,1977

• Verwenden

  Labetalol is used to treat essential hypertension.

• Verwenden

  Anti-adrenergic (α-receptor); anti-adrenergic (β-receptor).

• Definition

  ChEBI: A secondary amino compound formally derived from ammonia by replacing two of the hydrogens by 2-(3-carbamoyl-4-hydroxyphenyl)-2-hydroxyethyl and 4-phenylbutan-2-yl groups. It is an adrenergic antagonist used to treat high blood pressure.

• Manufacturing Process

  (a) 5-Bromoacetylsalicylamide (2.6 g), N-benzyl-N-(1-methyl-3-phenylpropyl) amine (4.8 g) and methyl ethyl ketone (50 ml) were heated at reflux for 40 minutes. The solvent was removed and the residue was treated with benzene. The secondary amine hydrobromide was filtered off and discarded, and the filtrate was evaporated to dryness. The residue was treated with an excess of ethanolic hydrogen chloride when 5-[N-benzyl-N-(1-methyl-3-phenylpropyl)- glycyl]-salicylamide hydrochloride (1.15 g) crystallized out, MP 139°C to 141°C.
  (b) 5-[N-benzyl-N-(1-methyl-3-phenylpropyl)glycyl]-salicylamide hydrochloride (0.75 g), 10% mixture of PdO and PtO on carbon catalyst (0.1 g) and ethanol (20 ml) were shaken at room temperature and pressure with hydrogen until uptake ceased. The catalyst was filtered off and the filtrate evaporated to dryness. The residue was crystallized from ethanol to give 5-[1- hydroxy-2-(1-methyl-3-phenylpropyl)aminoethyl]salicylamide hydrochloride as a white solid (0.40 g), MP 188°C.

• Trademarks

  Normodyne (Schering); Trandate (Promethus).

• Therapeutic Function

  Alpha-adrenergic blocker, Beta-adrenergic blocker

• Biologische Funktion

  Labetalol (Normodyne, Trandate) possesses both - blocking and β-blocking activity and is approximately one-third as potent as propranolol as a -blocker and one-tenth as potent as phentolamine as an -blocker. The ratio of β- to α-activity is about 3:1 when labetalol is administered orally and about 7: 1 when it is administered intravenously. Thus the drug can be most conveniently thought of as a β -blocker with some -blocking properties.

• Allgemeine Beschreibung

  Labetalol is a phenylethanolamine derivative, is representative of a classof drugs that act as competitive blockers at α1-, β1-, andβ2-receptors. It is a more potent β-blocker than α-blocker.Because it has two asymmetric carbon atoms (1 and 1' ), it existsas a mixture of four isomers. It is this mixture that is usedclinically in treating hypertension. The different isomers,however, possess different α- and β-blocking activities. The -blocking activity resides solely in the (1R,1 'R) isomer,whereas the 1-blocking activity is seen in the (1S,1 R) and(1S,1'S) isomers, with the (1S,1'R) isomer possessing thegreater therapeutic activity.

• Kontakt-Allergie

  This beta-adrenergic and alpha-1 blocking agent caused contact dermatitis and a contact anaphylactoid reaction during patch testing in a nurse.

• Mechanism of action

  Labetalol produces equilibrium-competitive antagonism at β-receptors but does not exhibit selectivity for β1- or β2-receptors. Like certain other β-blockers (e.g., pindolol and timolol), labetalol possesses some degree of intrinsic activity. This intrinsic activity, or partial agonism, especially at β2-receptors in the vasculature, has been suggested to contribute to the vasodilator effect of the drug. The membrane-stabilizing effect, or local anesthetic action, of propranolol and several other β-blockers, is also possessed by labetalol, and in fact the drug is a reasonably potent local anesthetic.
  Labetalol appears to produce relaxation of vascular smooth muscle not only by α-blockade but also by a partial agonist effect at β2-receptors. In addition, labetalol may produce vascular relaxation by a direct non–receptor-mediated effect. Labetalol can block the neuronal uptake of norepinephrine and other catecholamines. This action, plus its slight intrinsic activity at α-receptors, may account for the seemingly paradoxical, although infrequent, increase in blood pressure seen on its initial administration.

• Pharmakokinetik

  Labetalol is almost completely absorbed from the gastrointestinal tract. However, it is subject to considerable first-pass metabolism, which occurs in both the gastrointestinal tract and the liver, so that only about 25% of an administered dose reaches the systemic circulation. While traces of unchanged labetalol are recovered in the urine, most of the drug is metabolized to inactive glucuronide conjugates.The plasma half-life of labetalol is 6 to 8 hours, and the elimination kinetics are essentially unchanged in patients with impaired renal failure.

• Clinical Use

  Labetalol is a clinically usefulantihypertensive agent. The rationale for its use in themanagement of hypertension is that its α-receptor–blockingeffects produce vasodilation and its β-receptor–blockingeffects prevent the reflex tachycardia usually associated withvasodilation. Although labetalol is very well absorbed, it undergoesextensive first-pass metabolism.

• Nebenwirkungen

  There have been reports of excessive hypotension and paradoxical pressor effects following intravenous administration of labetalol. These latter effects may be due to a labetalol-induced blockade of neuronal amine uptake, which increases the concentrations of norepinephrine in the vicinity of its receptors.
  Approximately 5% of the patients who receive labetalol complain of side effects typical of noradrenergic nervous system suppression. These include postural hypotension, gastrointestinal distress, tiredness, sexual dysfunction, and tingling of the scalp. Most of these effects are related to α-blockade, although the tingling of the scalp may be due to the drug’s intrinsic activity at α-receptors. Side effects associated with β-blockade, such as induction of bronchospasm and congestive heart failure, may also occur, but generally at a lower frequency than -receptor–associated effects.
  Skin rashes have been reported, as has an increase in the titer of antinuclear antibodies. Despite the latter observation, the appearance of a systemic lupus syndrome is rare. Labetalol also has been reported to interfere with chemical measurements of catecholamines and metabolites.

• Synthese

  Labetalol, 2-hydroxy-5-[1-hydroxy-2-[(1-methyl-3-phenylpropanol)amino)] ethyl] benzamide (12.1.12) is synthesized by the N-alkylation of N-benzyl-N(4-phenyl-2- butyl)amine 5-bromacetylsalicylamide and forming aminoketone (12.1.11), which is further debenzylated by hydrogen using a palladium¨Cplatinum on carbon catalyst into labetalol (12.1.12) [28¨C30].

  

Labetalol Upstream-Materialien And Downstream Produkte

Labetalol Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

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