Dibucaine¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Local anesthetics block both the initiation and conduction of nerve impulses by decreasing the neuronal membrane's permeability to sodium ions. This reversibly stabilizes the membrane and inhibits depolarization, resulting in the failure of a propagated action potential and subsequent conduction blockade. Diphenhydramine¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Diphenhydramine competes with free histamine for binding at HA-receptor sites. This antagonizes the effects of histamine on HA-receptors, leading to a reduction of the negative symptoms brought on by histamine HA-receptor binding.
Pharmacology
Dibucaine¿¡ ´ëÇÑ Pharmacology Á¤º¸ Dibucaine is an amide-type local anesthetic, similar to lidocaine. Diphenhydramine¿¡ ´ëÇÑ Pharmacology Á¤º¸ Diphenhydramine is an antihistamine of the ethanolamine class. Ethanolamine antihistamines have significant antimuscarinic activity and produce marked sedation in most patients. In addition to the usual allergic symptoms, the drug also treats irritant cough and nausea, vomiting, and vertigo associated with motion sickness. It also is used commonly to treat drug-induced extrapyramidal symptoms as well as to treat mild cases of Parkinson's disease. Rather than preventing the release of histamine, as do cromolyn and nedocromil, diphenhydramine competes with free histamine for binding at HA-receptor sites. Diphenhydramine competitively antagonizes the effects of histamine on HA-receptors in the GI tract, uterus, large blood vessels, and bronchial muscle. Ethanolamine derivatives have greater anticholinergic activity than do other antihistamines, which probably accounts for the antidyskinetic action of diphenhydramine. This anticholinergic action appears to be due to a central antimuscarinic effect, which also may be responsible for its antiemetic effects, although the exact mechanism is unknown.
Dibucaine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ Not Available Diphenhydramine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ 98 to 99%
Half-life
Dibucaine¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ Not Available Diphenhydramine¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ 1-4 hours
Absorption
Dibucaine¿¡ ´ëÇÑ Absorption Á¤º¸ In general, ionized forms (salts) of local anesthetics are not readily absorbed through intact skin. However, both nonionized (bases) and ionized forms of local anesthetics are readily absorbed through traumatized or abraded skin into the systemic circulation. Diphenhydramine¿¡ ´ëÇÑ Absorption Á¤º¸ Quickly absorbed with maximum activity occurring in approximately one hour.
Dibucaine¿¡ ´ëÇÑ Toxicity Á¤º¸ Subcutaneous LD50 in rat is 27 mg/kg. Symptoms of overdose include convulsions, hypoxia, acidosis, bradycardia, arrhythmias and cardiac arrest. Diphenhydramine¿¡ ´ëÇÑ Toxicity Á¤º¸ LD50=500 mg/kg (orally in rats). Considerable overdosage can lead to myocardial infarction (heart attack), serious ventricular dysrhythmias, coma and death.
Drug Interactions
Dibucaine¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Methotrexate The NSAID increases the effect and toxicity of methotrexateLithium The NSAID increases serum levels of lithiumAcenocoumarol The NSAID increases the anticoagulant effect Diphenhydramine¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Atomoxetine The CYP2D6 inhibitor could increases the effect and toxicity of atomoxetineDonepezil Possible antagonism of actionGalantamine Possible antagonism of actionMesoridazine Increased risk of cardiotoxicity and arrhythmiasRivastigmine Possible antagonism of actionThioridazine Increased risk of cardiotoxicity and arrhythmias
Dibucaine¿¡ ´ëÇÑ Description Á¤º¸ A local anesthetic of the amide type now generally used for surface anesthesia. It is one of the most potent and toxic of the long-acting local anesthetics and its parenteral use is restricted to spinal anesthesia. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1006) Diphenhydramine¿¡ ´ëÇÑ Description Á¤º¸ A histamine H1 antagonist used as an antiemetic, antitussive, for dermatoses and pruritus, for hypersensitivity reactions, as a hypnotic, an antiparkinson, and as an ingredient in common cold preparations. It has some undesired antimuscarinic and sedative effects.
Drug Category
Dibucaine¿¡ ´ëÇÑ Drug_Category Á¤º¸ Anesthetics, Local Diphenhydramine¿¡ ´ëÇÑ Drug_Category Á¤º¸ AnestheticsAnesthetics, LocalAnti-Allergic AgentsAntidyskineticsAntiemeticsAntiparkinson AgentsAntipruriticsAntitussivesEthanolamine DerivativesHistamine H1 AntagonistsHypnotics and Sedatives