Crotamiton¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Crotamiton relieves itching by producing what is called a counter-irritation. As crotamiton evaporates from the skin, it produces a cooling effect. This cooling effect helps to divert your body's attention away from the itching. 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
Crotamiton¿¡ ´ëÇÑ Pharmacology Á¤º¸ Crotamiton is usually used to treat pruritis (itching of the skin) caused by scabies or sunburn. Crotamiton relieves itching by producing what is called a counter-irritation. As crotamiton evaporates from the skin, it produces a cooling effect. This cooling effect helps to divert your body's attention away from the itching. Due to this cooling effect it is also effective for the relief of sunburn. The drug is also believed to kill scabies through an unknown mechanism. 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.
Crotamiton¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ Not Available Dibucaine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ Not Available Diphenhydramine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ 98 to 99%
Half-life
Crotamiton¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ Not Available Dibucaine¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ Not Available Diphenhydramine¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ 1-4 hours
Absorption
Crotamiton¿¡ ´ëÇÑ Absorption Á¤º¸ 10 % absorbed when applied locally. 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.
Crotamiton¿¡ ´ëÇÑ Biotransformation Á¤º¸ Not Available Dibucaine¿¡ ´ëÇÑ Biotransformation Á¤º¸ Primarily hepatic. Diphenhydramine¿¡ ´ëÇÑ Biotransformation Á¤º¸ Hepatic and renal
Toxicity
Crotamiton¿¡ ´ëÇÑ Toxicity Á¤º¸ Not Available 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
Crotamiton¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Acetohexamide The beta-blocker decreases the symptoms of hypoglycemiaChlorpropamide The beta-blocker decreases the symptoms of hypoglycemiaCimetidine Cimetidine increases the effect of the beta-blockerClonidine Increased hypertension when clonidine stoppedDisopyramide The beta-blocker increases toxicity of disopyramideGliclazide The beta-blocker decreases the symptoms of hypoglycemiaGlipizide The beta-blocker decreases the symptoms of hypoglycemiaGlisoxepide The beta-blocker decreases the symptoms of hypoglycemiaGlibenclamide The beta-blocker decreases the symptoms of hypoglycemiaGlycodiazine The beta-blocker decreases the symptoms of hypoglycemiaInsulin The beta-blocker decreases the symptoms of hypoglycemiaLidocaine The beta-blocker increases the effect and toxicity of lidocainePropafenone Propafenone increases the effect of beta-blockerRepaglinide The beta-blocker decreases the symptoms of hypoglycemiaRifampin Rifampin decreases the effect of the metabolized beta-blockerTelithromycin Telithromycin may possibly increase metoprolol effectTolazamide The beta-blocker decreases the symptoms of hypoglycemiaTolbutamide The beta-blocker decreases the symptoms of hypoglycemiaAmobarbital The barbiturate decreases the effect of metabolized beta-blockerAprobarbital The barbiturate decreases the effect of metabolized beta-blockerButalbital The barbiturate decreases the effect of metabolized beta-blockerButabarbital The barbiturate decreases the effect of metabolized beta-blockerButethal The barbiturate decreases the effect of metabolized beta-blockerDihydroquinidine barbiturate The barbiturate decreases the effect of metabolized beta-blockerHeptabarbital The barbiturate decreases the effect of metabolized beta-blockerHexobarbital The barbiturate decreases the effect of metabolized beta-blockerMethohexital The barbiturate decreases the effect of metabolized beta-blockerMethylphenobarbital The barbiturate decreases the effect of metabolized beta-blockerPentobarbital The barbiturate decreases the effect of metabolized beta-blockerPhenobarbital The barbiturate decreases the effect of metabolized beta-blockerPrimidone The barbiturate decreases the effect of metabolized beta-blockerQuinidine barbiturate The barbiturate decreases the effect of metabolized beta-blockerSecobarbital The barbiturate decreases the effect of metabolized beta-blockerTalbutal The barbiturate decreases the effect of metabolized beta-blockerCitalopram The SSRI increases the effect of the beta-blockerEscitalopram The SSRI increases the effect of the beta-blockerFluoxetine The SSRI increases the effect of the beta-blockerSertraline The SSRI increases the effect of the beta-blockerParoxetine The SSRI increases the effect of the beta-blockerDihydroergotamine Ischemia with risk of gangreneDihydroergotoxine Ischemia with risk of gangreneErgonovine Ischemia with risk of gangreneErgotamine Ischemia with risk of gangreneMethysergide Ischemia with risk of gangreneVerapamil Increased effect of both drugsHydralazine Increased effect of both drugsDiltiazem Increased risk of bradycardiaEpinephrine Hypertension, then bradycardiaFenoterol AntagonismFormoterol AntagonismIsoproterenol AntagonismOrciprenaline AntagonismPirbuterol AntagonismPrazosin Risk of hypotension at the beginning of therapyProcaterol AntagonismSalbutamol AntagonismSalmeterol AntagonismTerbutaline AntagonismIbuprofen Risk of inhibition of renal prostaglandinsIndomethacin Risk of inhibition of renal prostaglandinsPiroxicam Risk of inhibition of renal prostaglandins 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
Crotamiton¿¡ ´ëÇÑ Description Á¤º¸ Crotamiton is a scabicidal and antipruritic agent available as a cream or lotion for topical use only. It is a colorless to slightly yellowish oil, having a faint amine-like odor. It is miscible with alcohol and with methanol. 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.