Dextromethorphan¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Dextromethorphan is an opioid-like drug that binds to and acts as antagonist to the NMDA glutamatergic receptor, it is an agonist to the opioid sigma 1 and sigma 2 receptors, it is also an alpha3/beta4 nicotinic receptor antagonist and targets the serotonin reuptake pump. Dextromethorphan is rapidly absorbed from the gastrointestinal tract, where it enters the bloodstream and crosses the blood-brain barrier. The first-pass through the hepatic portal vein results in some of the drug being metabolized into an active metabolite of dextromethorphan, dextrorphan, the 3-hydroxy derivative of dextromethorphan. Pseudoephedrine¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Pseudoephedrine acts directly on both alpha- and, to a lesser degree, beta-adrenergic receptors. Through direct action on alpha-adrenergic receptors in the mucosa of the respiratory tract, pseudoephedrine produces vasoconstriction. Pseudoephedrine relaxes bronchial smooth muscle by stimulating beta2-adrenergic receptors. Like ephedrine, pseudoephedrine releasing norepinephrine from its storage sites, an indirect effect. Triprolidine¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Triprolidine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.
Pharmacology
Dextromethorphan¿¡ ´ëÇÑ Pharmacology Á¤º¸ Dextromethorphan suppresses the cough reflex by a direct action on the cough center in the medulla of the brain. Dextromethorphan shows high affinity binding to several regions of the brain, including the medullary cough center. This compound is an NMDA receptor antagonist and acts as a non-competitive channel blocker. It is one of the widely used antitussives, and is also used to study the involvement of glutamate receptors in neurotoxicity. Pseudoephedrine¿¡ ´ëÇÑ Pharmacology Á¤º¸ Pseudoephedrine is a sympathomimetic agent, structurally similar to ephedrine, used to relieve nasal and sinus congestion and reduce air-travel-related otalgia in adults. The salts pseudoephedrine hydrochloride and pseudoephedrine sulfate are found in many over-the-counter preparations either as single-ingredient preparations, or more commonly in combination with antihistamines and/or paracetamol/ibuprofen. Unlike antihistamines, which modify the systemic histamine-mediated allergic response, pseudoephedrine only serves to relieve nasal congestion commonly associated with colds or allergies. The advantage of oral pseudoephedrine over topical nasal preparations, such as oxymetazoline, is that it does not cause rebound congestion (rhinitis medicamentosa). Triprolidine¿¡ ´ëÇÑ Pharmacology Á¤º¸ In allergic reactions an allergen interacts with and cross-links surface IgE antibodies on mast cells and basophils. Once the mast cell-antibody-antigen complex is formed, a complex series of events occurs that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H1-receptors, produces pruritis, vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Triprolidine, is a histamine H1 antagonist that competes with histamine for the normal H1-receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies.
Metabolism
Dextromethorphan¿¡ ´ëÇÑ Metabolism Á¤º¸ # Phase_1_Metabolizing_Enzyme:Cytochrome P450 2D6 (CYP2D6) Pseudoephedrine¿¡ ´ëÇÑ Metabolism Á¤º¸ # Phase_1_Metabolizing_Enzyme:Monoamine oxidase type A (MAO-A) Triprolidine¿¡ ´ëÇÑ Metabolism Á¤º¸ # Phase_1_Metabolizing_Enzyme:Not Available
Protein Binding
Pseudoephedrine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ Pseudoephedrine does not bind to human plasma proteins over the concentration range of 50 to 2000 ng/mL Triprolidine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ Not Available
Dextromethorphan¿¡ ´ëÇÑ Absorption Á¤º¸ Rapidly absorbed from the gastrointestinal tract. Pseudoephedrine¿¡ ´ëÇÑ Absorption Á¤º¸ Pseudoephedrine is readily and almost completely absorbed from the GI tract and there is no evidence of first-pass metabolism. Triprolidine¿¡ ´ëÇÑ Absorption Á¤º¸ Rapidly absorbed in the intestinal tract.
Biotransformation
Dextromethorphan¿¡ ´ëÇÑ Biotransformation Á¤º¸ Hepatic. Rapidly and extensively metabolized to dextrorphan (active metabolite). One well known metabolic catalyst involved is a specific cytochrome P450 enzyme known as 2D6, or CYP2D6. Pseudoephedrine¿¡ ´ëÇÑ Biotransformation Á¤º¸ Hepatic. Triprolidine¿¡ ´ëÇÑ Biotransformation Á¤º¸ Not Available
Toxicity
Dextromethorphan¿¡ ´ëÇÑ Toxicity Á¤º¸ Not Available Pseudoephedrine¿¡ ´ëÇÑ Toxicity Á¤º¸ Common adverse reactions include nervousness, restlessness, and insomnia. Rare adverse reactions include difficult/painful urination, dizziness/lightheadedness, heart palpitations, headache, increased sweating, nausea/vomiting, trembling, troubled breathing, unusual paleness, and weakness. Triprolidine¿¡ ´ëÇÑ Toxicity Á¤º¸ Symptoms of overdose include drowsiness, weakness, inco-ordination, difficulty with micturition, respiratory depression, hypotension, agitation, irritability, convulsions, hypertension, palpitation and tachycardia.
Drug Interactions
Dextromethorphan¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Dihydroquinidine barbiturate Quinidine increases the toxicity of dextromethorphanQuinidine Quinidine increases the toxicity of dextromethorphanQuinidine barbiturate Quinidine increases the toxicity of dextromethorphanFluoxetine Combination associated with possible serotoninergic syndromeIsocarboxazid Possible severe adverse reactionMemantine Increased risk of CNS adverse effectsMoclobemide Increased CNS toxicityParoxetine Combination associated with possible serotoninergic syndromePhenelzine Possible severe adverse reactionRasagiline Possible severe adverse reactionSelegiline Combination associated with possible serotoninergic syndromeSibutramine Combination associated with possible serotoninergic syndromeTerbinafine Terbinafine increases dextromethorphan levelsTranylcypromine Possible severe adverse reaction Pseudoephedrine¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Alseroxylon Increased arterial pressureIsocarboxazid Increased arterial pressureLinezolid Possible increase of arterial pressureMethyldopa Increased arterial pressureBromocriptine The sympathomimetic increases the toxicity of bromocriptineTranylcypromine Increased arterial pressureMidodrine Increased arterial pressureMoclobemide Moclobemide increases the sympathomimetic effectPargyline Increased arterial pressurePhenelzine Increased arterial pressureRasagiline Increased arterial pressureReserpine Increased arterial pressureTrimipramine The tricyclic increases the sympathomimetic effectProtriptyline The tricyclic increases the sympathomimetic effectNortriptyline The tricyclic increases the sympathomimetic effectAmitriptyline The tricyclic increases the sympathomimetic effectAmoxapine The tricyclic increases the sympathomimetic effectClomipramine The tricyclic increases the sympathomimetic effectImipramine The tricyclic increases the sympathomimetic effectDesipramine The tricyclic increases the sympathomimetic effectDoxepin The tricyclic increases the sympathomimetic effectDeserpidine Increased arterial pressureGuanethidine The agent decreases the effect of guanethidine Triprolidine¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Not Available
Dextromethorphan¿¡ ´ëÇÑ Description Á¤º¸ The d-isomer of the codeine analog of levorphanol. Dextromethorphan shows high affinity binding to several regions of the brain, including the medullary cough center. This compound is an NMDA receptor antagonist (receptors, N-methyl-D-aspartate) and acts as a non-competitive channel blocker. It is one of the widely used antitussives, and is also used to study the involvement of glutamate receptors in neurotoxicity. [PubChem] Pseudoephedrine¿¡ ´ëÇÑ Description Á¤º¸ An alpha- and beta-adrenergic agonist that may also enhance release of norepinephrine. It has been used in the treatment of several disorders including asthma, heart failure, rhinitis, and urinary incontinence, and for its central nervous system stimulatory effects in the treatment of narcolepsy and depression. It has become less extensively used with the advent of more selective agonists. [PubChem] Triprolidine¿¡ ´ëÇÑ Description Á¤º¸ Histamine H1 antagonist used in allergic rhinitis; asthma; and urticaria. It is a component of cough and COLD medicines. It may cause drowsiness. [PubChem]