Corex-d
Corex-d Uses, Dosage, Side Effects, Food Interaction and all others data.
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.
Dextromethorphan is an opioid-like molecule indicated in combination with other medication in the treatment of coughs and pseudobulbar affect. It has a moderate therapeutic window, as intoxication can occur at higher doses. Dextromethorphan has a moderate duration of action. Patients should be counselled regarding the risk of intoxication.
Pseudoephedrine is both an α-and β-adrenergic receptor agonist. It causes vasoconstriction via direct stimulation of α-adrenergic receptors of the respiratory mucosa. It also directly stimulates β-adrenergic receptors causing bronchial relaxation, increased heart rate and contractility.
Like ephedrine, pseudoephedrine releasing norepinephrine from its storage sites, an indirect effect. This is its main and direct mechanism of action. The displaced noradrenaline is released into the neuronal synapse where it is free to activate the postsynaptic adrenergic receptors.
Ephedrine is a sympathomimetic amine that activates adrenergic receptors, increasing heart rate and blood pressure, and causing bronchodilation. The therapeutic window is wide as patients can be given doses of 5mg up to 50mg. Patients should be counselled regarding the pressor effects of sympathomimetic amines and the risk of tachyphylaxis.
Sodium citrate is the sodium salt of citric acid. It is white, crystalline powder or white, granular crystals, slightly deliquescent in moist air, freely soluble in water,practically insoluble in alcohol. Like citric acid, it has a sour taste.From the medical point of view, it is used as alkalinizing agent. It works by neutralizing excess acid in the blood and urine. It has been indicated for the treatment of metabolic acidosis.
Citrate prevents activation of the clotting cascade by chelating calcium ions. Citrate neutralizes acid in the stomach and urine, raising the pH .
Trade Name | Corex-d |
Generic | Chlorpheniramine (Maleate) + Dextromethorphan + Ephedrine + Sodium Citrate |
Weight | 4mg/5ml, 10mg/5ml, 5mg/5ml, 150mg/5ml |
Type | Syrup |
Therapeutic Class | |
Manufacturer | Pfizer Laboratories Ltd, |
Available Country | Pakistan |
Last Updated: | September 19, 2023 at 7:00 am |
Uses
Dextromethorphan is used for Chronic dry cough or unproductive cough; Acute dry cough which is interfering with normal function or sleep.
Pseudoephedrine is a decongestant of the mucous membranes of the upper respiratory tract, especially the nasal mucosa, sinuses and eustachian tube. It is used for the symptomatic relief of allergic rhinitis (hay fever), vasomotor rhinitis, the common cold, influenza (flu) and ear congestion caused by ear inflammation or infection. Pseudoephedrine can also be used as a bronchodilator.
Pseudoephedrine is a stereoisomer of Ephedrine with similar but less potent pharmacological activity. It has nasal and bronchial decongestant activity.
Sodium citrate is an ingredient used for the anticoagulation of whole blood as part of automated apheresis procedures.
Used as an anticoagulant during plasmophoresis as well as a neutralizing agent in the treatment of upset stomach and acidic urine .
Corex-d is also used to associated treatment for these conditions: Allergic cough, Common Cold, Common Cold/Flu, Cough, Cough caused by Common Cold, Coughing caused by Allergies, Coughing caused by Bronchitis, Coughing caused by Flu caused by Influenza, Fever, Flu caused by Influenza, Headache, Irritative cough, Itching of the nose, Itching of the throat, Nasal Congestion, Pseudobulbar affect, Rhinorrhoea, Sneezing, Upper respiratory symptoms, Watery itchy eyes, Airway secretion clearance therapy, Bronchodilation, Oropharyngeal antisepsisAllergic Disorder, Bronchial Asthma, Common Cold, Cough, Depression, Fever, General Anesthesia Induced Hypotension, Headache, Joint Pain, Myasthenia Gravis, Narcolepsy, Nasal Congestion, Rhinorrhoea, Sore Throat, Dry coughAcidosis, Allergic cough, Allergies, Asthma, Asthma Chronic, Cough, Common Cold, Cough, Coughing caused by Bronchitis, Dehydration, Gouty Arthritis, Heartburn, Metabolic Acidosis, Phlegm, Airway secretion clearance therapy, Oral rehydration therapy, Plasmapheresis, Urine alkalinization therapy, Fluid and electrolyte maintenance therapy, Irrigation during surgical procedures, Irrigation of the ocular surface therapy
How Corex-d works
Dextromethorphan is an agonist of NMDA and sigma-1 receptors. It is also an antagonist of α3/β4 nicotinic receptors.[A10589] However, the mechanism by which dextromethorphan's receptor agonism and antagonism translates to a clinical effect is not well understood.
Ephedrine is a direct and indirect sympathomimetic amine. Ephedrine activates adrenergic α and β-receptors as well as inhibiting norepinephrine reuptake, and increasing the release of norepinephrine from vesicles in nerve cells. These actions combined lead to larger quantities of norepinephrine present in the synapse, for longer periods of time, increasing stimulation of the sympathetic nervous system. Ephedrine's stimulation of α-1 receptors causes constriction of veins and a rise in blood pressure, stimulation of β-1 adrenergic receptors increase cardiac chronotropy and inotropy, stimulation of β-2 adrenergic receptors causes bronchodilation.
Citrate chelates free calcium ions preventing them from forming a complex with tissue factor and coagulation factor VIIa to promote the activation of coagulation factor X . This inhibits the extrinsic initiation of the coagulation cascade. Citrate may also exert an anticoagulant effect via a so far unknown mechanism as restoration of calcium concentration does not fully reverse the effect of citrate . Citrate is a weak base and so reacts with hydrochloric acid in the stomach to raise the pH. It it further metabolized to bicarbonate which then acts as a systemic alkalizing agent, raising the pH of the blood and urine . It also acts as a diuretic and increases the urinary excretion of calcium.
Dosage
Corex-d dosage
Adults and Children over 12 years: 15 to 30 mg three to four times per day. However, 60 mg doses up to four times per day have been used without increased side effects.
Children between 6 and 12 years: 5-15 mg up to four times per day.
Children between 2 and 6 years: 2.5-5 mg up to four times per day.
As a decongestant and symptomatic treatment for upper respiratory tract infections the recommended dose is:
Adults: 1 tablet every 4 to 6 hours, up to maximum of 240 mg in 24 hours
Children:
- 6-12 years of age: 1/2 tablet every 4 to 6 hours daily
- 2-5 years of age: 1/4 tablet every 4 to 6 hours daily
- Less than 2 years of age: This drug is not advised unless specifically recommended by a physician.
Side Effects
Adverse effects with Dextromethorphan are rare, but nausea and dizziness sometimes occur. The drug produces no analgesia or addiction and little or no CNS depression. Excitation, confusion and respiratory depression may occur after overdosage.
Serious adverse effects associated with the use of Pseudoephedrine are rare. Symptoms of central nervous system excitation may occur, including sleep disturbances and, rarely, hallucinations have been reported. Skin rashes, with or without irritation, have occasionally been reported.
Toxicity
A dextromethorphan overdose may present as nausea, vomiting, stupor, coma, respiratory depression, seizures, tachycardia, hyperexcitability, toxic psychosis, ataxia, nystagmus, dystonia, blurred vision, changes in muscle reflexes, and serotonin syndrome. Overdose should be managed through symptomatic and supportive measures.
Patients experiencing an overdose of ephedrine will present with rapidly increasing blood pressure. Manage overdose with blood pressure monitoring, and possibly the administration of parenteral antihypertensives. The LD50 in mice after oral administration is 785mg/kg, after intraperitoneal administration if 248mg/kg, and after subcutaneous administration is 425mg/kg.
Overdose toxicity is mainly due to alkalosis as well as tetany or depressed heart function due to lack of free calcium .
Precaution
Do not use Dextromethorphan to control a cough that is associated with smoking, asthma, or emphysema, or a cough that is productive (produces sputum or phlegm).
Although Pseudoephedrine has virtually no pressor effects in normotensive patients, it should be used with caution in patients suffering mild to moderate hypertension. As with other sympathomimetic agents, Pseudoephedrine should be used with caution in patients with hypertension, heart disease, diabetes, hyperthyroidism, elevated intraocular pressure and prostatic enlargement. Caution should be exercised when using the product in the presence of severe hepatic impairment or moderate to severe renal impairment.
Interaction
The following medicines should be taken carefully while concomitantly use with Dextromethorphan: Amiodarone, Fluoexetine, Quinidine, CNS depressants and Monoamine oxidase (MAO) inhibitors.
Volume of Distribution
The volume of distribution of dextromethorphan is 5-6.7L/kg.
Oral ephedrine has an average volume of distribution of 215.6L.
19-39L .
Elimination Route
A 30mg oral dose of dextromethorphan reaches a Cmax of 2.9 ng/mL, with a Tmax of 2.86 h, and an AUC of 17.8 ng*h/mL.
Oral ephedrine reaches an average Cmax of 79.5ng/mL, with a Tmax of 1.81h, and a bioavailability of 88%.
Tmax of 98-130min .
Half Life
Dextromethorphan has a half life of 3-30 hours.
Oral ephedrine has a plasma elimination half life of approximately 6 hours, but there is a large degree of inter-patient variability.
18-54 min
Clearance
Oral ephedrine has a clearance of 23.3L/h but there is a high degree of inter-patient variability.
Total clearance of 313-1107mL/min .
Elimination Route
Ephedrine is mainly eliminated in the urine. Approximately 60% is eliminated as the unmetabolized parent compound, 13% as benzoic acid conjugates, and 1% as 1,2-dihydroxypropylbenzene.
Largely eliminated through hepatic metabolism with very little cleared by the kidneys .
Pregnancy & Breastfeeding use
Pregnancy: Adequate and well-controlled studies in human have not been done. However, Dextromethorphan has not been reported to cause birth defects.
Lactation: It is not known whether dextromethorphan passes into breast milk. However, Dextromethorphan has not been reported to cause problems in nursing babies.
Although Pseudoephedrine has been in widespread use for many years without apparent ill consequence, there are no specific data on its use during pregnancy. Caution should therefore be exercised by balancing the potential benefit of treatment to the mother against any possible hazards to the developing foetus. Pseudoephedrine is excreted in breast milk in small amounts but the effect of this on breast-fed infants is not known.
Contraindication
Hypersensitivity to Dextromethorphan or any other component.
Pseudoephedrine is contraindicated in-
- Hypersensitivity of individuals to this drug
- Severe hypertension and coronary artery disease
- Concurrent use of Mono Amine Oxidase Inhibitor (MAOI) drugs
Acute Overdose
Symptoms: In mild overdose, tachycardia, hypertension, vomiting, mydriasis, diaphoresis, nystagmus, euphoria, loss of motor coordination, and giggling; in moderate intoxication, in addition to those listed above, hallucinations and a plodding ataxic gait; in severely intoxication, agitation or somnolence.
Management: treatment is symptomatic and supportive. Naloxone may be useful in reversing toxicity.
As with other sympathomimetic agents, symptoms of overdosage include irritability, restlessness, tremor, convulsions, palpitations, hypertension and difficulty in micturition. Necessary measures should be taken to maintain and support respiration and control convulsions. Gastric lavage should be performed if indicated. If desired, the elimination of Pseudoephedrine can be accelerated by acid diuresis or by dialysis.
Storage Condition
Store at 15-30° C
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