Dextromethorphan And Quinidine
Dextromethorphan And Quinidine 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.
An optical isomer of quinine, extracted from the bark of the Cinchona tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular action potential, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.
Quinidine, a hydantoin anticonvulsant, is used alone or with phenobarbital or other anticonvulsants to manage tonic-clonic seizures, psychomotor seizures, neuropathic pain syndromes including diabetic neuropathy, digitalis-induced cardiac arrhythmias, and cardiac arrhythmias associated with QT-interval prolongation.
| Trade Name | Dextromethorphan And Quinidine |
| Generic | Dextromethorphan + quinidine |
| Weight | 20mg + 10mg |
| Type | Oral capsule |
| Therapeutic Class | |
| Manufacturer | |
| Available Country | United States |
| 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.
Quinidine is a medication used to restore normal sinus rhythm, treat atrial fibrillation and flutter, and treat ventricular arrhythmias.
For the treatment of ventricular pre-excitation and cardiac dysrhythmias
Dextromethorphan And Quinidine 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 antisepsisAtrial Fibrillation or Flutter, Malaria caused by Plasmodium falciparum, Pseudobulbar affect, Arrhythmia of ventricular origin
How Dextromethorphan And Quinidine 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.
Quinidine acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers. Quinidine may also act on the slow inward calcium current (ICa), the rapid (IKr) and slow (IKs) components of the delayed potassium rectifier current, the inward potassium rectifier current (IKI), the ATP-sensitive potassium channel (IKATP) and Ito.
Dosage
Dextromethorphan And Quinidine 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.
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.
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.
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).
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.
- 2 to 3 L/kg
- 0.5 L/kg [congestive heart failure]
- 3 to 5 L/kg [cirrhosis of the liver]
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.
Half Life
Dextromethorphan has a half life of 3-30 hours.
6-8 hours
Clearance
- 3 – 5 mL/min/kg [adults]
Elimination Route
When the urine pH is less than 7, about 20% of administered quinidine appears unchanged in the urine, but this fraction drops to as little as 5% when the urine is more alkaline.
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.
Contraindication
Hypersensitivity to Dextromethorphan or any other component.
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.
Storage Condition
Store at 15-30° C
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