Pectus
Pectus 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.
Guaifenesin possesses a storied history, having been originally formally approved by the US FDA in 1952 and continues to be one of very few - if not perhaps the only drug that is readily available and used as an expectorant . Since that time the agent has been a combination component of various prescription and non-prescription over-the-counter cough and cold products and is currently a widely available over-the-counter generic medication . Although it is principally believed that guaifenesin elicits an action to facilitate productive cough to manage chest congestion , it is not known whether the agent can reliably mitigate coughing.
Regardless, on March 1, 2007, the FDA received a petition asking the FDA to notify the public that some antitussives, expectorants, decongestants, antihistamines, and cough/cold combinations are not known to be safe and effective in children under the age of 6 years . After the negotiation between FDA and major manufacturers, a voluntary transition of labels for not using guaifenesin in children under the age of 4 years was endorsed by FDA in 2008 .
Furthermore, there has also been contemporary research to suggest that guaifenesin possesses and is capable of demonstrating anticonvulsant and muscle relaxant effects to some degree possibly by acting as an NMDA receptor antagonist .
| Trade Name | Pectus |
| Generic | Chlorpheniramine (Maleate) + Dextromethorphan + Guaifenesin + Phenylpropanolamine (HCl) + Sodium Acid Citrate |
| Weight | 3.75mg/5ml, 10mg/5ml, 100mg/5ml, 6mg/5ml, 150mg/5ml |
| Type | Syrup |
| Therapeutic Class | |
| Manufacturer | Tabros Pharma |
| 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.
Guaifenesin is an expectorant commonly found in OTC products for the symptomatic relief from congested chests and coughs associated with cold, bronchitis, and/or other breathing illnesses.
Guaifenesin is an expectorant that is indicated for providing temporary symptomatic relief from congested chests and coughs which may be due to a cold, bronchitis, and/or other breathing illnesses .
Pectus 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 Reaction, Asthma, Asthma, Allergic, Bronchial Asthma, Bronchitis, Bronchospasm, Chronic Bronchitis, Chronic Obstructive Respiratory Diseases, Common Cold, Cough, Cough caused by Common Cold, Coughing caused by Allergies, Coughing caused by Flu caused by Influenza, Drug Allergy, Emphysema, Fever, Flu caused by Influenza, Food Allergy, Headache, House dust allergy, Irritative cough, Laryngitis, Nasal Congestion, Nasal Congestion caused by Common Cold, Phlegm, Pollen Allergy, Productive cough, Rash, Rhinorrhoea, Sneezing, Sore Throat, Tracheitis, Urticaria, Whooping Cough, Acute Rhinitis, Chest congestion, Chills occurring with fever, Dry cough, Excess mucus or phlegm, Mild to moderate pain, Minor aches and pains, Airway secretion clearance therapy, Expectorant
How Pectus 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.
Although the exact mechanism of action of guaifenesin may not yet be formally or totally elucidated, it is believed that expectorants like guaifenesin function by increasing mucus secretion . Moreover, it is also further proposed that such expectorants may also act as an irritant to gastric vagal receptors, and recruit efferent parasympathetic reflexes that can elicit glandular exocytosis that is comprised of a less viscous mucus mixture . Subsequently, these actions may provoke coughing that can ultimately flush difficult to access, congealed mucopurulent material from obstructed small airways to facilitate a temporary improvement for the individual .
Consequently, while it is generally proposed that guaifenesin functions as an expectorant by helping to loosen phlegm (mucus) and thin bronchial secretions to rid the bronchial passageways of bothersome mucus and make coughs more productive, there has also been research to suggest that guaifenesin possesses and is capable of demonstrating anticonvulsant and muscle relaxant effects to some degree possibly by acting as an NMDA receptor antagonist .
Dosage
Pectus 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.
The most prevalent signs and symptoms associated with an overdose of guaifenesin have been nausea and vomiting .
Although adequate and well-controlled studies in pregnant women have not been performed, the Collaborative Perinatal Project monitored 197 mother-child pairs exposed to guaifenesin during the first trimester . An increased occurrence of inguinal hernias was found in the neonates . However, congenital defects were not strongly associated with guaifenesin use during pregnancy in 2 large groups of mother-child pairs .
Moreover, guaifenesin is excreted in breast milk in small quantities . Subsequently, caution should be exercised by balancing the potential benefit of treatment against any possible risks .
Additionally, an LD50 value of 1510 mg/kg (rat, oral) has been reported for guaifenesin .
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.
The geometric mean apparent volume of distribution of guaifenesin determined in healthy adult subjects is 116L (CV=45.7%) .
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.
Studies have shown that guaifenesin is well absorbed from and along the gastrointestinal tract after oral administration .
Half Life
Dextromethorphan has a half life of 3-30 hours.
The half-life in plasma observed for guaifenesin is approximately one hour .
Clearance
The mean clearance recorded for guaifenesin is about 94.8 L/hr (CV=51.4%) .
Elimination Route
After administration, guaifenesin is metabolized and then largely excreted in the urine .
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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