Dextil

Uses

Indicated mainly in allergic conditions including urticaria, sensitivity reactions, angioneurotic oedema, seasonal hay fever, vasomotor rhinitis, cough, common cold, motion sickness.

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 .

Phenylpropanolamine is a sympathomimetic that was previously used in nasal decongestants and weight loss products, but has been withdrawn by the FDA due to safety risks and lack of efficacy.

For the treatment of nasal congestion, control of urinary incontinence, priapism and obesity.

Dextil is also used to associated treatment for these conditions: Allergic Contact Dermatitis, Allergic Reaction, Allergic Rhinitis (AR), Allergic cough, Allergies, Allergies caused by Serum, Allergy to House Dust, Allergy to vaccine, Angioneurotic Edema, Asthma, Bronchial Asthma, Bronchitis, Common Cold, Conjunctival congestion, Conjunctivitis, Conjunctivitis allergic, Cough, Cough caused by Common Cold, Coughing caused by Flu caused by Influenza, Drug Allergy, Eye allergy, Fever, Flu caused by Influenza, Food Allergy, Headache, Headache caused by Allergies, Itching of the nose, Itching of the throat, Migraine, Nasal Congestion, Nasal Congestion caused by Common Cold, Pollen Allergy, Productive cough, Pruritus, Rash, Rhinorrhoea, Seasonal Allergic Conjunctivitis, Sinus Congestion, Sinusitis, Sneezing, Transfusion Reactions, Upper Respiratory Tract Infection, Upper respiratory tract hypersensitivity reaction, site unspecified, Urticaria, Vasomotor Rhinitis, Acute Rhinitis, Allergic purpura, Conjunctival hyperemia, Dry cough, Excess mucus or phlegm, Itchy throat, Mild bacterial upper respiratory tract infections, Ocular hyperemia, Throat inflammation, Upper airway congestion, Upper respiratory symptoms, Watery eyes, Watery itchy eyes, Airway secretion clearance therapyAllergic 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, ExpectorantAllergy-Induced Respiratory Symptoms, Bronchitis, Common Cold, Cough, Nasal Congestion, Rhinorrhoea, Excess mucus or phlegm

How Dextil works

Chlorpheniramine 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.

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 .

Phenylpropanolamine acts directly on alpha- and, to a lesser degree, beta-adrenergic receptors in the mucosa of the respiratory tract. Stimulation of alpha-adrenergic receptors produces vasoconstriction, reduces tissue hyperemia, edema, and nasal congestion, and increases nasal airway patency. PPA indirectly stimulates beta-receptors, producing tachycardia and a positive inotropic effect.

Dosage

Dextil dosage

Adults: 4 mg 3-4 times daily.

Children:

• Up to 1( one) year: 1 mg twice daily
• 1-5 years: 1 mg 3-4 times daily
• 6-12 years: 2 mg 3-4 times daily or as directed by the physician

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

Drowsiness, dizziness, headache, psychomotor impairment, urinary retention, dry mouth, blurred vision and gastro intestinal disturbances, paradoxical stimulation may rarely occur, especially in high dosage or in children.

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

Oral LD50 (rat): 306 mg/kg; Oral LD50 (mice): 130 mg/kg; Oral LD50 (guinea pig): 198 mg/kg [Registry of Toxic Effects of Chemical Substances. Ed. D. Sweet, US Dept. of Health & Human Services: Cincinatti, 2010.] Also a mild reproductive toxin to women of childbearing age.

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 .

May induce ventricular extrasystoles and short paroxysms of ventricular tachycardia, a sensation of fullness in the head and tingling of the extremities; LD₅₀=1490mg/kg (orally in rat)

Precaution

Chlorpheniramine may produce mild sedation and it is advised that patients under continuous treatment should avoid operating machinery. Not recommended during pregnancy & lactation.

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

Alcohol, CNS depressants, anticholinergic drugs, MAOIs.

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

Well absorbed in the gastrointestinal tract.

A 30mg oral dose of dextromethorphan reaches a C_max of 2.9 ng/mL, with a T_max 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 .

Reduced bioavailability (about 38%) from gastrointestinal tract because of first pass metabolism by monoamine oxidase in the stomach and liver.

Half Life

21-27 hours

Dextromethorphan has a half life of 3-30 hours.

The half-life in plasma observed for guaifenesin is approximately one hour .

2.1 to 3.4 hours.

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 Category B. Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).

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

There is no definite contraindication to therapy. It should be used with caution in epilepsy, prostatic hypertrophy, glaucoma and hepatic disease. The ability to drive or operate machinery may be impaired.

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

Innovators Monograph

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