Brand Name : KOFTAB
Generic Name : Bromhexine HCl 8 mg + Phenylephrine HCl 10 mg + Chlorpheniramine Maleate 4 mg
Preparation : Tablet
Pharmacological Category : Cough Expectorant

Mechanism of Action (MOA)

  • Bromhexine HCl depolymerizes mucopolysachharide directly as well as by liberating lysosomal enzymes, hence breaks network of fibers in tenacious sputum. Thus, viscosity of bronchial secretion is reduced facilitating its removal by coughing.
  • Phenylephrine HCl is a selective α1 agonist. It constricts the nasal blood vessels, thereby decreasing blood flow to the sinusoidal vessels, leading to decreased mucosal edema.
  • Chlorpheniramine maleate selectively and competitively blocks the binding of histamine to its H1 receptors. Further, it has low anticholinergic action and mild sedative effects. Thus, it blocks histamine induced allergic reactions and bronchoconstriction thereby providing relief in cough.

Pharmacokinetics
Bromhexine HCl :

  • Absorption : Rapidly absorbed from the gastrointestinal tract
  • Peak Plasma Concentration : About 1 hour
  • Bioavailability : About 20%
  • Distribution : Widely distributed to body tissues, crosses the blood-brain barrier and small amounts cross the placenta
  • Metabolism : Liver
  • Elimination Half-life : 13 to 14 hours
  • Excretion : 85 to 90% via urine

Phenylephrine HCl :

  • Absorption : Completely absorbed from the gastrointestinal tract
  • Bioavailability : Approximately 38%
  • Peak Plasma Concentration : 0.75 to 2 hours
  • Onset of Action : 15 to 20 minutes (nasal decongestion)
  • Duration : 2 to 4 hours
  • Distribution : Peripheral tissues, brain (minimal)
  • Metabolism : Extensively metabolised in the intestinal wall; moderately in liver
  • Elimination Half-life : 2 to 3 hours
  • Excretion : Urine (80 to 86%)

Chlorpheniramine maleate :

  • Absorption : Absorbed relatively slowly from the gastrointestinal tract
  • Peak Plasma Concentration : About 2.5 to 6 hours
  • Bioavailability : 25 to 50%
  • Protein Binding : 70%
  • Duration of Action : 4 to 6 hours
  • Distribution : Widely distributed and enters the central nervous system
  • Metabolism : Metabolized predominantly in the liver, but also in the lungs and kidneys
  • Elimination : Urine (primarily)

Indications and Dosage

  • Respiratory Disorder associated with Productive Cough : One tablet of KOFTAB 3 or 4 times daily, maximum 6 tablets daily; avoid use in children less than 12 years of age

Side Effects
Nausea, vomiting, diarrhoea, epigastric pain, headache, dizziness, skin rashes, anorexia, weakness, dyspnea, anxiety, fear, restlessness, insomnia, confusion, irritability, lassitude, incoordination, dry mouth, blurred vision, urinary difficulty, constipation, palpitation, tachycardia, arrhythmias

Contraindications
Hypersensitivity to bromhexine hydrochloride, phenylephrine hydrochloride and chlorpheniramine maleate, asthma, nursing women, sleep apnea, severe hypertension, ventricular tachycardia, closed-angle glaucoma, hyperthyroidism, prostatic hyperplasia

Warnings / Precautions

  • Caution in patient with a history of peptic ulcer as bromhexine may disrupt the gastric mucosal barrier.
  • Caution in patient with asthma, severe ischemic heart disease, angle-closure glaucoma, urinary retention, prostatic hyperplasia, or pyloroduodenal obstruction, epilepsy.
  • Clearance of bromhexine or its metabolites may be reduced in patients with severe hepatic and renal impairment.
  • Do not drive, operate machine due to drowsiness or dizziness.

Drug Interactions

  • Chlorpheniramine maleate may enhance the sedative effects of CNS depressants including alcohol, barbiturates, hypnotics, opioid analgesics, anxiolytic sedatives and antipsychotics.
  • Chlorpheniramine maleate has an additive antimuscarinic action with other antimuscarinic drugs such as atropine and some antidepressants (both tricyclics and MAOIs).
  • Chlorpheniramine maleate may mask the symptoms of ototoxicity with ototoxic medications.
  • Agents that may potentiate pressure effect of phenylephrine are α2 agonists, β blockers, tricyclic antidepressants, corticosteroids, Atropine and norepinephrine reuptake inhibitors.
  • Agents that may reduce the pressure effect of phenylephrine are benzodiazepines and phosphodiesterase.
  • General anaesthetics can have risk of increased cardiac irritability and arrhythmias when given with phenylephrine.
  • Antihypertensive agents may antagonize effects of phenylephrine.
  • Digoxin may sensitize the myocardium to the effects of phenylephrine.
  • Diuretics may reduce the response to phenylephrine.
  • Excessive rise in BP may occur when phenylephrine is used with ergot alkaloids.
  • Phosphodiesterase (PDE) type 5 inhibitors may reduce the pressor effect of phenylephrine.

Pregnancy Category : C

Presentation
KOFTAB : A box of 30 blisters, each blister of 10 tablets