No clinically significant interaction have been reported.
It is important to note that P450 inducers, such as
Rifampicin or valproate, may induce the metabolism of montelukast

Bambuterol may prolong the muscle relaxing effect of suxamethonium

Co-administration of bambuterol with beta-blockers inhibits the effect of betablockers

Prophylaxis and chronic treatment of asthma.

Rash
Dyspepsia, dizziness, abdominal pain
Nasal congestion, tonic muscle cramps

Palpitations, hypersensitivity reactions

Irritability restlessness, insomnia,
Vomiting, diarrhea

Rarely systemic eosinophillia, sometimes patients may present clinical features of vasculitis with
Chung-Strauss syndrome.

Urticaria and exanthema, sleep and behavoiural changes may be observed

Hypersensitivity

Special precautions:
Montelukast is not indicated for the use in the reversal of bronchospasm in acute asthma attacks
 including status asthmatics

Bambuterol should be used with caution in patients with hyperthyroidism and diabetes. These drugs
have arrythmia potential hence must be considered in the treatment of individual patients

Indications:
Prophylaxis and chronic treatment of asthma.

Dosage:
Adult- (>14 years)  10mg daily at bed time

Children- (6- 14 years)  5mg daily at bed time.

Pharmacology:
Montelukast is a selective reversible leukotriene receptor antagonist. It binds with high affinity to the
 LD4 receptor inhibiting bronchoconstriction. Bambuterol a prodrug of the adrenergic beta-receptor
 agonist terbutaline,  predominantly stimulates B2 receptors, and produces relaxation of bronchial
smooth muscle, inhibition of the release of endogenous spasmogens, inhibition of edema caused
by endogenous mediatiors and increased mucociliary clearance.

Pharmacokinetics:
Montelkast is rapidly absorbed following oral administration reaching peak levels at 2 to 2.5 hrs  
after administration of the 5mg tablet and 2 to 4 hrs after administration of the 10mg tablet.
The bioavailability of 10mg tablet is approx 64% regardless of whether it is adminisatered with food.
 Montelukast is 100% protein bound. It undergoes extensive metabolism in the liver by the cytochrome
P450 enzyme system, especially CYP3A4 and CYP2C9, and is excreted into the bile.
 The mean plasma half-life of the drug is 2.7 to 5.5 hrs.  

About 20% of an oral dose of bambuterol is absorbed. The absorption is not influenced by
 concomittant intake of food.
The protein binding of bambuterol is low. At therapeutic concentrations, overall plasma protein
 binding is approx 40 to 50%. After absorption, bambuterol is slowly metabolised via hydrolysis
(plasma cholinesterase) and oxidation to active terbutaline. About 1/3 of the absorbed dose is
metabolised in the intestinal walls and in the liver, mainly to intermediary metabolites.  About 10%
of the administerd drug is converted to tebutaline in adults. The plasma half-life
of bambuterol  after oral administration is about 9- 17 hrs. Bambuterol and its metabolites including
terbutaline are mainly excreted via the kidneys.

Rationale for the combination:
The combination of an oral bronchodilator and an anti-inflammatory agent would take care of both the
 components of asthma, bronchoconstriction and inflammation, which give greater clinical efficacy.
 This product has an advantage as administration by the oral route, which will aid compliance and be
of benefit in patients with poor inhaler technique.



 

The bioavailability is unaffected regardless whether it is administered with food or not.

Montelukast is known to be excreted into breast milk, but only limited information is avialable on the significance of this finding.

Caution should be used prior to initiating therapy during pregnancy and lactation.