Pharmacology for Dentistry

232 Section 5/ Autacoids

rotransmitter of the adrenergic nervous sys-
tem. They also protect effectively against the
challenge with various bronchoconstrictor
agents and may inhibit microvascular leak-
age into the airway. β 2 -agonists are the drug
of choice to relieve acute exacerbation of
asthma and prevent bronchoconstriction
following exercise or other stimuli. After
inhalation the β2-agonists have rapid onset
of action (within minutes), but are active
only for 4 to 6 hours.

Their adverse effects are dose-related
and are more common after oral than aero-
sol administration because of the manifold
higher dose required for oral drugs. Some
of the important β 2 -agonists like salmeterol,

terbutaline and salbutamol are invariably

used as bronchodilators both oral as well as

aerosol inhalants. Salmeterol is long-acting

analogue of salbutamol in which the amine

substituent is a long lipophilic chain, but

found to be slower in achieving the peak

bronchodilatation effect. The detailed phar-

macology is discussed in chapter ‘Adrener-

gic Agents’.

Specific agents used in bronchial asth-

ma are discussed here.

SALBUTAMOL

It is highly selective β 2 -adrenergic stim-

ulant having a prominent bronchodilator

action. It has poor cardiac action compared

Table 5.4.2: Classification for antiasthmatic drugs.

I. Bronchodilators

i. Sympathomimetics (adrenergic receptor agonists)

Adrenaline, ephedrine, isoprenaline, orciprenaline, salbutamol, terbutaline, salmeterol, bambuterol

etc.

ii. Methylxanthines (theophylline and its derivatives)

Theophylline (THEOLONG) 200-400 mg TDS

Hydroxyethyl theophylline (DERIPHYLLIN) 250-500 mg/day oral/IM/IV

Theophylline ethanolate of piperazine (CADIPHYLLATE) 250-500 mg/day oral/IV

iii. Anticholinergics

Atropine methonitrate (BROVON INHALANT) 2.5-10 mg/day oral/IM, 1-2 mg (aerosol)

Ipratropium bromide (IPRATOP) 40-80 μg day (aerosol)

II. Mast cell stabilizer

Sodium cromoglycate (CHROMOTOP) 2 mg by aerosol TDS-QID, 2% nasal

spray (FINTAL)

Ketotifen (AIRYFEN) 1-2 mg/day

III.Corticosteroids

Beclomethasone dipropionate (BACLATE INHALER) 100-200 μg TDS-QID

Beclomethasone (200 μg) with salbutamol (AEROCORT

ROTACAPS) 2 rotacaps TDS-QID

IV.Leukotriene pathway inhibitors (newer compounds)

Montelukast (MONTAIR) 10 mg HS

Zafirlukast (ACCOLATE) 20 mg/day