RESPIRATORY SYSTEM
PHARMACOLOGY
Dr Nasim Ullah Siddiqui
DRUGS USED TO TREAT ALLERGIC
RHINITIS
Rhinitis is an inflammation of the mucous
membranes of the nose and is characterized by
sneezing, itchy nose/eyes, watery rhinorrhea,
and nasal congestion.
An attack may be precipitated by inhalation of
an allergen (such as dust, pollen, or animal
dander).
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
The foreign material interacts with mast cells
coated with IgE generated in response to a
previous allergen expo-sure .
The mast cells release mediators, such as
histamine, leukotrienes, and chemotactic
factors, that promote bronchiolar spasm and
mucosal thickening from edema and cellular
infiltration.
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
Combinations of oral antihistamines with
decongestants are the first-line therapies for
allergic rhinitis.
Systemic effects associated with these oral
preparations (sedation, insomnia, and, rarely,
cardiac arrhythmias) have prompted interest in
topical intranasal delivery of drugs.
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
Antihistamines (H1-receptor blockers)
Antihistamines are the most frequently used agents in
the treatment of sneezing and watery rhinorrhea
associated with allergic rhinitis.
H1-histamine
receptor
blockers,
such
as
diphenhydramine, chlorpheniramine , loratadine , and
fexofenadine, are useful in treating the symptoms of
allergic rhinitis caused by histamine release.
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
Ocular and nasal antihistamine delivery devices
are available over-the-counter for more targeted
tissue delivery.
Combinations
of
antihistamines
with
decongestants are effective when congestion is
a feature of rhinitis.
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
Antihistamines differ in their ability to cause
sedation and in their duration of action.
In general, anticholinergic side effects of the
first-generation antihistamines (dry eyes/mouth,
difficulty urinating and/or defecating) are
transient and may resolve in 7 to 10 days.
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
α-Adrenergic agonists
Short-acting α-adrenergic agonists (“nasal
decongestants”), such as phenylephrine,
constrict dilated arterioles in the nasal mucosa
and reduce airway resistance.
Longer-acting oxymetazoline administered as an
aerosol, these drugs have a rapid onset of action
and show few systemic effects.
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
Oral administration results in longer duration of action
but also increased systemic effects.
Combinations of these agents with antihistamines are
frequently used.
The α-adrenergic agonists should be used no longer than
several days due to the risk of rebound nasal congestion
(rhinitis medicamentosa).
α-Adrenergic agents have no place in the long-term
treatment of allergic rhinitis.
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
Corticosteroids
Corticosteroids, such as beclomethasone & triamcinolone,
are effective when administered as nasal sprays.
Topical steroids may be more effective than systemic
antihistamines in relieving the nasal symptoms of both
allergic and non allergic rhinitis.
Treatment of chronic rhinitis may not result in improvement
until 1 to 2 weeks after starting therapy.
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DRUGS USED TO TREAT ALLERGIC
RHINITIS
Cromolyn(membrane stabilizer agent)
Intranasal cromolyn may be useful, particularly
when administered before contact with an
allergen.
To optimize the therapeutic effect of cromolyn,
dosing should occur at least 1 to 2 weeks prior
to allergen exposure.
Due to a short duration of action, cromolyn
requires multiple daily dosing.
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TREATMENT OF COUGH
By :ISRAA OMAR
COUGH
• It is a protective reflex that removes foreign
material and secretion from the bronchi and
bronchioles.
• It is very common adverse effect of the
angiotensin-converting enzyme inhibitors, in
which case ,the drug should be changed in to
alternative drug .
• It can be triggered by inflammation in the
respiratory system ,for example asthma,
pneuomnia,forign body, heart failure, URTI
chronic reflux with aspiration, or by neoplasia
ANTITUSSIVE
• Antitussive drugs act by ill defined effect in the
brain stem , depressing an even more poorly
defined “cough center”.
• All opioid narcotic analgesic have antitussive
narcotic analgesic in doses lower than those
required for pain relief
• They have minimum analgesic and addictive
properties
• Newer agent that only act peripherally on
sensory nerves in bronchi are being assessed
CODIENE
• It is the gold standard treatment for cough
suppression
• It decreases the sensitivity of cough center in the
CNS to peripheral stimuli, decrease the mucosal
secretion which thicken the sputum, and inhibit
ciliary activity
• These therapeutic effect occur at doses lower
than those required for analgesia but still incur
common side effect like constipation, dysphoria,
and fatigue, in addition to addiction potential
DEXTROMETHORPHAN
• Is a synthetic derivative of morphine that
suppresses the response of the central cough
center
• It has no analgesic effect, has low addictive
profile, but may cause dysphoria at higher
doses
• Has significantly better side effect profile than
codeine and has been demonstrated to be
equally effective for cough suppression
PROTUSSIVES
• Protussives are for wet cough.
A) Steam inhalations (alone or with compound
benzoin or menthol or eucalyptus oil).
B) Expectorants: e.g. Guaifensin
These are demulcents and they reduce
viscosity of sputum.
C) Mucolytics e.g. Ambroxol
- systemic mucolytics
- break disulphide bonds of fibres of sputum
(reduce viscosity of sputum).
- have no effect on gastric barriers.
REFRENCES
LIPPINCOTTES PHARMACOLOGY
THANK YOU
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