Medical Aspects
ANATOMY OF NOSE
The nose contains shelf-like structures called
turbinates, which help trap particles entering the
nasal passages. Material deposited in the nose is
transported by ciliary action to the back of the
throat in 10-15 minutes.
Cold viruses are believed to be carried to the back
of the throat where they are deposited in the area
of the adenoid. The adenoid is a lymph gland
structure that contains cells to which cold viruses
attach.
COMMON COLD
A common cold is an illness caused by a virus
infection located in the nose. Colds also involve
the sinuses, ears, and bronchial tubes.
Commoncold also cause other
symptoms depending upon the virus
Cough
Post Nasal drip
Possible complication include
Bronchitis
Sinusitis
Pneumonia
Antihistamines: Effects
Skin & C-V
Reduce capillary permeability, wheal-and-flare
formation, itching, flushing ,vasodilation
Anticholinergic
Drying effect that reduces nasal, salivary, and
lacrimal gland secretions (runny nose, tearing, and
itching eyes)
Sedative
Some antihistamines cause drowsiness
Antihistamines: Indications
Management of:
Nasal allergies
Seasonal or perennial allergic rhinitis
(hay fever)
Allergic reactions
Motion sickness
Sleep disorders
Antihistamines: Indications
(cont'd)
Also used to relieve symptoms
associated with the common cold
Sneezing, runny nose
Palliative treatment, not curative
Antihistamines: Side effects
Anticholinergic (drying) effects, most
common
Dry mouth
Difficulty urinating
Constipation
Changes in vision
Drowsiness
Mild drowsiness to deep sleep
Antihistamines: Two Types
Traditional
Nonsedating/peripherally acting
Traditional Antihistamines
Older
Work both peripherally and centrally
Have anticholinergic effects, making
them more effective than nonsedating
agents in some cases
Examples: diphenhydramine ;
chlorpheniramine
Mechanism of action of
Decongestant
Nasal decongestants belong to the
pharmacological class of sympathomimetic
amines. Decongestant stimulates alpha-
adrenergic agonist, by constriction of blood
vessels, reducing its supply to the nose,
decrease the amount of blood in sinusoid
vessels and decrease mucosal edema.
Antitussives: Indications
Used to stop the cough reflex when the
cough is nonproductive and/or harmful
Antitussives: Side Effects
Benzonatate
Dizziness, headache, sedation, nausea, and
others
Dextromethorphan
Dizziness, drowsiness, nausea
Opioids
Sedation,nausea, vomiting,
lightheadedness, constipation
DEXTROMETHORPHAN
Dextromethorphan is a synthetically produced substance that is related to
codeine. It has central cough suppressant action but it does not feature the
untoward effects of the opioids: it does not have analgesic, sedating or
constipating effects. Its metabolism is genetically polymorphous, similar to
the codeine metabolism. Since its metabolites can be traced in urine,
dextromethorphan is suitable as a testing substance for the definition of the
respective phenotype. The pharmacological potential of dextromethorphan
does not appear to be completely exploited yet. Dextromethorphan is a
potent antitussive agent that is suitable for dry cough.
Cough is an important defensive reflux that may be triggered from either
laryngeal or lower airway efferents.
Cough can be initiated by a variety of irritants that enter the
tracheobronchial tree by inhalation or by aspiration.
Elimination of an exogenous inciting agent or an endogenous trigger is
usually effective in treating cough when such a precipitation can be
identified.
Cough may be treated by antitussives that act on the peripheral sites or on
the CNS.
Codeine, pholcodine and dextromethorphan are some of the commonly used
antitussives. However, codeine should not be used in children as it has more
side-effects and can cause dependence.
Dextromethrophan is a widely used antitussive and offers certain
advantages over codeine and pholcodine.
