The purpose of
this paper is to discuss the rational use of cough mixtures in
paediatric patients and principles of nonpharmacologic measures
for home management of the coughing infant or child.
Assessment of
the coughing child
Cough is one of
the most common symptoms that paediatric practitioners are asked
to evaluate and manage as cough may be disruptive to the child
and anxiety-provoking for parents. Common complications from
cough include exhaustion, feeding difficulties, insomnia,
musculoskeletal pain, hoarseness, excessive perspiration and
urinary incontinence. Less common complications include cardiac
dysrhythmias, syncope and rib fractures.
Parents may self
medicate the coughing child and the paediatrician must be obtain
a medication history (including the use of alternative
medication) as well as a medical history to exclude diseases
which cause acute or chronic cough (e.g. foreign bodies,
congenital and structural anomalies, infections, postnasal drip,
asthma, cystic fibrosis, GERD,heart failure, external auditory
canal irritation, diaphragmatic lesions and habitual cough ).
Treating the underlying disorder will reduce the stimulation to
cough and one should not provide non-specific cough medications
to such patients as sole therapy.
Management of
the coughing child
If cough is part
of an acute respiratory infection like the common cold, the
doctor must explain the normalcy of a cough as part of the
disease process, the protective role that it may play and the
usually self-limited nature of coughs in common colds caused by
the rhinoviruses, coronaviruses and respiratory syncytial
viruses. However the paediatric patient must be monitored for
complications of the common cold (e.g. sinusitis, Eustachian
tube obstruction, middle ear effusions, bronchitis and
bronchiolitis, bacterial pneumonias and exacerbation of asthma)
and appropriate therapy must be given and patient monitored for
resolution of symptoms. The doctor must exclude perennial
allergic rhinitis as the therapy involves allergen avoidance
measures, symptom specific pharmacotherapy (which must be used
regularly) and immunotherapy for selected cases.
In the coughing
child whose symptoms are suggestive of the common cold, remember
to ask the following questions:
-
Is nasal
congestions or rhinorrhoea the most problematic?
-
Any aches
and pains?
-
Any fever?
-
Symptoms and
signs of pharyngitis
-
Does patient
complain of disturbed sleep?
The paediatric
practitioner who prescribes cough medicines should explain their
therapeutic purposes carefully (for example antitussives
partially suppress but do not eliminate the cough).Such
discussion helps avoid unrealistic expectations. Cough
medications generally are contraindicated in premature infants
and the first few months of life because of their potential
toxicity and risk of respiratory depression.
The paediatric
practitioner must exercise caution when prescribing cough
mixtures to children with diabetes mellitus, bone marrow
depression, liver dysfunction, cardiac disease, hypertension,
thyrotoxicosis and asthma. Leukopenia.agranulocytosis,and
cholestatic jaundice have been rarely reported with the use of
promethazine. The antiemetic action of promethazine may obscure
signs of intestinal obstruction.
Nonpharmacologic measures for home management of the coughing
child
Nondrug therapy
includes increased fluid intake, adequate rest, a nutritious
diet as tolerated, increased humidification (steamy showers or
cool mist vaporisers), saline gargle and nasal irrigation.
Simple, inexpensive remedies such as tea with lemon and honey,
chicken soup and hot broths are soothing and increase fluid
intake in children and teenagers. Slowly dissolving hard candies
or other lozenges in the mouth may soothe an irritated throat.
If nasal congestion or rhinorrhea is the most problematic,
recommend a saline nasal spray (Sterimar nasal spray) and raise
the head of the bed of the sleeping child.
Nondrug therapy
for infants include clearing the nasal passageways with a bulb
syringe, moistened cotton balls to remove crusted nasal
secretions in the anterior nares, positioning the infant in an
upright position to enhance drainage and increase the humidity
of inspired air ( especially when the child is asleep at
night).
Aromatic
inhalations are traditionally used and although the vapour may
contain little of the additive, it encourages deliberate
inspiration of warm moist air which is often comforting in
bronchitis. Inhalations are also used for the relief of nasal
obstruction in acute rhinitis or sinusitis. The use of strong
aromatic decongestants applied as rubs or to pillows is not
advised for infants under the age of 3 months. Aromatic
inhalations include Karvol inhalation capsules, Camphor for
steam inhalation (Vicks) and menthol with eucalyptus inhalation.
Benzoin tincture compound (Friar’s Balsam) is not available in
Singapore.
Camphor ointment
4.7 – 5.3% (Vicks ointment) or menthol ointment 2.6 – 2.8% can
be rubbed on the throat and chest in children above 2 years of
age. Application may be repeated up to three times a day.
Pharmacologic
Therapy for Coughs and colds
There are five
categories of cough medicines: expectorants, mucolytics,
antitussives, decongestants and antihistamines.
(1)
Expectorants
Expectorants are
drugs that increase sputum volume and promote removal of
secretions from the airways. Water is the expectorant used most
commonly, given both orally and by inhalation. It works because
of its demulcent effect in the upper airway.
Guaifenesin (glyceryl
guiaiacolate) which is found in Sudafed expectorant and
Robitussin is the only FDA approved non-prescription
expectorant. Guaifenesin loosens and thins lower respiratory
tract infections and makes minimally productive cough more
productive. Guaifenesin is indicated for the symptomatic relief
of ineffective productive cough but there is a lack of
convincing studies to document efficacy. It should not be used
for persistent cough caused by asthma and is used in children
above two years of age. Side effects include gastrointestinal
symptoms, dizziness, headache and rash.
Mesna (Mistabron)
20% ampoules can be nebulised to facilitate expectoration or
instilled (1 – 2 ml diluted with equal volume of water or
saline) for drainage in maxillary sinusitis.
(2)
Mucolytics
Mucolytic agents
liquefy tenacious secretions and reduce sputum viscosity. These
agents include acetylcysteine (Fluimucil and ACC syrup),
carbocisteine (Rhinathiol 2% syrup) bromhexine HCl (Vasican,
Bisolvan) and ambroxol HCl (Mucosolvan). Mucolytic agents should
not be used in patients with active peptic ulcers as they may
cause gastrointestinal effects and occasional allergic
reactions. They are available for sale after consultation with a
pharmacist.
Dornase alfa(
Pulmozyme) is used in cystic fibrosis as a mucolytic and is
administered by inhalation using a jet nebuliser.
(3)
Antitussives
Antitussives are
the most effective cough modifiers and are divided into two
groups – peripherally acting antitussives and centrally acting
antitussives (which include narcotic and nonnarcotic agents).
They are useful for dry painful coughs.
Peripherally
acting antitussives act by coating or by anesthetizing irritated
orpharyngeal receptors. This group includes the demulcents
(throat lozenges, cough drops, lollipop, and honey) as well as
local anaesthetics (Diflamm is a sugar free product). Local
anaesthetics numb the mouth and tongue and patients should avoid
eating and drinking as long as the numbness persists.
Mouthwashes such as Thymol gargle, Diflamm gargle and Biotene
mouth wash provide temporary relief of sore throats and can only
be used in children who are able to spit out the mouthwash.
Menthol is considered a local antitussive.
Demulcent cough
preparations contain soothing substances such as syrup or
glycerol and examples include Ammonia and Pecacuanha Mixture and
paediatric simple linctus.
Centrally acting
antitussives include
-
Codeine
phosphate (Procodin, Phensedyl, Fedac Compound, Dhasedyl)
Codeine containing antitussives should be avoided in
toddlers under 2 years of age and used with great caution in
young children.
-
Pholcodine (Durotuss
products which are sugar free and Actifed Co.linctus)
-
Dextromethorphan(non narcotic)
Codeine and
Pholcodine are contraindicated in patients with impaired
respiratory reserve (e.g. asthma) and patients who receive other
respiratory depressants. Codeine is a Pregnancy Category C drug
and mothers should not breast-feed while taking codeine. Codeine
is effective but it is constipating and can cause dependence.
Morphine and
methadone hydrochloride are used to control distressing cough in
terminal disease.
Dextromethorphan
is a non-narcotic antitussive and it has no analgesic, sedative,
respiratory depressant or addictive properties at the usual
antitussive doses. Dextromethorphan is approximately equipotent
with codeine and is used to suppress a cough associated with
allergy or common cold in children older than 2 years of age. It
has a wide margin of safety but it does have neurologic,
cardiovascular and gastrointestinal effects that are dose
related. Additive CNS depression occurs if Dextromethorphan is
used together with antihistamines, alcohol and psychotropic
medications.
(4)
Decongestants
Decongestants
are alpha-adrenergic agonists (sympathomimetics) and can be
given topically or systemically and are used to relieve nasal
congestion by shrinking nasal mucosa and increasing airway
patency.
Non prescription
intranasal decongestants include oxymetazoline (Iliadin) and
xylometazoline (Otrivin, Afrin) nose drops and rhinitis
medicamentosa occurs when these topical decongestants are used
longer than 3 to 5 days.
Oral
decongestants include ephedrine and pseudoephedrine (phenylpropanolamine
products have been withdrawn by FDA). Adverse effects include
cardiovascular and CNS stimulation and these effects are more
prominent in children and elderly. Oral decongestants have drug
interactions with furazolidine, tricyclic antidepressants,
urinary acidifiers and urinary alkalinizers ( e.g. sodium
bicarbonate).
Decongestants
may exacerbate diseases like hypertension, hyperthyroidism,
diabetes, heart disease and elevated intraocular pressure.
(5)
Antihistamines (oral)
Sedating first
generation antihistamines may decrease the rhinorrhoea
associated with the common cold by about 30% through
anticholinergic effect.
Diphenhydramine
may have a direct suppressive effect on the medullary cough
centre and belongs to the most sedating group of ethanolamines.
Antihistamines
are used primarily for the relief of symptoms of allergic
rhinitis ( itch, sneeze, rhinorrhoea) and can be used as
sedatives, antiemetics, antitussives, antimotion-sickness
agents. An unapproved indication is chronic idiopathic urticaria.
Antihistamines have CNS depressive or stimulatory effects
depending on dose and types of antihistamines. The alkylamines (chhlorpheniramine
and brompheniramine) are considered the least sedating of the
sedating antihistamines.
Patients with
lower respiratory tract disease should use antihistamines with
caution. The sedating antihistamines are photosensitizing drugs
as well. Children may experience paradoxical excitation with
sedating antihistamines.
