Colds and flu

The common cold comprises a mixture of viral upper respiratory tract
infections (URTIs). Although colds are self-limiting, many people
choose to buy OTC medicines for symptomatic relief. Some of the
ingredients of OTC cold remedies may interact with prescribed therapy,
occasionally with serious consequences. Therefore, careful attention
needs to be given to taking a medication history and selecting an
appropriate product.
What you need to know
Age (approximate)
Child, adult
Duration of symptoms
Runny/blocked nose
Summer cold
Sneezing/coughing
Generalised aches/headache
High temperature
Sore throat
Earache
Facial pain/frontal headache
Flu
Asthma
Previous history
Allergic rhinitis
Bronchitis
Heart disease
Present medication
Significance of questions and answers
Age
Establishing who the patient is – child or adult – will influence the
pharmacist’s decision about the necessity of referral to the doctor and
choice of treatment. Children are more susceptible to URTI than
adults.
COLDS AND FLU 17
Duration
Patients may describe a rapid onset of symptoms or a gradual onset
over several hours; the former is said to be more commonly true of flu,
the latter of the common cold. Such guidelines are general rather than
definitive. The symptoms of the common cold usually last for 7–14
days. Some symptoms, such as a cough, may persist after the worst of
the cold is over.
Symptoms
Runny/blocked nose
Most patients will experience a runny nose (rhinorrhoea). This is
initially a clear watery fluid, which is then followed by the production
of thicker and more tenacious mucus (this may be purulent). Nasal
congestion occurs because of dilatation of blood vessels, leading to
swelling of the lining surfaces of the nose. This narrows the nasal
passages, which are further blocked by increased mucus production.
Summer colds
In summer colds the main symptoms are nasal congestion, sneezing
and irritant watery eyes; these are more likely to be due to allergic
rhinitis (see p. 49).
Sneezing/coughing
Sneezing occurs because the nasal passages are irritated and congested.
A cough may be present (see p. 29) either because the pharynx
is irritated (producing a dry, tickly cough) or as a result of irritation of
the bronchus caused by postnasal drip.
Aches and pains/headache
Headaches may be experienced because of inflammation and congestion
of the nasal passages and sinuses. A persistent or worsening
frontal headache (pain above or below the eyes) may be due to
sinusitis (see below and p. 199). People with flu often report muscular
and joint aches and this is more likely to occur with flu than with the
common cold (see below).
High temperature
Those suffering from a cold often complain of feeling hot, but in general
a high temperature will not be present. The presence of fever may be
an indication that the patient has flu rather than a cold (see below).
Sore throat
The throat often feels dry and sore during a cold and may sometimes
be the first sign that a cold is imminent (see p. 41).
18 RESPIRATORY PROBLEMS
Earache
Earache is a common complication of colds, especially in children.
When nasal catarrh is present, the ear can feel blocked. This is due to
blockage of the Eustachian tube, which is the tube connecting the
middle ear to the back of the nasal cavity. Under normal circumstances
the middle ear is an air-containing compartment. However, if the
Eustachian tube is blocked, the ear can no longer be cleared by
swallowing and may feel uncomfortable and deaf. This situation
often resolves spontaneously, but decongestants and inhalations can
be helpful (see ‘Management’ below). Sometimes the situation
worsens when the middle ear fills up with fluid. This is an ideal site
for a secondary infection to settle. When this does occur, the ear
becomes acutely painful and can require antibiotics. The infection is
called acute otitis media (AOM). AOM is a common infection in
young children. In the UK about 30% of children visit their GP with
AOM each year and 97% receive antibiotics. The evidence for antibiotic
use is conflicting with some trials showing benefit and others no
benefit for taking antibiotics. Antibiotics have also been shown to
increase the risk of vomiting, diarrhoea and rash, and it is known
that in about 80% of children AOM will resolve spontaneously in
about 3 days without antibiotics.
In summary, a painful ear can initially be managed by the pharmacist.
There is evidence that both paracetamol and ibuprofen are effective
treatments for AOM. However, if pain were to persist or be
associated with an unwell child (e.g. high fever, very restless or listless,
vomiting), then referral to the GP would be advisable.
Facial pain/frontal headache
Facial pain or frontal headache may signify sinusitis. Sinuses are
air-containing spaces in the bony structures adjacent to the nose
(maxillary sinuses) and above the eyes (frontal sinuses). In a cold
their lining surfaces become inflamed and swollen, producing catarrh.
The secretions drain into the nasal cavity. If the drainage passage
becomes blocked, fluid builds up in the sinus and can become secondarily
(bacterially) infected. If this happens, persistent pain arises in the
sinus areas. The maxillary sinuses are most commonly involved. When
the frontal sinuses are infected, the sufferer may complain of a frontal
(forehead) headache. The headache is typically worsened by lying
down or bending forwards.
Flu
Differentiating between colds and flu may be needed to make a decision
about whether referral is needed. Patients in ‘at-risk’ groups
COLDS AND FLU 19
might be considered for antiviral treatment. Flu is generally considered
to be likely if
. temperature is 388C or higher (37.58C in the elderly).
. a minimum of one respiratory symptom (cough, sore throat, nasal
congestion or rhinorrhoea) is present.
. a minimum of one constitutional symptom (headache, malaise, myalgia,
sweats/chills, prostration) is present.
Flu often starts abruptly with sweats and chills, muscular aches and
pains in the limbs, a dry sore throat, cough and high temperature.
Someone with flu may be bedbound and unable to go about usual
activities. There is often a period of generalised weakness and malaise
following the worst of the symptoms. A dry cough may persist for
some time.
True influenza is relatively uncommon compared to the large
number of flu-like infections that occur. Influenza is generally more
unpleasant, although both usually settle with no need for referral.
Flu can be complicated by secondary lung infection (pneumonia).
Complications are much more likely to occur in the very young, the
very old and those who have pre-existing heart or lung disease
(chronic bronchitis). Warning that complications are developing
may be given by a severe or productive cough, persisting high fever,
pleuritic-type chest pain (see p. 59) or delirium.
Asthma
Asthmatic attacks can be triggered by respiratory viral infections.
Most asthma sufferers learn to start or increase their usual medication
to prevent such an occurrence. However, if these measures fail, referral
is recommended.
Previous history
People with a history of chronic bronchitis (defined as a chronic cough
and or mucus production for at least 3 months in at least 2 consecutive
years when other causes of chronic cough have been excluded) may be
advised to see their doctor if they have a badcold or flu-like infection as it
often causes an exacerbation of their bronchitis. In this situation the
doctor is likely to increase the dose of inhaled anticholinergicsandbeta-2
agonists and prescribe a course of antibiotics. Certain medications are
best avoided in those with heart disease, hypertension and diabetes.
Present medication
The pharmacist must ascertain any medicines being taken by the
patient. It is important to remember that interactions might occur
with some of the constituents of commonly used OTC medicines.
20 RESPIRATORY PROBLEMS
If medication has already been tried for relief of cold symptoms
with no improvement and if the remedies tried were appropriate and
used for a sufficient amount of time, referral to the doctor might
occasionally be needed. In most cases of colds and flu, however,
OTC treatment will be appropriate.
When to refer
Earache not settling with analgesic (see above)
Facial pain/frontal headache
In the very young
In the very old
In those with heart or lung disease, e.g. chronic bronchitis
With persisting fever and productive cough
With delirium
With pleuritic chest pain (for further discussion see p. 59)
Asthma
Treatment timescale
Once the pharmacist has recommended treatment, patients should be
advised to see their doctor in 10–14 days if the cold has not improved.
Management
The use of OTC medicines in the treatment of colds and flu is widespread
and such products are heavily advertised to the public. There is
little doubt that appropriate symptomatic treatment can make the
patient feel better; the placebo effect also plays an important part
here. For some medicines used in the treatment of colds, particularly
older medicines, there is little evidence available from which to judge
effectiveness. The pharmacist’s role is to select appropriate treatment
based on the patient’s symptoms and available evidence, and taking
into account the patient’s preferences. Polypharmacy abounds in
the area of cold treatments and patients should not be overtreated.
The discussion of medicines that follows is based on individual
constituents; the pharmacist can decide whether a combination of
two or more drugs is needed.
Decongestants
Sympathomimetics
Sympathomimetics (e.g. pseudoephedrine) can be effective in reducing
nasal congestion. Nasal decongestants work by constricting the
COLDS AND FLU 21
dilated blood vessels in the nasal mucosa. The nasal membranes are
effectively shrunk, so that drainage of mucus and circulation of air
are improved and the feeling of nasal stuffiness is relieved. These
medicines can be given orally or applied topically. Tablets and syrups
are available, as are nasal sprays and drops. If nasal sprays/drops are
to be recommended, the pharmacist should advise the patient not to
use the product for longer than 7 days. Rebound congestion (rhinitis
medicamentosa) can occur with topically applied but not oral sympathomimetics.
The decongestant effects of topical products containing
oxymetazoline or xylometazoline are longer lasting (up to 6 h)
than those of some other preparations such as ephedrine. The pharmacist
can give useful advice about the correct way to administer nasal
drops and sprays.
Problems
The pharmacist should be aware that some of these drugs
(e.g. ephedrine, pseudoephedrine), when taken orally, have the potential
to keep patients awake because of their stimulating effects on the
central nervous system (CNS). In general, ephedrine is more likely to
produce this effect than the other sympathomimetics. It is reasonable
to suggest that the patient avoids taking a dose of the medicine near
bedtime.
Sympathomimetics can cause stimulation of the heart, an increase
in blood pressure, and may affect diabetic control because they
can increase blood glucose levels. They should be used with caution
(current BNF warnings) in people with diabetes, those with
heart disease or hypertension, and those with hyperthyroidism. Hyperthyroid
patients’ hearts are more vulnerable to irregularity, so
that stimulation of the heart is particularly undesirable for such
patients.
Sympathomimetics are most likely to cause these unwanted effects
when taken by mouth and are unlikely to do so when used topically.
Nasal drops and sprays containing sympathomimetics can therefore
be recommended for those patients in whom the oral drugs are less
suitable. Saline nasal drops or the use of inhalations would be other
possible choices for patients in this group.
The interaction between sympathomimetics and monoamine
oxidase inhibitors (MAOIs) is potentially extremely serious; a hypertensive
crisis can be induced and several deaths have occurred in such
cases. This interaction can occur up to 2 weeks after a patient has
stopped taking the MAOI, so the pharmacist must establish any
recently discontinued medication. There is a possibility that topically
applied sympathomimetics could induce such a reaction in a patient
22 RESPIRATORY PROBLEMS
taking an MAOI. It is therefore advisable to avoid both oral and
topical sympathomimetics in patients taking MAOIs. Cautions:
diabetes
heart disease
hypertension
hyperthyroidism
Interactions. Avoid in those taking
MAOIs (e.g. phenelzine)
reversible inhibitors of monoamine oxidase A (RIMAs) (e.g.
moclobemide)
beta-blockers
tricyclic antidepressants (e.g. amitriptyline) – a theoretical interaction
that appears not to be a problem in practice.
Phenylpropanolamine and stroke
A study conducted in the USA showed an association between the
use of phenylpropanolamine (PPA) and haemorrhagic stroke. The
most significant increased risk in the US study was among women
who took PPA in appetite-suppressant products, which are not available
in the UK. It is important to note that there are differences
between the USA and the UK in the way PPA is used as a
non-prescription medicine. The maximum daily dose is 100 mg in
the UK compared with 150 mg in the USA. A review conducted by
the UK Committee on Safety of Medicines in 2000 concluded that
any risk associated with PPA use in preparations and doses used in the
UK appears to be very small. Nevertheless, most UK products
containing an oral decongestant have since been reformulated to
exclude PPA.
Antihistamines (see also p. 53)
Antihistamines can reduce some of the symptoms of a cold: runny nose
(rhinorrhoea) and sneezing. These effects are due to the anticholinergic
action of antihistamines. The older drugs (e.g. chlorphenamine
(chlorpheniramine), promethazine) have more pronounced anticholinergic
actions than do the non-sedating antihistamines (e.g. loratadine,
cetirizine, acrivastine). Antihistamines are not so effective
at reducing nasal congestion. Some (e.g. diphenhydramine) may also
be included in cold remedies for their supposed antitussive action
(see p. 36) or to help the patient to sleep (included in combination
products intended to be taken at night).
Interactions. The problem of using antihistamines, particularly
the older types (e.g. chlorphenamine), is that they can cause
COLDS AND FLU 23
drowsiness. Alcohol will increase this effect, as will drugs such as
benzodiazepines, phenothiazines or barbiturates that have the ability
to cause drowsiness or CNS depression. Antihistamines with known
sedative effects should never be recommended for anyone who
is driving, or in whom an impaired level of consciousness may be
dangerous (e.g. operators of machinery at work).
Because of their anticholinergic activity, the older antihistamines
may produce the same adverse effects as anticholinergic drugs (i.e. dry
mouth, blurred vision, constipation and urinary retention). These
effects are more likely if antihistamines are given concurrently
with anticholinergics such as hyoscine, or with drugs that have
anticholinergic actions such as tricyclic antidepressants.
Antihistamines should be avoided in patients with prostatic hypertrophy
and closed-angle glaucoma because of possible anticholinergic
side-effects. In patients with closed-angle glaucoma they may cause
increased intraocular pressure. Anticholinergic drugs can occasionally
precipitate acute urinary retention in predisposed patients, e.g. men
with prostatic hypertrophy.
While the probability of such serious adverse effects is low, the
pharmacist should be aware of the origin of possible adverse effects
from OTC medicines.
At high doses, antihistamines can produce stimulation rather than
depression of the CNS. There have been occasional reports of fits
being induced at very high doses of antihistamines and it is for this
reason that it has been argued that they should be avoided in epileptic
patients. However, this appears to be a theoretical rather than a
practical problem. Antihistamines can theoretically antagonise the
effects of betahistine.
Interactions:
alcohol
hypnotics
sedatives
betahistine
anticholinergics, e.g. trihexyphenidyl (benzhexol), tricyclics
Side-effects:
drowsiness (driving, occupational hazard)
constipation
blurred vision
Cautions:
closed-angle glaucoma
prostatic obstruction
24 RESPIRATORY PROBLEMS
epilepsy
liver disease
Zinc
Two systematic reviews have found limited evidence that zinc gluconate
or acetate lozenges may reduce continuing symptoms at 7 days
compared with placebo. Thus there is indication of some benefit.
Echinacea
A systematic review of trials indicated that some echinacea preparations
may be better than placebo or no treatment for the prevention
and treatment of colds. However, due to variations in preparations
containing echinacea, there is insufficient evidence to recommend
a specific product.
Vitamin C
A systematic review found that high-dose vitamin C (over 1 g per day)
reduced the duration of colds by about half a day (a reduction of
approximately 15% in duration).
Cough remedies
For discussion of products for the treatment of cough, see p. 34.
Analgesics
For details of analgesics, their uses and side-effects, see p. 201.
Products for sore throats
For discussion of products for the treatment of sore throat, see p. 45.
Practical points
Diabetics
The National Pharmaceutical Association and Diabetes UK jointly
publish a useful list of OTC products and their sugar and sweetener
content. In short-term use for acute conditions, the sugar content of
OTC medicines is less important.
Steam inhalations
These may be useful in reducing nasal congestion and soothing the air
passages, particularly if a productive cough is present. A systematic
review found there was insufficient evidence to judge whether there
might be a benefit from this treatment. For further discussion of
their use, see p. 37. Inhalants that can be used on handkerchiefs,
bedclothes and pillowcases are available. These usually contain
COLDS AND FLU 25
aromatic ingredients such as eucalyptus. Such products can be useful
in providing some relief but are not as effective as steam-based inhalations
in moistening the airways.
Nasal spray or drops?
Nasal sprays are preferable for adults and children over 6 years of age
because the small droplets in the spray mist reach a large surface area.
Drops are more easily swallowed, which increases the possibility of
systemic effects.
For children under 6 years of age drops are preferred because in
young children the nostrils are not sufficiently wide to allow
the effective use of sprays. Paediatric versions of nasal drops should
be used where appropriate. Manufacturers of paediatric drops advise
consultation with the doctor for children under 2.
Prevention of flu
Pharmacists should encourage those in at-risk groups to have an
annual flu vaccination. In the UK the health service now provides
vaccinations to all patients over 65 and those below that age who
have chronic respiratory disease (including asthma), chronic heart
disease, chronic renal failure, diabetes mellitus or immunosuppression
due to disease or treatment. Community pharmacists are in a good
position to use their PMRs to target patients each autumn and remind
them to have their vaccination.
Colds and flu in practice
Case 1
Mrs Allen, a regular customer in her late sixties, asks what you can
recommend for her husband. He has a very bad cold; the worst
symptoms are his blocked nose and sore throat. Although his throat
feels sore, she tells you there is only a slight reddening (she looked this
morning). He has had the symptoms since last night and is not feverish.
He does not have earache but has complained of a headache.
When you ask her if he is taking any medicines, she says yes, quite a
few for his heart. She cannot remember what they are called. You
check the PMR and find that he is taking aspirin 75 mg daily, ramipril
5 mg daily, bisoprolol 10 mg daily and simvastatin 40 mg daily.
Mrs Allen asks you if it’s worth her husband taking extra vitamin C
as she’s heard this is good for colds. She wondered if this might be
better than taking yet more medicines.
26 RESPIRATORY PROBLEMS
The pharmacist’s view
The patient’s symptoms indicate a cold rather than flu. He is
concerned most with his congested nose and sore throat. He is taking
a number of medications, which indicate that oral sympathomimetics
would be best avoided. You could recommend that he take regular
simple painkillers or suck a soothing lozenge or pastille for his sore
throat and that he try a topical decongestant or an inhalation to clear
his blocked nose. The symptoms may take about 1 week before they
start to clear. You offer these alternatives to Mrs Allen to see what she
thinks her husband might prefer. You explain that taking vitamin C
might reduce the time taken for the cold to get better by about half a
day. You show her some vitamin C products and tell her their cost.
You also ask if Mr Allen has had a flu jab as he is in an ‘at-risk’ group.
The doctor’s view
The advice given by the pharmacist is sensible. A simple analgesic such
as paracetamol could help both the headache and sore throat. The
development of sinusitis at such an early stage in an infection would
be unlikely but it would be wise to enquire whether his colds are
usually uncomplicated and to ascertain the site of his headache.
The patient’s view
‘I came to the pharmacist because we didn’t want to bother the doctor.
The pharmacist asked me about which symptoms were causing Pete
(my husband) the biggest problem and he gave me a choice of what to
use. I wanted to know what he thought about vitamin C and he told
me about how it might make the cold shorter. In the end though I
decided not to bother with it because it would have been quite expensive
with the other medicines as well, especially as it was unlikely to
make that much difference. I thought I would give him some fresh
orange juice instead.’
Case 2
A man comes into the pharmacy just after Xmas asking for some
cough medicine for his wife. He says that the medicine needs to be
sugar-free as his wife has diabetes. On listening to him further, he says
she has had a dreadful cough that keeps her awake at night. Her
problem came on 5 days ago when she woke in the morning, complaining
of being very achy all over and then became shivery, and
developed a high temperature and cough by the evening. Since then
her temperature has gone up and down and she hasn’t been well
enough to get out of bed for very long. She takes glipizide and
COLDS AND FLU 27
metformin for her diabetes and he has been checking her glucometer
readings, which have all been between 8 and 11 – a little higher than
usual. The only other treatment she is taking is atorvastatin; she is not
on any antihypertensives. He tells you that she will be 70 next year.
The pharmacist’s view
The history indicates flu. It would be best for this woman to be seen by
her GP. She has been ill for 5 days and has been mostly bedbound
during this time. There are several features that suggest she might be at
higher risk from flu. I would suggest that her husband call the doctor
out to see her, as she does not sound well enough to go to the surgery.
Sometimes people are reluctant to call the doctor as they feel they
might be ‘bothering’ the doctor unnecessarily. The pharmacist’s
support is often helpful.
The doctor’s view
The infection is likely to be flu. She is in the higher-risk group for
developing complications (age and diabetes), so it would be reasonable
to advise referral. Most cases of flu usually resolve within 7 days.
The complications can include acute otitis media, bacterial sinusitis,
bacterial pneumonia and less commonly, viral pneumonia and respiratory
failure. In the USA there are 110 000 admissions per year for
influenza with about 20 000 influenza-related deaths. Over 90% of
these deaths have been in those over 65.
In this situation the doctor would want to check her chest for signs
of a secondary infection. A persisting or worsening fever would point
to a complication developing. There would be little point in prescribing
an antiviral, e.g. zanamivir, as it is only effective if started within
2 days of symptom onset. One review has found it to be effective in
reducing the duration of flu symptoms by about 1 day if started soon
enough. It would also be advisable to check whether or not her
husband had had the flu vaccine. The incubation time for flu is 1–4
days and adults are contagious from the day before symptoms start
until 5 days after the onset of symptoms.