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OTC casebook: sore throat


OTC casebook: sore throat

By Alan Nathan


It is December. A woman brings her daughter into the Casebook Pharmacy and asks for something for her sore throat, which she has had for the past few days.

In response to pharmacist Eve’s questions the mother says that her daughter is 12 years old, is rather hoarse and has been sweating a little, and that her temperature is slightly above normal. Further questioning reveals that the girl does not have rhinorrhea or any sinus pressure.

The mother also tells Eve that she has been giving her daughter some throat pastilles that she had at home, which contained an antibacterial and a local anaesthetic, but they have not helped much.



What might the girl be suffering form?

What action should be taken in this case?

What are the main features of streptococcal laryngitis and pharyngitis?

In what other more serious conditions is sore throat a major symptom?

Which drugs can cause sore throat as an indicator of immunosuppression?

What OTC preparations are available for the treatment of sore throat?



1. Given the history and symptoms described, the girl is unlikely to have a common cold. She may possibly be suffering from acute streptococcal pharyngitis, a common condition affecting children and teenagers during the winter and early spring. However, a bacterial cause of pharyngitis is relatively uncommon and viruses are reponsible for the large majority of pharyngeal and laryngeal infections.

2. If the sore throat persists for more than 7 to 10 days, or for 24-48 hours if very painful, the girl sould be referred to her GP for confirmation of Eve’s findings and for a throat swab to be taken to determine whether the infection is bacterial or viral.

3. Beta-haemolytic streptococcal infection causes inflammation of one or more of the tonsils, larynx or pharynx. Tonsillitis occurs most frequently in children and young adults; symptoms include: pain in the throat and on swallowing and which may be referred to the ears; headache; loss of voice; fever; malaise; small children may complain of abdominal pain. On examining the throat, there will be redness of the pharynx and tonsils, with swelling of the tonsils and possibly a purulent discharge; the lymph glands on the neck will be swollen and painful. Similar symptoms occur in laryngitis and pharyngitis, where a principal symptom is hoarseness. 90% of cases of sore throat resolve within a week, irrespective of whether the cause is viral or streptococcal. In 40% of cases, symptoms settle within three days.


a) Glandular fever (infectious mononucleosis, IM):  a normally self-limiting infection caused by Epstein-Barr virus, a human herpes virus. The condition occurs most commonly among populations of young adults, such as college students. Symptoms include low-grade fever, fatigue and prolonged malaise.  Patients normally recover within 6 weeks without treatment, but symptoms may persist for several months after the acute infection has resolved. Features of IM include: sore throat with enlarged tonsils; a fine macular non-pruritic rash, which rapidly disappears; oedema of the eyelids; lymphadenopathy, especially neck glands; nausea and anorexia.

b) Oral thrush (candidiasis): a yeast infection, causing sore throat and mouth. Its characteristic feature is curd-like white patches in the mouth, which can be easily removed leaving an underlying red base that is usually painless.

c) Cancer: carcinoma of the larynx and tonsils commonly present with sore throat and dysphagia, and also referred ear pain. These conditions have a strong link with smoking and excessive alcohol intake and are more common in men than women.

5. Drugs which can cause immunosuppression, of which which sore throat is a symptom, include:

  • antithyroid drugs: carbimazole, propylthiouracil (there is also a long list of drugs with which these interact to further increase the risk, see BNF);
  • antiepileptics: carbamazepine, valproate;
  • antibiotics: penicillin, chloramphenicol, co-trimoxazole
  • cytotoxic drugs
  • NSAIDs: indomethacin, naproxen
  • allopurinol
  • antidepressants: mianserin, mirtazapine
  • some antipsychotics, clozapine in particular.


Sore throat treatments contain demulcents, antibacterials and local anaesthetics, and many products contain combinations of these. One sore throat lozenge contains flurbiprofen, an NSAID.


Sucking anything produces saliva, lubricating and soothing inflamed tissues and washing infecting organisms off them. Any lozenge or pastille, regardless of ingredients, will do this. Any non-medicated glycogelatin-based demulcent pastilles, such as glycerin, lemon and honey pastilles, or boiled sweets, may be as effective as anything for soothing a sore throat, and research published very recently has found that honey is superior to usual care for improving symptoms of upper respiratory tract infection. . Because they contain no medicament demulcents can be used as often as necessary to stop the throat feeling dry, thereby relieving discomfort. Some products contain ingredients with volatile constituents, e.g. eucalyptus oil and menthol, which produce a sensation of clearing blocked nasal and upper respiratory passages and can be useful in relieving other symptoms of colds. The main disadvantage of most demulcent throat lozenges and pastilles is their high sugar content.


The antibacterial compounds used in  sore-throat lozenges include amylmetacresol, 2,4-dichlorobenzyl alcohol, hexylresorcinol, chlorhexidine and benzalkonium chloride; they are unlikely to be effective against the rhinoviruses that are largely responsible most sore throats for the common cold. A sore throat complicated by a secondary bacterial infection, such as tonsillitis, would normally be treated with a systemic antibiotic. Gargles have the same drawback as lozenges insofar as most have no proven antiviral activity. In addition, contact time with infected tissue is extremely short. The main action of gargles is the mechanical removal of microbes from the pharynx, but levels of contamination build up again very quickly.

Local anaesthetics and anti-inflammatories

A local anaesthetic or anti-inflammatory may be helpful if swallowing is uncomfortable. Local anaesthetics can cause sensitisation in some individuals with prolonged use, so usage should be limited to 5 days. Benzocaineand lidocaine are the local anaesthetics included in sore-throat lozenges and sprays. The NSAID benzydamine is included in a rinse/gargle preparation, and flurbiprofen is available in a lozenge.








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