Important aspects of prescribing information relevant to primary healthcare are covered in this section specifically for the drugs recommended in this CKS topic. For further information on contraindications, cautions, drug interactions, and adverse effects, see the electronic Medicines Compendium (eMC) (http://emc.medicines.org.uk), or the British National Formulary (BNF) (www.bnf.org).

• Oral flucloxacillin is recommended for empirical treatment of Staphylococcus aureus infections.
• Oral erythromycin (or clarithromycin if erythromycin is not tolerated) are alternatives for people with penicillin allergy.
• If there is no response to treatment, or if the infection is recurrent or chronic, the choice of antibiotic should ideally be guided by sensitivities.

• Flucloxacillin has a narrow spectrum of activity, and is active against most susceptible Gram-positive cocci, including beta-lactamase–producing staphylococci and streptococci. However, it is not active against MRSA (methicillin-resistant Staphylococcus aureus), which is increasingly prevalent in the UK. It diffuses well into most tissues, so is suitable for skin and soft tissue infections [Finch et al, 2003].
• Erythromycin and clarithromycin have a broad spectrum of activity and are active against most sensitive Gram-positive cocci (including staphylococci and streptococci) and some Gram-negative cocci and anaerobes [Finch et al, 2003].
• Clarithromycin may be used in people who are known not to tolerate erythromycin. It is more effective against common pathogens than erythromycin, and has fewer gastrointestinal adverse effects [Finch et al, 2003]. However, it is markedly more expensive than erythromycin.
• Azithromycin (and other macrolides) are not recommended for empirical treatment as there are concerns about increasing resistance [McNulty, Personal Communication, 2006].

• For empirical antibiotic treatment, a 7-day course is recommended for boils, carbuncles, folliculitis, staphylococcal paronychia, and staphylococcal whitlow (if antibiotics are indicated).
• In chronic cases of furunculosis, carbuncles, or folliculitis, an initial 7-day course followed by review seems reasonable. However, some people may need a longer course to clear chronic infection (e.g. 6–8 weeks), although this should be discussed with a specialist. Choice of antibiotics in chronic cases should be guided by sensitivities.

• These recommendations are pragmatic advice. CKS found no randomized controlled trials that studied the effectiveness of antibiotic treatment (or the length of antibiotic course needed) for boils, carbuncles, folliculitis, staphylococcal paronychia, and staphylococcal whitlow.

Flucloxacillin

• Flucloxacillin has been associated with an increased risk of hepatic disorders, namely hepatitis and cholestatic jaundice.
• The Committee on Safety of Medicines (CSM) advises that hepatic reactions may occur up to 2 months after treatment with flucloxacillin has stopped. Risk factors include treatment for more than 14 days and increasing age. The dose and route of administration do not appear to affect this risk.

Erythromycin and clarithromycin

• Erythromycin commonly causes gastrointestinal adverse effects, especially at higher doses. If this is known to occur, consider prescribing clarithromycin instead.
• Erythromycin and clarithromycin can increase the levels of certain other drugs (e.g. theophylline, carbamazepine) and can potentiate the effects of warfarin.
• They can also prolong the QT interval. If possible, avoid giving erythromycin or clarithromycin if the person is already taking a drug that can potentially prolong the QT interval (e.g. antiarrhythmics, antipsychotics, tricyclic antidepressants) or if the person has hypokalaemia, which also increases the risk of QT prolongation.
• If they are taken with a statin, there is an increased risk of myopathy.

Ibuprofen

• As with other nonsteroidal anti-inflammatory drugs, ibuprofen may worsen or precipitate gastrointestinal haemorrhage, asthma, hypertension, renal impairment, or cardiac failure. Avoid ibuprofen if there is a history of peptic ulcers, and in pregnant women.

• A solution of chlorhexidine or triclosan in a detergent vehicle is generally suitable. For example:
• Hibiscrub^® and Hydrex^® Surgical Scrub contain chlorhexidine and are surfactant- (and not alcohol-) based.
• Aquasept^® skin cleanser and Ster-Zac bath concentrate^® contain triclosan and are also surfactant- (and not alcohol-) based.
• An antiseptic-emollient product is recommended for application to the face, or if the person suffers from dry or inflamed skin. For example:
• The Dermol^® range contains benzalkonium chloride and chlorhexidine (antibacterials) with liquid paraffin and isopropyl myristate (emollients).
• Emulsiderm^® bath additive contains benzalkonium chloride (antibacterial) with liquid paraffin and isopropyl myristate (emollients).
• These recommendations are pragmatic advice. Using a detergent-based rather than an alcohol-based product is less likely to irritate the skin. For those with sensitive skin, using a product that combines an antibacterial component with an emollient is least likely to irritate the skin, although contact sensitization to the antibacterial component may still occur with prolonged use.