Antibiotics Prescribing Guidelines

Dr Tom Leach

8 years ago

Introduction

These antibiotic guidelines are intended to give a basic overview of the types of antibiotic used to treat various kinds of infection. They should not be used as clinical guidelines. Resistance patterns and drug approvals vary from country to country, and hospital to hospital and as such national and / or local antibiotic guidelines should be used wherever possible. If uncertainty still exists, you may wish to contact your local infectious diseases consultant for specific advice.

Antibiotic Guidelines in Adults

Key:

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Penicillin allergy alternative (generally this is erythromycin or clarithromycin)

Remember that the doses below are adults doses; children’s doses (and the drugs and antibiotic guidelines used for children) may be different.

	Condition	Drug	Dose	Info
U R O L O G Y	UTI – uncomplicated	Nitrofurantoin Trimethoprim Cefalexin – and fluids Co-amoxiclav/ciprofloxacin used for resistant organisms MRSA – nitrofurantoin and trimethoprim and doxycycline	50mg qds – 3 days 200mg bd – 3 days 500mg bd – 3 days	Nitro drugs is contra-indicated when GFR <50, so be careful in the elderly! always assume in men that a UTI is complicated until proven otherwise
	Acute Prostatitis	Ciprofloxacin Trimethoprim Tetracycline	500mg bd – 28 days 200mg bd – 28 days 500mg bd – 28 days
	Pyelonephritis (and complicated UTI’s)	Ciprofloxacin / cefuroxime Co-amoxiclav IV – gentamycin	500mg bd – 7 days 625mg tds – 14 days 5mg/Kg when pathogen unknown	Nitrofurantoin is NOT effective.
	Genital bacterial infections (General)	Metronidazole	400mg bd 5-7 days
	PID	Metronidazole Doxycycline	400mg bd 14 days 100mg bd 14 days
	Chlamydia	Doxycycline	100mg bd 7 days	Can also give Azithromycin one off dose to increase compliance
	Gonorrhoea	Ciprofloxacin Amoxicilin Probenicid	500mg single dose 3g single dose 1g single dose
	Herpes virus (and for freq. Reccur.)	Aciclovir Aciclovir	200mg x5 for 5 days 400mg bd – 6 months	Herpes virus also causes shingles. In which case, give 800mg x5, for 5 days
	Vaginal fungal infections	Clotrimazole pessary	500mg – single dose
R E S P I R A T O R Y	Lower respiratory tract infection (LRTI) in previously well patients	Amoxicillin Erythromycin	500mg tds – 10 days 1g bd – 10 days	Amoxicillin can cause allergic reaction in those allergic to penicillin. Clarithromycin is the alternative used normally.
	COPD acute exacerbation	Amoxicillin Co-amoxiclav Ciprofloxacin Clarithromycin	500mg tds – 7 days 625mg tds – 7days 500mg bd – 7 days 500mg bd – 7 days
	Whooping cough	Erythromycin	500mg qds – 14 days
	Bronchiolitis	————————–	————————-	A LRT infection usually in the first 2 years of life. Viral; don’t give antibiotics!
	Bronchiectasis	Amoxicillin Doxycycline	500mg tds – 14 days 100mg bd 14 days
	Pneumonia	0 – Amoxicillin (clarithro) 1 – Amoxicillin + clarithro. 2- IV Amox. + clarithro. 3-5 – IV augmentin + clarith	1g (500mg) single dose, or 500mg (500mg) – 7 days 500mg (each) – 7 days 1g IV + 500mg IV – review @ 24hours	Treatment is dependent on CURB 65 score.
E N T	Otitis Media	Amoxicillin Erythromycin Co-amoxiclav	500mg tds – 10 days 250mg qds – 5 days 375mg tds – 5 days	Special rules apply for children (often antibiotics are not used
	Otitis Externa Topical: Oral: For fungus:	Locorten-viofrom Betnesol-N Flucloxacillin Erythromycin Clotrimazole 1% solⁿ	3 drops bd – 7days 3 drops qds – 7 days 250mg qds – 7 days 250mg qds – 7 days 3 drops tds – 4 weeks	Don’t forget anaesthesia – it is very painful! If this condition is recurrent consider underlying pathology such as diabetes, or exfoliative skin conditions.
	Dental infections(gingivitis and abscess)	Penicillin V – AND – Chlorohexidine mouthwash Erythromycin Metronidazole	500mg qds – 5-7 days 10 ml bd 500mg qds – 5-7 days 400mg tds – 5-7 days
	Pharyngitis	Penicillin V Erythromycin	500mg qds – 7 days 1g bd – 7 days	Remember – most sore throats are viral and you should not prescribe anything – see the algrythmn. It is estimated up to 75% of patients are prescribed antibiotics – probably due to patient expectations and the doctor not wanting to let them down
	Oral candidiasis	Nystatin (can be pastille or suspension) Fluconazole (tablet)	100k units 4xday – 7days 50mg od – 7-14 days	Remember – this is common in immunosupressed individuals. Fluconazole can also be used in loads of other fungal infections
	Acute Sinusitis	Amoxicillin Oxytetracycline	500mg tds – 5 days 250mg qds – 5 days
S K I N	Animal and human bites	Co-amoxiclav	375 tds – 7 days	Cat and dog bites are generally infected with anaerobic bacteria
	Impetigo / Cellulitis	Flucloxacillin Fusidic acid cream Clarithrymycin Erythromycin	500mg qds – 5-14 days Qds – 5 days 500mg bd 7-14 days	Consider combining both oral and topical treatments. When cellulitis, give flucoloxacillin and penicillin.
	ACNE	Benzoyl peroxide cream +/- Clindamycin / tetracycline Oxytetracycline doxycycline	This is not an antibiotic. If infected 500mg bd – 3 months+ 100mg od – 3 months+	Only give antibiotics when this is infected.
	MRSA colonation / infection AND/OR patient systemically unwell	Vancomycin IV –AND- Oral ciprofloxacin	500mg bd	Make sure you give two antibiotics! Also advisable to cover infected area with iodine or chlorohexadine dressing
	Fungal hair skin and nails	Various topical and oral agents – too many to list	FLUCONAZONE – is probably the most widely used agent.	Fluconazole is given once weekly
	Mastitis	Metronidazole
	Necrotising Fascitis	Give all of the following: Vanomycin IV Clindamycin IV Ciprofloxacin IV	900mg tds 400mg bd	Do this whilst you are waiting for advice! Seek urgent surgical and microbiological advice
G I	Primary care: 1)Salmonella / shingella 2)Campylobacter 3)Giardia	1)Ciprofloxacin 2)Erythromycin 3)Metronidazole	500mg bd – 3 days 500mg bd – 3 days 2g od – 3 days	The vast majority are self- limiting and do not require intervention. When causatory organism is not known, use ciprofloxacin. Note that the public health department needs to be notified of all cases of food poisoning. Also remember that many antibiotics can cause diarrhoea! – by killing the ‘good’ bacteria, and allowing the resistant strains to multiply . Metronidazole is good because it is good at attacking anaerobic bacteria.
	Peritonitis	Amoxicillin – AND – Gentamycin – AND – Metronidazole Vancomycin (instead of amoxicillin)	1g IV tds 5mg/Kg od 500mg IV tds	Use 3 antibiotics!
	Intra-abdominal sepsis – hospital acquired Oral continuation:	Peperacillin – AND – Gentamycin Amoxicillin – AND – ciprofloxacin – AND – Metronidazole	4.5g IV tds 5mg/Kg od 500mg tds 500mg bd 400mg tds	Consider MRSA – particularly if hospital acquired. If it is present use IV vanomycin
	Cholecystitis	–	–	Should be managed surgically, and antibiotics only used when there are signs of systemic infection
	Severe Acute pancreatitis	–	–	Very severe disease requires antibiotic therapy. Usually involving co-amoxiclav / amoxicillin.
	Sepsis – this is a word that basically means serious systemic inflammation caused by infections (SIRS). The term septicaemia is an older word that has a similar meaning.	Tazocin* Gentamicin	4.5g every 8 hours 5mg/Kg – but – only use if there is septic shock with hypotension	Patients in shock and who are seriously ill should be started on fluid replenishment and antibiotics right away without waiting for any test results.
O T H E R S	Trauma	Flucloxacillin IV + Metronidazole IV OR – if more serious Co-amoxiclav IV	1g 6hrs – review@24hrs 500mg 8 hrs 1.2g tds – 3 days+	These treatments are prophylactic for bone/joint infections.
	TB	Isoniazid Rifampicin Pyrazinamide Ethambutol	300mg od – 6 months 600mg od – 6 months 2g daily – 2 months 15mg/Kg od – 2 months	Ethambutol can be omitted if HIV negative, and low risk of isoniazid resistance (i.e. no previous treatment for TB) there are several combination pills available for use after discharge from hospital
	Meningitis	Ceftriaxone IV Chloramphenicol	2g bd until improvement, then 3g od	All patients with suspected meningitis need to receive the first dose within 30 minutes of arrival
	Infective Endocarditis	Indolent (not acutely unwell) Benzylepenicillin IV + Gentamicin IV Acutely unwell (or IV drug user) Flucloxacillin IV	1.2g 6x a day 1mg/Kg 3x a day 2g qds if <85Kg 2g 6xday >85Kg	Note that the dose of flucloxacillin varies with patient’s weight.
	Diabetic Foot	Flucloxacillin + Amoxicillin clarithromycin	1g qds 500mg qds 500mg bd

*brand name for piperacillin + tazobactam combination

Antibiotic guidelines and alcohol

Of all the antibiotics, only METRONIDAZOLE truly reacts with alcohol. It will cause severe vomiting and GI disturbance if alcohol is taken with the drug.

However, you should still advise patients that taking alcohol with antibiotics may prolong the recovery time, as it is generally a toxin.

Introduction

Antibiotic Guidelines in Adults

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