Antibiotic Treatments in Adults, Summary of Regimens

Dose regimens for common bacterial infections.

Summary of antibiotic treatments in adults
CENTRAL NERVOUS SYSTEM
Infection Treatment options and dose Option in penicillin allergy Notes
Suspected meningococcal disease (meningitis with non-blanching rash/meningococcal septicaemia) Benzylpenicillin (penicillin G) 1.2g single dose by iv/im inj while arranging transfer to hospital (if administering im, give as proximally as possible)
Urgent transfer to hospital should not be delayed in order to give antibiotics
EAR, NOSE AND THROAT
Infection Treatment options and dose Option in penicillin allergy Notes
Acute diffuse otitis externa Flucloxacillin 250–500mg qds for 7 days Erythromycin 250–500mg qds or clarithromycin 250–500mg bd for 7 days Oral antibiotics rarely indicated. Consider if signs of systemic infection or if infection is spreading outside the ear canal.
Acute otitis media Amoxicillin 13.3mg/kg (max 1g) tds for 5 days Clarithromycin 250–500mg bd for 5 days or erythromycin 250–500mg qds for 5 days Routine prescription of antibiotics not recommended in uncomplicated cases.
Acute sinusitis Amoxicillin 500mg–1g tds for 7 days or phenoxymethylpenicillin (penicillin V) 500mg qds for 7 days Doxycycline 200mg stat then 100mg od for 6 days or erythromycin 500mg qds or clarithromycin 500mg bd for 7 days Antibiotics not recommended unless high risk of complications or acute bacterial sinusitis suspected.
If no improvement after 48 hrs or poorly tolerated:
Co-amoxiclav 500/125mg tds for 7 days
If no improvement after 48 hrs or poorly tolerated: azithromycin 500mg od for 3 days
Dental abscess

Amoxicillin 500mg tds for 5 days or phenoxymethylpenicillin (penicillin V) 500mg–1g qds for 5 days

If infection severe or spreading, add metronidazole 400mg tds for 5 days (or if not tolerated, clindamycin 300mg qds for 5 days)

Clarithromycin 500mg bd for 5 days Antibiotics recommended only if severe infection, systemic symptoms or high risk of complications. Treat if no access to dentist, advise urgent dental consultation.
Sore throat (pharyngitis, tonsillitis) Phenoxymethylpenicillin (penicillin V) 500mg qds for 10 days Erythromycin 250mg–500mg qds or clarithromycin 250mg–500mg bd for 5 days Antibiotics recommended only if risk of serious complications, marked systemic upset, valvular heart disease or Centor score ≥3. Consider delayed prescribing.
EYE
Infection Treatment options and dose Option in penicillin allergy Notes
Acute infective conjunctivitis Chloramphenicol 1 drop every 2 hrs for 2 days then every 4 hrs or apply oint at night (if drops used during the day) or tds or qds (if used alone); continue for 48 hrs after cure. Remove contact lenses.
Routine prescription of topical antibiotics not recommended in uncomplicated cases. Consider delayed prescribing.
Fusidic acid 1% 1 drop bd, continued for 48 hrs after cure.
GASTROINTESTINAL TRACT
Infection Treatment options and dose Option in penicillin allergy Notes
Acute diverticulitis (mild, uncomplicated)
Co-amoxiclav 500/125mg tds for 7 days Metronidazole 400mg tds + ciprofloxacin 500mg bd for 7 days Refer to hospital if symptoms persist after 48 hrs despite conservative management.
Gastroenteritis

Antibiotics rarely indicated.
H. pylori

Refer to summary of NICE recommendations for the eradication of H. pylori.
GENITAL TRACT
Infection Treatment options and dose Option in penicillin allergy Notes
Acute pelvic inflammatory disease (PID)

Low risk of gonococcal infection: Ofloxacin 400mg bd + oral metronidazole 400mg bd for 14 days. Alternatively, ceftriaxone 500mg single dose by im inj, then doxycycline 100mg bd + metronidazole 400mg bd, both for 14 days; or ceftriaxone 500mg single dose by im inj, then azithromycin 1g per week for 2 weeks.

High risk of gonococcal infection: Ceftriaxone 500mg single dose by im inj, then doxycycline 100mg bd + metronidazole 400mg bd, both for 14 days.


Pregnant women with suspected PID require hospital admission for iv antibiotics. Exclude ectopic pregnancy before starting treatment. Refer patient to sexual health clinic for screening/treatment of partners. Test for STIs ideally before starting antibiotics.
Acute uncomplicated
gonorrhoea
Ceftriaxone 500mg single dose by im inj + azithromycin 1g single dose If infection sensitive to quinolones: Ciprofloxacin 500mg + azithromycin 1g, or ofloxacin 400mg + azithromycin 1g, all as single doses Ideally, refer patient to sexual health clinic. Partners should also be treated.
If im inj contraindicated or refused: Cefixime 400mg orally as single dose + azithromycin 1g single dose
Bacterial vaginosis Oral metronidazole 400mg bd for 5–7 days (or a single dose of 2g— not recommended in pregnancy or lactation)
Intravaginal metronidazole 0.75% gel: 1 applicatorful every night for 5 nights
Intravaginal clindamycin 2% cream: 1 applicatorful every night for 7 nights
Chlamydia (uncomplicated) Azithromycin 1g single dose
Partners should also be treated.
Doxycycline 100mg bd for 7 days
In pregnancy or lactation: Azithromycin 1g single dose or amoxicillin 500mg tds for 7 days or erythromycin 500mg qds for 7 days
RESPIRATORY TRACT
Infection Treatment options and dose Option in penicillin allergy Notes
Acute bronchitis Amoxicillin 500mg tds for 5 days Clarithromycin 500mg bd for 5 days Antibiotics not recommended for patients who are otherwise well. Consider delayed prescribing.
Doxycycline 200mg stat then 100mg od for 4 days
2nd-line treatment: Co-amoxiclav 500/125mg tds for 5 days
Community-acquired
pneumonia
Amoxicillin 500mg tds for 7 days Doxycycline 200mg stat then 100mg od for 7–10 days or clarithromycin 500mg bd for 7 days Consider doxycycline alone or with amoxicillin if Mycoplasma pneumoniae suspected.
Severe infection: Consider amoxicillin 500mg tds + clarithromycin 500mg bd, or doxycycline (see next column); treat for 7–10 days
Exacerbation of COPD Amoxicillin 500mg tds for 5 days Erythromycin 500mg qds or clarithromycin 500mg bd for 5 days

Doxycycline 200mg stat then 100mg od for 4 days
Risk factors for antibiotic resistance: Co-amoxiclav 500/125mg tds for 5 days
SKIN AND SOFT TISSUE
Infection Treatment options and dose Option in penicillin allergy Notes
Acute cellulitis Flucloxacillin 500mg qds for 7 days Erythromycin 500mg qds or clarithromycin 500mg bd for 7 days Add ciprofloxacin (750mg bd for 7 days) if exposed to fresh water or doxycycline (100mg bd for 7 days) if exposed to salt water.
Mild facial infection: Co-amoxiclav 500/125mg tds for 7 days
Bites: animal
(cats and dogs)
Co-amoxiclav 250/125mg–500/125mg tds for 7 days Metronidazole 400mg tds + doxycycline 100mg bd for 7 days Give antibiotics for all cat bites, puncture wounds, bites to the hand, foot, face, joints, tendons or ligaments, or if suspected fracture. Antibiotics not usually required if bite >48 hours old and no sign of infection.
Metronidazole 400mg tds + oxytetracycline 250–500mg qds for 7 days
Bites: human Co-amoxiclav 250/125mg–500/125mg tds for 7 days Metronidazole 400mg tds plus: doxycycline 100mg bd or erythromycin 250–500mg qds or clarithromycin 250–500mg bd, all for 7 days Prophylactic antibiotic recommended for all bites <72 hours old, even if no sign of infection.
Impetigo Localised non-bullous infection: Fusidic acid 2% cream/oint tds–qds for 7 days
If fusidic acid ineffective: retapamulin 1% oint bd for 5 days
Extensive, severe or bullous infection or if impractical to use topical therapy: Flucloxacillin 250–500mg qds for 7 days Clarithromycin 250–500mg bd for 7 days or erythromycin 250–500mg qds for 7 days
URINARY TRACT
Infection Treatment options and dose Option in penicillin allergy Notes
Acute bacterial prostatitis Ciprofloxacin 500mg bd for 28 days or ofloxacin 200mg bd for 28 days Review treatment when urine culture results available.
If quinolone contraindicated: Trimethoprim 200mg bd for 28 days
Acute pyelonephritis Ciprofloxacin 500mg bd for 7 days
Review treatment when urine culture results available. Admit to hospital if no response to antibiotics within 24 hrs.
Co-amoxiclav 500/125mg tds for 14 days
In pregnancy: Cefalexin 500mg bd for 10–14 days
Uncomplicated lower UTI Trimethoprim 200mg bd for 3 days in women (5–10 days if renal impairment, abnormal urinary tract or immunosuppression) and 7 days in men or indwelling catheter
Follow local antibiotic policies. Review treatment when urine culture results available. Nitrofurantoin is preferred to trimethoprim in recurrent infection. Treatment may be delayed in non-pregnant, non-catheterised women with mild symptoms, no visible haematuria, and normal immunity, renal function and renal tract.
Nitrofurantoin 50mg qds (or 100mg modified-release bd) for 3 days in women, 7 days in men or indwelling catheter
In pregnancy: Nitrofurantoin or trimethoprim as above but for 7 days, or cefalexin 500mg bd or 250mg qds for 7 days

Treatment options and adult dosages derived from NICE CKS, HPA Management of Infection Guidance for Primary Care for Consultation and Local Adaptation 2013 and/or SPCs [all accessed: May 2014].

Key:
od= once daily, bd= twice daily, tds= three times daily, qds= four times daily, stat= at once.

 



Read these next

Dequalinium chloride: new topical treatment for bacterial vaginosis

Dequalinium chloride: new topical treatment for bacterial vaginosis

Fluomizin (dequalinium chloride) is a new option for...

Updated MIMS summary of H. pylori treatment regimens

Updated MIMS summary of H. pylori treatment regimens

The popular quick-reference MIMS summary of NICE guidance...