Intravenous to oral switch for high-severity CAP in adults

For adults with high-severity CAP who started with intravenous therapy, switch to oral or enteral therapy once the patient has improved and is clinically stable (see Guidance for intravenous to oral switch for guidance on when to switch to oral therapy).

Note: Do not use amoxicillin+clavulanate for intravenous to oral switch.

Amoxicillin+clavulanate is not an appropriate choice for intravenous to oral switch for adults with high-severity CAP. Compared with amoxicillin+clavulanate:

amoxicillin is less selective for resistance
amoxicillin has fewer adverse effects
at the dosage recommended for CAP (1 g orally, 8-hourly), the concentration of amoxicillin is significantly higher (which is needed in case of infection due to Streptococcus pneumoniae with a higher minimum inhibitory concentration [MIC] to penicillin).

For intravenous to oral switch in adults with high-severity CAP, if a pathogen is not identified, as a 2-drug regimen, use:

amoxicillin 1 g orally or enterally, 8-hourly. For dosage adjustment in adults with kidney impairment, see amoxicillin dosage adjustment. See advice on patient review and duration of therapy amoxicillin amoxicillin amoxicillin

PLUS (unless the patient has had at least 3 days of intravenous azithromycin)

azithromycin 500 mg orally or enterally, daily; see advice on patient review and duration of therapy. azithromycin azithromycin azithromycin

For adults with high-severity CAP who have already had 3 days of azithromycin, use amoxicillin monotherapy (at the dosage above).

For adults with high-severity CAP who have nonsevere (immediate or delayed) penicillin hypersensitivity, or severe immediate¹ penicillin hypersensitivity who tolerated ceftriaxone², replace amoxicillin in the above regimen with:

cefuroxime 500 mg orally or enterally, 12-hourly. For dosage adjustment in adults with kidney impairment, see cefuroxime dosage adjustment. See advice on patient review and duration of therapy ³. cefuroxime cefuroxime cefuroxime

For adults with high-severity CAP who have severe immediate¹ penicillin hypersensitivity in whom ceftriaxone was not used nor tolerated, or for patients with severe delayed⁴ penicillin hypersensitivity, as monotherapy, use:

moxifloxacin 400 mg orally or enterally, daily. For dosage adjustment in adults with kidney impairment, see moxifloxacin dosage adjustment. See advice on patient review and duration of therapy. moxifloxacin moxifloxacin moxifloxacin

¹ Severe immediate hypersensitivity reactions include anaphylaxis, compromised airway, airway angioedema, hypotension and collapse.Return

² For patients with severe immediate penicillin hypersensitivity who tolerated initial intravenous therapy with ceftriaxone, it is safe to use cefuroxime.Return

³ Cefuroxime is preferred to cefalexin or cefaclor because of its superior antipneumococcal activity; see Practical information on using beta lactams: cephalosporins for further information.Return

⁴ Severe delayed hypersensitivity reactions include cutaneous adverse drug reactions (eg drug rash with eosinophilia and systemic symptoms [DRESS], Stevens–Johnson syndrome/toxic epidermal necrolysis [SJS/TEN], severe blistering or desquamative rash), and significant internal organ involvement (eg acute interstitial nephritis).Return