Amoxicillin Intravenous for Adults

Who can administer

May be administered by registered competent doctor or nurse/midwife

Important information

  • Penicillin antibiotic
  • See under 'Dose' for adjustments required in renal impairment

Available preparations

Clamoxyl or Amoxil 500mg vial (ref 1)

Amoxicillin 1g vial (Wockhardt) (unlicensed)


Water for injection

10ml per 500mg vial

20ml per 1g vial 

The dilution may be carried out in a syringe as the full 10ml will not fit into the vial

Infusion fluids

Sodium chloride 0.9%

Methods of intravenous administration

Can use either method of administration- choice depends on practicalities such as time available, fluid status of patient, etc.

Slow intravenous injection (doses up to 1g) (ref 2)

  • Administer over 3 to 4 minutes

Intermittent intravenous infusion: (all doses)

  • Add the dose to 100ml and administer over 30 to 60 minutes  (ref 2)


Dose in adults

Mild or moderate infections (BNF)

  • Give 500mg every eight hours 

Community acquired pneumonia (ref 1)

  • Give 1g every eight hours
  • Given in combination with other drugs

Severe infections (BNF)

  • Give 1g every six hours 

Listerial meningitis (BNF)

  • Give 2g every four hours 
  • Given in combination with other drugs 

Endocarditis (BNF)

  • Give 2g every four hours 
  • Given in combination with other drugs

Renal impairment (ref 3)

eGFR  (ml per minute/1.73m2) Dose
Greater than 10 No adjustment necessary
less than 10

250mg to 1g every eight hours. 

High dose regimens eg endocarditis and listeria meningitis: maximum 2g every eight hours

Renal replacement therapy Consult pharmacy or specialist information sources 


Store below 25° C



SPC April 2018
(1) Email on file from GSK- Clamoxyl is interchangeable with Amoxil

(2) Injectable Medicines Guide - Medusa. Accessed online 25/11/2021
(3) GUH antimicrobial guidelines 

(4) Amoxicillin 500mg SPC accessed 16/12/21

Therapeutic classification

Broad-spectrum penicillin