Dexamethasone phosphate Intravenous for Adults

Who can administer

May be administered by registered competent doctor or nurse/midwife

Important information

  • Different brands have different compatibility information
  • Dexamethasone is incompatible with many drugs - flush thoroughly before and after administration
  • Dexamethasone phosphate injection contains 8mg in 2ml injection. This is equivalent to 6.6mg in 2ml of dexamethasone base. Prescribing practice in GUH has been to prescribe intravenous doses in terms of dexamethasone phosphate. The BNF now suggests that doses be prescribed as base. This monograph will be amended to reflect this once prescribing practice changes within the hospital.
  • Where supply restricts our choice of formulation pharmacy may have no choice but to use a formulation containing creatinine, which may interfere with the serum creatinine assay

Available preparations

Dexamethasone phosphate 8mg per 2ml vial

(equivalent to 6.6mg dexamethasone BASE per 2ml)


Already in solution

If glass ampoule: Draw up using a 5 micron filter needle

Infusion fluids

Sodium chloride 0.9% or Glucose 5%

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

  • Administer over at least 3 to 5 minutes (ref 1)
  • Rapid intravenous administration of large doses may cause cardiovascular collapse
  • IV administration can cause transient tingling/burning in perianal area, especially with rapid administration or with large doses

Intermittent intravenous infusion

  • Add required dose to 100mls of infusion fluid.
  • Administer over 15 to 20 minutes (ref 1)
  • A 50ml infusion may be used if required (eg fluid restriction) but the residual volume in the infusion line must be flushed through at the same rate to avoid significant underdosing
  • IV administration can cause transient tingling/burning in perianal area, especially with rapid administration or with large doses

Dose in adults

Dose varies widely with indication (ref 2)

  • Doses are expressed as Dexamethasone phosphate (see 'Important information')
  • Depending on the indication, the doses ranges from 0.5 to 24 mg daily
  • The duration of treatment depends on clinical response
  • Dose should be adjusted to the minimum required to maintain the desired clinical response
  • Withdrawal of the drug should be gradual following prolonged dosage, and other factors- see BNF
  • Up to 40mg daily for four-day treatment blocks may be given (see specific GUH multiple myeloma protocols) but usually given orally for this indication
  • Higher doses have been used for severe life-threatening cerebral oedema (50mg stat, then 8mg every two hours for three days, then reduced thereafter) (ref 2)

Bacterial meningitis (unlicensed) (ref 3)

  • Consider giving dexamethasone IV 0.15mg/kg every 6 hours for four days (particularly if pneumococcal meningitis suspected in adults), preferably starting before or with first dose of antibiotic, but no later than 24 hours after starting antibiotic
  • Avoid dexamethasone in septic shock, meningococcal septicaemia, or if immunocompromised, or in meningitis following surgery
  • CAUTION: only give if you are confident that the correct antibacterials are being used (see GUH antimicrobial guidelines or for the adult guidelines)


  • Store below 250C
  • Do not refrigerate or freeze


Wockhardt SPC 09/03/2017

1: Injectable Medicines Administration Guide Medusa, downloaded 07/01/2022

2: Martindale - downloaded from 07/01/2022

3: GUH antimicrobial guidelines accessed online 07/01/2022

Therapeutic classification


IV Guide Type