Sodium nitroprusside Intravenous for Adults

Who can administer

Administration RESTRICTED - see Appendix 1

Important information

  • Flush: Do not flush the administration set. After the infusion is discontinued, disconnect the giving set, aspirate the catheter contents and flush the cannula/catheter with sodium chloride or glucose 5% (ref 4,5)
  • Consider cyanide toxicity if patients with hepatic or renal impairment, or in rates exceeding 3 micrograms/kg/minute for more than 72 hours (ref 1)
  • Unlicensed preparation
  • Sodium nitroprusside produces an immediate response of short duration; within a few (1 to 10) minutes of discontinuation of the infusion, the patient's blood pressure returns to initial levels
  • For Y-site compatibility see below

Available preparations

Sodium Nitroprusside 50mg per 2ml vial (Sandoz brand)- with solvent ampoule provided

Reconstitution

Dilute the contents of the vial using the solvent ampoule provided

Draw up solvent ampoule using a 5 micron filter needle

Dilute further prior to administration

Infusion fluids

Glucose 5% only

Methods of intravenous administration

Continuous intravenous infusion (administer using an electronically controlled infusion device)

  • Add 50mg to 250ml infusion fluid (200 micrograms/ml) (ref 6)
  • The infusion device, and the giving set must be covered to protect the drug from light - silver wrapping is provided in the pack to allow this
  • Administer at a suitable rate as per 'dose' below
  • The prepared solution has a very faint brownish tint - if it is highly coloured it should be discarded
  • Fluid restriction: can prepare a 1mg per 1ml solution (central line only) (ref 3,4)

Dose in adults

Using a 50mg in 250ml strength
Dose in micrograms/kg/minute 0.1 0.3 0.5 1 1.5 2 2.5 3 3.5 4 5 6 7 8
Weight in kg (below) Rate below is in ml per hour
40kg 1.2 3.6 6 12 18 24 30 36 42 48 60 72 84 96
45kg 1.4 4.1 6.8 13.5 20.3 27 33.8 40.5 47.3 54 67.5 81 94.5 108
50kg 1.5 4.5 7.5 15 22.5 30 37.5 45 52.5 60 75 90 105 120
55kg 1.7 5 8.3 16.5 24.8 33 41.3 49.5 57.8 66 82.5 99 115.5 132
60kg 1.8 5.4 9 18 27 36 45 54 63 72 90 108 126 144
65kg 2 5.9 9.8 19.5 29.3 39 48.8 58.5 68.3 78 97.5 117 136.5 156
70kg 2.1 6.3 10.5 21 31.5 42 52.5 63 73.5 84 105 126 147 168
75kg 2.3 6.8 11.3 22.5 33.8 45 56.3 67.5 78.8 90 112.5 135 157.5 180
80kg 2.4 7.2 12 24 36 48 60 72 84 96 120 144 168 192
85kg 2.6 7.7 12.8 25.5 38.3 51 63.8 76.5 89.3 102 127.5 153 178.5 204
90kg 2.7 8.1 13.5 27 40.5 54 67.5 81 94.5 108 135 162 189 216
95kg 2.9 8.6 14.3 28.5 42.8 57 71.3 85.5 99.8 114 142.5 171 199.5 228
100kg 3 9 15 30 45 60 75 90 105 120 150 180 210 240
105kg 3.2 9.5 15.8 31.5 47.3 63 78.8 94.5 110.3 126 157.5 189 220.5 252
110kg 3.3 9.9 16.5 33 49.5 66 82.5 99 115.5 132 165 198 231 264
115kg 3.5 10.4 17.3 34.5 51.8 69 86.3 103.5 120.8 138 172.5 207 241.5 276
120kg 3.6 10.8 18 36 54 72 90 108 126 144 180 216 252 288

Hypertensive crisis (doses are in micrograms/kg/minute)

  • Initial dose is normally within the range of 0.5 to 1.5 micrograms/kg/minute, lower initial doses of 0.3 to 0.5 micrograms/kg/minute have also been used (ref 1,2,7)
  • This can be adjusted in increments of 0.5 micrograms/kg/minute every three to five minutes (ref 6)
  • Dose range 0.5 to 8 micrograms/kg/minute (average dose required 3 micrograms/kg/minute
  • Higher doses up to 10 microgram/kg/minute may be needed for a maximum time of 10 minutes (ref 1)
  • Action occurs within 1 to 2 minutes (ref 6)
  • Excessive hypotension resulting in compromised perfusion of vital organs must be avoided (ref 1)

Heart failure (doses are in micrograms/minute)

  • Initial dose should be between 10 to 15 micrograms/minute, increased every 5 to 10 minutes to the normal range of 10 to 200 micrograms/minute, to obtain the desired response
  • Usually for maximum of three days for this indication (ref 7)

Controlled hypotension during general anaesthesia (doses are in micrograms/kg/minute)

  • Maximum dose of 1.5 microgram/kg/minute is recommended (ref 2,7)

Monitoring

  • Monitor patients for signs of cyanide toxicity - which may present as symptoms of hypothyroidism

Storage

  • Store below 250C
  • Following reconstitution, protect the bag from light by covering with aluminium foil (supplied with product) or other opaque material as soon as possible. Under these conditions the 50mg in 250ml glucose 5% infusion is stable for 24 hours (ref 5). Discard the bag if the solution develops a strong discolouration (a faint brown tint is acceptable to use).

References

SPC Sandoz brand Nitroprussiat Fides 50mg/2ml (PIL May 2017)

(1) Uptodate accessed online 22/10/2021

(2) Martindale accessed online 21/10/2021

(3) Minimum infusion volumes UKCPA version 4.4 December 2012

(4) Injectable Medicines Guide, Medusa accessed online 21/10/2021

(5) Injectable Medicines Administration Guide UCL Hospitals 3rd ed

(6) American Heart Association ACLS core drugs 2006

(7) BNF online accessed 16/11/2021

Therapeutic classification

Vasodilator antihypertensive