To:All Consultants, All Matrons, All Pharmacy, All Safety & Risk Management Board

Memo

To:All Consultants, All Matrons, All Pharmacy, All Safety & Risk Management Board

From:Matt Clarke, Medicines Information Manager RHH, 12346.

Date:11/12/2014

Dexamethasone injection – STHFT to keep the 3.8mg/mL (Aspen) preparation only

Further to the memo of 25/11/14 regarding the changes in formulation and brands of dexamethasone injection to be kept at STH, the Medicines Safety Committee has revised its decision.

STH will now only keep dexamethasone injection 3.8mg/mL (Aspen brand).

Please note that this formulation requires refrigerated storage.

The Aspen brand (3.8mg/mL) is licensed for IV, IM and SC injection and contains glycerol instead of propylene glycol as a solubilising agent. It is felt that glycerol is safer than propylene glycol when given to neonates andvia the intravitreal or spinal route in adults. The Aspen brandis virtually identical (excipient-wise) to the previously available Organon brand, which has been used and administered via these routes for years within the Trust.

Dosing

The dose of dexamethasone prescribed usually relates to dexamethasone base and familiarity with using 4mg/mL has resulted in doses prescribed in multiples of 4mg. A 4mg dose of the Aspen product is undeliverable as the volume required is 1.05mL

Administration of 1mL of the Aspen product will result in a dose of 3.8mg, a 5% underdose. However, given the huge range of doses used in clinical practice, and the fact that subsequent doses tend to be adjusted to reflect clinical response, it is unlikely that this would have major clinical consequences.

Nevertheless it is important to put in place measures to ensure that patients receive the intended dose prescribed.

See next page for specific advice for prescribers and nursing and pharmacy staff.

Advice to prescribers

Doses of dexamethasone injection should be prescribed in multiples of 3.8mg instead of multiples of 4mg.

Example

Previously prescribed dose

/ New amended dose / Volume of dexamethasone 3.8mg/mL
(Aspen)
4mg / 3.8mg / 1ml
8mg / 7.6mg / 2ml

Any guidelines/protocols in place that recommend doses in multiples of 4mg need to be amended to recommend doses of the available preparation however this has significant implications for Chemocare regimens at Weston Park (and hence surrounding hospitals).

Doses of 8mg and 20mg dexamethasone on Chemocare regimens can be given using the new formulation – on occasions where reduction of dose is required please contact pharmacy for advice.

Advice to nursing and pharmacy staff

Doses of dexamethasone injection prescribed in multiples of 4mg must be returned to a prescriber for amendment as above, unless the dose is part of a Chemocare regimen.

For doses as part of Chemocare regimen only:

Dexamethasone 8mg = 2.1ml of 3.8mg/ml injection

Dexamethasone 20mg = 5.2ml of 3.8mg/ml injection

On occasions where different doses are required please contact Pharmacy for advice.

Some areas have already been issued with the 6.6mg/mL (Hameln) preparation. This stock will be replaced by Pharmacy staff over the next few days.

Ward/clinical area profiles will also be updated by Pharmacy accordingly so that the new preparation will be automatically supplied on top-up.

Please contact Medicines Information if you require further advice or information

Medicines Information RHH office – Tel 12346

Medicines Information NGH office – Tel 14371