Humalog[R]--an accident waiting to happen: three different Humalog[R] preparations are now available for the treatment of type 1 and type 2 diabetes. Nurses must be vigilant when administering these medications.Insulin is a high-risk drug, subject to errors in prescribing, dispensing and administration, with potential to harm patients.
Human insulin preparations are routinely used to treat type 1 diabetes and are increasingly used to treat type 2 diabetes, when blood glucose cannot be controlled with oral antihyperglycaemic medicines. One of the main issues when treating insulin-dependent diabetics is the timing of insulin injections in relation to meats, in order to limit hyper and hypogtycaemia.
Humalog[R] insulin has been available for some time but the recent introduction of two new Humalog[R] insulin preparations--Humalog mix[R] 25 and Humalog mix[R] 50--has resulted in multiple errors in New Zealand. These preparations differ in their pharmacokinetic profiles.
There are now three Humalog[R] insulin preparations:
* Humalog[R]--a rapid acting insulin
* Humalog Mix[R] 25--a mixture of rapid and intermediate acting insulin
* Humalog Mix[R] 50--a mixture of rapid and intermediate acting insulin
The potential for serious harm is high if a patient receives or is given the wrong preparation of Humalog[R], especially if the rapid acting plain Humalog[R] is given, instead of the rapid intermediate acting Humalog Mix[R] products.
Errors have been reported where:
* the wrong product has been selected from a drop-down menu in electronic dispensing systems;
* a patient said they used Humalog[R] 25 bd and was prescribed Humalog[R] 25 units bd, when the patient was actually on Humalog Mix[R] 25; and
* Humalog Mix[R] 25 or 50 has been prescribed, but Humalog[R] has been administered
The intention of this report is to highlight the risk with the new Humalog[R] products.
Extra care needed
As nurses are involved in the administration of insulin, it is vital they understand the differences and take extra care in the administration of these products. The main differences between the preparations are onset and duration of action. This means administration of the wrong product will produce and alter effects related to the utilisation of insulin.
Humalog[R] (insulin lispro injection) is a new rapid acting insulin. A small structural difference from regular human insulin allows it to start working more rapidly as a blood glucose lowering agent because it is absorbed from subcutaneous tissue more rapidly. It can be given 15 minutes before a meat, with a peak effect about an hour tater, and the duration of action is between 3.5 and 4.5 hours. As with art insulin, there is considerable inter-individual variation in the way insulin is absorbed, distributed and metabotised.
Humalog Mix[R] 25 (75 percent insulin lispro protamine suspension and 25 percent insulin lispro injection) is a mixture of insulin lispro solution (Humalog[R]), that acts rapidly with insulin lispro protamine suspension, an intermediate acting, blood glucose towering agent. The peak effect of Humalog Mix[R] 25 is usually around an hour after injection. The duration of action of insulin lispro protamine suspension is between 16 and 18 hours.
Humalog Mix[R] 50/50 (50 percent insulin lispro protamine suspension and 50 percent insulin lispro injection) has two phases of absorption. The early phase represents insulin lispro and its distinct characteristic of rapid onset. The late phase represents the prolonged action of insulin lispro protamine suspension. The peak effect is usually about two hours after injection, with the duration of action between 16 and 18 hours.
To ensure insulin therapy is effective, appropriate and safe, nurses must be vigilant in administering the drug, taking into consideration that different formulations have different onset and duration of effects.
Reducing/preventing administration errors
* Be aware there are now three Humalog[R] preparations.
* All insulin should be prescribed using the full brand name--if this isn't the case, ask the prescriber to clarify the order.
* Check with the patient about which sort of insulin preparation they are on, eg not only the brand but also a description of the type-rapid, intermediate or tong acting. This acts as an extra check.
* Always double check which insulin the patient is prescribed against the vial, to ensure they match.
* Inform the patient about the risk of errors, so they are fully informed about which Humalog[R] insulin preparation they are on and the importance of describing it accurately.
* Ensure the products are labelled correctly.
* Increase awareness for potential errors with these products, by providing ongoing education to patients and staff.
An alert and poster have been issued by the District Health Board New Zealand's (DHBNZ) Safe and Quality Use of Medicines Group (SQM Group). These are available on www.safeuseof medicines.co.nz
Safety is one part of the quality use of medicines. To achieve the quality use of medicines, people must be provided with safe, effective and appropriate treatment and have the knowledge and skiffs to use medicines to both their best effect and safety.
The SQM Group comprises nurses, doctors and pharmacists and was established as a collaborative venture between DHBNZ and the chief executives group in May 2003.
The safe and quality use of medicines strategy, published in 2005, covers activities in both primary and secondary care. It has been designed to provide both a national framework and national co-ordination of activities to improve medicine-related outcomes. The strategy also aims to encourage consistency, effectiveness and participation in the safe and quality use of medicines, white reducing duplication.
For more information about DHBNZ's SQM Group, please go to its website on www.safeuseofmedicines.co.nz or contact the national co-ordinator of SQM Group, Beth Loe, on 09 486 8920, ext. 2442.
By DHBNZ Safe and Quality Use of Medicines Groups