(15) Diabetes
Insulin pens
What is an insulin pen, and what are the advantages of using one?
An insulin pen consists of a cartridge of insulin inside a fountain pen type case which is used with a special disposable needle.
After dialling the required number of units of insulin you need and inserting the needle into the skin, you press a button and the pen will release the correct dose of insulin.
Several makes of pen are available and your specialist nurse or doctor will show you the current models. They may be used with any of the cartridges.
Novopens are supplied by Novo Nordisk, HumaPen by Eli Lilly, OptiPen by Aventis Pharma and Autopens by Owen Mumford (Medical Shop). Insulin pens are now available on prescription except for the Humapen and the Optipen. They should be available free of charge from your diabetes clinic.
Insulin cartridges and the pen needles for all these pens can be prescribed by your doctor.
Preloaded pens, also called disposable pens, which contain 300 units of insulin, are obtainable on prescription. They are available with most or part of NovoNordisk, Eli Lilly and Aventis Pharma insulin range.
People wishing to continue to use animal insulin in a pen can do so by using Hypurin neutral, Hypurin isophane or Hypurin 30/70 mix cartridges manufactured by CP Pharmaceuticals. These cartridges are recommended for use with the Owen Mumford Autopen.
The great advantage of insulin pens is convenience and ease of use. It is simple to give an injection away from home, e.g. in a restaurant or when travelling. If you are visually impaired, or if you suffer from arthritis in your hands, then you may find the dial-a-dose clicking action is easier to use than drawing up insulin in a conventional syringe.
All these pens rely on ordinary finger pressure for the injection, i.e. they are not automatic injectors. If you are afraid of needles, finding it difficult to inject your insulin but still would like to use a pen, Novo Nordisk have introduced the Penmate which hides the needle from view when the injection is given.
What is the advantage of taking four injections a day with an insulin pen?
The idea of using a multiple injection regimen is to try to mimic the normal secretion of the pancreas by giving small doses of short-acting insulin to cover meals and longer-acting insulin at bedtime to act as background insulin. This system should really be called basal + bolus, i.e. long acting ‘basal’ insulin at night with a ‘bolus’ of short-acting insulin before each meal. It is more convenient to implement with the use of an insulin pen.
Some people who lead rather erratic lives find the insulin pen regimen more convenient. They have a little more flexibility over the timing of their meals, as the insulin is not taken until just before the meal is eaten. In practice they may also need some longer-acting insulin taken in the morning to act as background insulin. Another advantage of using an insulin pen is that bottles of insulin do not need to be carried around during the day, and it is easier to give an injection discreetly.
