Initiation
of Insulin
There are no precise formulae by which the initial dose can be
calculated. The usual total dose of insulin is between 0.5 and
1 unit/kg/day although it is usual to start with a starting dose
of 0.25 unit/kg/day.
The usual regimen is to start with a small dose of an intermediate
acting insulin about 8-12 units S.C. before breakfast or with
a mixture of a short acting insulin and Intermediate acting insulin
in small doses.
When stabilized most patients require about 60% of total insulin
in the morning and 40% in the evening. However insulin-dosing
regimen is highly individualized and it has to be tailor made
depending upon the patient’s age, weight, sugar levels and
presence of any other condition, which may affect the status of
blood sugars.
Often overweight patients may need more insulin due to insulin
resistance.
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Most of the short acting and the intermediate/long acting insulins
available here may be mixed in the same syringe except Lantus.
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Insulins are presently available in strengths of U-40, and U-100.
The patient must ensure that the syringes used by him/her are
compatible with the strength of insulin used.
Insulin Delivery
The various methods of insulin delivery are by injections, insulin
pens, and insulin pumps and lately by inhalation (EXUBERA). The
inhaled insulin is in the last phase of clinical trial in USA
and is expected to be available in the market by next year.
1)
Injection. The needle and syringe is the commonest
of the four insulin delivery systems. Today's needles are much
improved from years ago. They are sharper, finer, and coated with
Teflon to make injections much less painful than they used to
be.
Injections should be given preferably 20-30 minutes before the
meal to achieve proper peak of insulin action corresponding to
elevated sugar levels after a meal except Lantus which can be
given just before the meals. The needle is to be inserted in the
pinched up skin at 90o angle so that the injection is in the subcutaneous
tissue. It is advisable to use disposable syringes, which are
now easily available.
The cost of the syringe is often a limiting factor to the routine
use of these syringes. Patients can reuse the same disposable
syringe and decrease the costs. Insulin syringes may be reused
2-3 times if the needle is not blunt. The same syringe can be
used for different sites but it should never be used on different
patients.
2)
Insulin pens. An insulin pen is a compact, portable
device that serves exactly the same function as a needle and syringe,
but is handier and more convenient to use. A wide variety of disposable
and reusable insulin pens that come pre-loaded with their insulins
are available in the market.
One of the great advantages of insulin pens is that they are more
suitable for patients who are frequent travelers.
3)
Insulin pump. An insulin pump is a computer-controlled
device, which comes in the size and shape of a pager. It painlessly
and accurately delivers insulin all day long through a tiny tube
inserted just under the skin.
Insulin pump is the best and most intensive way that currently
exists to control diabetes. The pump is not entirely pain-free.
The location of the infusion set has to be changed after every
second or third day to prevent infection at the site.
Last
updated on 13-12-2002
