(Note: In diabetes, an expert physician’s services are invaluable and indispensable to determine the types of medicines and their dosage. In this respect, no article or book can ever take the place of the physician. The purpose of this chapter is only to provide a general overview of medicines used in diabetes.)
Two types of medicines are used in diabetes:
- Oral antidiabetic (hypoglycemic) drugs and
- Insulin, which is to be administered by an injection.
Oral hypoglycemic drugs : These drugs have been in use for last 30 – 35 years and are useful to almost half of all diabetics. They have no resemblance whatsoever to insulin. Oral hypoglycemic drugs are of two types:
- Sulphonylurea group of drugs
Sulphonylurea drugs stimulate the beta cells of the pancreas to produce more insulin. Besides they also prevent glucose present in the liver from entering the blood stream.
Biguanides increase the utilisation (though unnaturally) of glucose present in the blood by peripheral muscles.
In short, both these drugs strive to decrease the bloodglucose concentrations.
Side-effects of oral drugs include hypoglycemia, nausea vomitting, diarrhoea, liver disorders, jaundice, blood disorders and ketosis.
Oral hypoglycemic drugs are indicated in :
- Stable and maturity onset type of diabetes of recent onset which cannot be controlled on diet alone.
- Where the insulin requirement is upto 40 units.
- Diabetics who are not ketotic, i.e., whose blood has not been poisoned by the products of incomplete metabolism of fats.
- Diabetics with visual, neurological or psychic defects who cannot take insulin injections by themselves.
Oral hypoglycemic drugs are useless in :
- Unstable and thin diabetics
- Juvenile diabetics
- Diabetics who are prone to ketoacidosis
- Acute complications of diabetes
- Febrile (body-temperature raising) infections
Physically stressful conditions like a heart attack, cerebral haemorrhage, etc.
Insulin : Diabetes is a disease which arises due to a relative or absolute deficiency of insulin. ‘Diabetics should be benefitted by giving them insulin from outside’, so thought scientists and rightly so. Vigorous attempts to procure insulin from animals followed. Finally, in 1921 AD, Banting and Best succeeded in isolating pure insulin from the extract of animal pancreas. For this contribution to the treatment of diabetes, the names of Banting and Best shall be written in letters of gold.
Insulin revolutionised the treatment of diabetes. It robbed the disease of its fatality. At one time almost all child diabetics and many adult diabetics succumbed to diabetic coma. Insulin has provided a fresh lease of life to such diabetics. In the treatment of diabetes, the place of insulin is unique.
Like the insulin produced in a person’s body, externally given insulin too brings down the level of blood-glucose.
To whom and when is insulin useful or essential?
- Insulin should be used without delay in acute ketoacidosis and diabetic coma.
- For all juvenile diabetics, who cannot manufacture insulin in their own bodies, external insulin is a must.
- Insulin is essential for lean diabetics.
- For pregnant diabetic women, insulin is indispensable. They cannot be given oral antidiabetic drugs.
- Insulin is essential for those diabetics who have contracted febrile infections.
- Insulin is essential for persons suffering from complications of diabetes.
- Insulin is indispensable for the control of diabetes prior to or during a surgery on the diabetic.
- Insulin is indispensable in pancreatic diabetes.
- Insulin is useful to those women in whom itching on and around the genitals cannot be cured by any other measure.
Lente and N. P. H. insulins are much more commonly used and popular than other varieties of insulin. Generally a single injection of Lente insulin everyday is sufficient to control the blood-sugar of almost 60-70 percent of diabetics. This injection is to be administered by the patient himself, 20-30 minutes before the morning breakfast.
Previously, the tradition of mixing a short acting (e.g., crystalline) with an intermediate acting (e.g., N. P. H.) insulin was in vogue. But with the invention of Lente insulin, this practice is rapidly waning.
Rapidly acting varieties of insulin are presently used mainly in emergency conditions (e.g., diabetic coma), where the well-being or life of the patient is at stake.
Monocomponent Insulin : Commonly used insulins possess impurities like proinsulin, desamido insulin, glucagon, pancreatic polypeptide and somatostatin in minute amounts. By chromatographic purification techniques, scientists have succeeded in getting rid of such impurities and manufacturing extremely pure ‘monocomponent insulin’, Such pure insulin is naturally very effective.
Uses of monocomponent insulin :
- When common insulin gives rise to an allergic reaction.
- When insulin is required only for short duration, (e.g., during pregnancy or surgery).
- When due to resistance developed inside the body, the requirement of common insulin exceeds 100 units per day.
- When commonly used insulin gives rise to destruction of fat-cells beneath the skin (lipodystrophy).
Semisynthetic human-insulin : In 1978, scientists succeeded in manufacting semisynthetic human-insulin by ‘recombinant D.N.A. technique’. In this method, the human gene responsible for the manufacture of insulin are tranplanted into the bodies of bacteria called ‘E Coli’. Thereafter, these bacteria start manufacturing an insulin which is fastacting and exactly similar to human-insulin. Such insulin can be used for very strict vegetarians too. This ‘human-insulin’, however, has been observed to excite a response of resistance or allergy in certain patients.
At present, such human-insulin is available in Denmark and other western countries.
The dosage of insulin : The task of determining the ideal dosage of insulin for a particular patient is very complicated and should be left alone to the physician. An ideal dosage of insulin is the one which continuously maintains the bloodsugar level within normal limits. Some patients require as low a dose as 10-12 units per day. Others require 100 units or even more insulin everyday. On an average 30 to 40 units of insulin, has been found an effective dose.
To a diabetic, who has no other complication, most doctors usually first give 20 units of Lente insulin per day. Three to four days after commencing the treatment, urine samples, obtained during the course of the day, are analysed for sugar. Depending upon the absence or presence of sugar in the urine, the insulin dosage is decreased or increased, respectively.
Once the ideal dose of insulin has been determined, the patient should follow that dosage faithfully and should make no changes in the dosage on his own.
Factors that can necessitate a change in the insulin dosage:
If one of the above conditions arises, a change in the insulin dosage is required. However, the degree of the essential change can be determined only by a physician.
Method of taking insulin injection : It is not only desirable but extremely essential that every diabetic learns to inject insulin in his body himself. A person who solely relies upon his doctor (or a member of his family) for insulin injections may find himself in difficulty if he or his physician is on a tour. In fact, injecting insulin on one’s self is an extremely simple procedure.
- Syringe : 2 c.c. syringe, preferably of glass. Each c.c. must be divided into 10 parts. 1/10 c.c. =4 units if 1 c.c. insulin contains 40 units. 1/10 c.c.=8 units if 1 c.c. insulin contains 80 units.
- Needles : A long and stout needle to draw insulin from the bottle. A small (1.25 cms) and thin (no. 25 or 26) needle for insertion into the body.
- Spirit (or some other antiseptic) : To cleanse the skin and the cap of the insulin-bottle.
- Clean cotton
- Insulin bottle : The strength of the insulin should first be ascertained from the label to avoid difficulty. In the market, insulin is available in varying strengths, mainly 40 units/c.c. and 80 units/ c.c.
- Forceps: To lift the syringe or the needle lying in boiling water (it is necessary to sterilise the syringe and the needle by boiling them prior to their use). It is a general practice to keep the used needles or syringes immersed in alcohol.
Steps to effect an injection:
- First of all, roll the insulin vial (bottle) between the palms for a minute or two to render the contents homogeneous.
- Clean the rubber-cap of the bottle with spirit.
- Lift the syringe out of the boiling water, with the forceps. Transfer the syringe to the left hand. Lift the long needle out of the boiling water and fix it to the syringe.
- Draw the piston out of the syringe to such an extent that an air-filled space, whose volume is equal to the amount of insulin to be injected, is created.
- Insert the needle into the insulin bottle through the rubber cap and empty the air present in the syringe into the bottle.
- Invert the bottle and draw into the syringe, insulin whose amount is slightly greater than actually required.
- Very slowly push the piston upwards to drive out air bubbles and the extra insulin from the syringe. If while doing so more than the desired amount of insulin is driven back into the bottle, again draw the required amount. Finally, remove the needle out of the bottle.
- Continue to hold the syringe upside down. Remove the long needle from the syringe and replace it by the small needle, lifted from the boiling water with the forceps.
- The sites of the body, suitable for injections have been depicted below. Cleanse the skin of the selected site with spirit and lift the skin (and the underlying muscles) by pinching it with fingers.
- Steadily and firmly insert the needle beneath the skin, almost vertically downwards, till about 2/3 of the needle has penetrated inside the body.
- Press the piston to completely release the insulin into the body.
- Finally withdraw the needle from the body and gently massage the punctured part of the skin with cotton soaked in spirit.
- It is extremely important to change the site of injection everyday. Injecting insulin into the same part of the body day after day causes great problems which have been described later.
- Every diabetic should keep at his home, one or two extra syringes and needles, so that a situation, where the treatment has to be delayed or suspended, does not arise.
- It is also desirable to store (preferably in a refrigerator) some extra bottles of insulin.
- Disposable (which can be discarded after a single usage) syringes and needles are available in the market. Affording persons can use them with some advantage.
- It is desirable that a family-member of the diabetic, too, learns the art of injecting insulin. This skill comes handy when the diabetic is unconscious or incapacitated by some illness.
- For those diabetics who fear the needle excessively, needleless syringes or guns are available in big cities. After filling such a gun with the required amount of insulin, a high pressure is built up inside. The gun is then held in contact of diabetic’s skin and the trigger of the gun released. Insulin released with great force and speed, pierces the skin and enters the body.
Special Note : Injecting insulin is a somewhat labourious procedure. Besides, one or two injections of insulin every day may not succeed in maintaining the blood-sugar levels within normal limits throughout the day. In normal circumstances, slight fluctuations of blood-sugar levels may be inconsequential. But in critical situations, like diabetic coma, a stricter control of blood-sugar level is desirable.
To serve this purpose, such instruments have been developed which imitate the human pancreas. The working of a large instrument, commonly used in hospitals, is quite simple. A tube (of the machine) continuously draws blood from the patient’s body and sends it to the instrument, where the blood is continuously analysed for its glucose-content. Then as per the requirements, either insulin or glucagon is released into the patient’s body. This instrument is, however, too large and cumbersome. It cannot be used outside the hospital or cannot keep the patient ambulent. In fact, at present it is used only to tide over a critical phase, i.e., for a day or two.
Efforts have also been made to develop much smaller instruments that a diabetic can wear on his body and continue his day to day activities. One such instrument, available in western countries, needs to be worn on the waist belt. The needle of this instrument remains pierced into the patient’s body. This instrument has no glucose-sensor to analyse blood-glucose level. Some insulin continuously enters the patient’s body. After a snack or a meal, the patient has to compress an elastic pump present on the instrument, to release additional quota of insulin, commensurate to the need.
The idea of developing an instrument which could be transplanted beneath the skin and which would work exactly like human pancreas is being actively pursued.
The sensor present in this gadget will continuously evaluate the glucose level of the blood. Thereafter insulin from the glucose reservoir of the gadget will be continuously released into the body as per the need. Such gadget is likely to be available in the near future.
Side-effects of insulin :
(1) Unconsciousness may occur due to blood-glucose level falling much below the physiological limit (i.e., 50 mg %). Such unconsciousness is termed ‘hypoglycemic coma’.
The symptoms that precede unconsciousness include excessive fatigue and weakness, hunger, headache, giddiness, cold sweating, etc. If not treated immediately, the patient falls unconscious.
Such a situation may arise in a diabetic’s life any time. It is precisely for this reason that every diabetic should always keep in his pocket a card, as depicted below:
(2) Allergic response (of the body) may arise against insulin (especially protamine zinc insulin). This allergy is manifested by red coloured rashes on the skin or swelling.
(3) About 25 to 35 percent of child diabetics suffer from lipodystrophy, i.e., fat cells beneath the skin at the site of injections may get destroyed. This gives an extremely unsightly and grotesque appearance to the skin.
(4) The cells of the body at and around the site of insulin injections may die and rot (insulin necrosis).
This brings an end to the discussion on oral antidiabetic drugs and injectable insulin, used to control diabetes. Oral drugs and insulin can be used independently or in conjunction.
Ayurveda, too, has recommended many a drug or herb to combat diabetes. These include leaves of madhnashi(gudmar), roots of tondli (tindora) and sadaphuli, extracts of onion and garlic, concoction of neem leaves, karela juice, powdered jamun seeds, shilajit and jasad bhasma. Of these, karela juice, shilajit, jasad bhasma and powdered jamun seeds have been seen to have a slight beneficial effect in some cases. It should, however, be noted that jamun fruits are rich (15%) in sugar and are prohibited for diabetics.
Homoeopathy recommends Acid phosphoric, Metallic silver and Sulphate of soda for diabetes. But all these drugs have proved worthless in controlled clinical trials.
In fact, after the invention of powerful sulphonylurea and biguanide drugs, all indigenous and homoeopathic drugs are fast waning from the limelight.