Diabetes | August 15, 2014 | Author: The Super Pharmacist
People with type 1 diabetes and some with type 2 diabetes must receive insulin delivery in order to process the sugars they eat. Unfortunately, insulin is not available in an oral medication because the acids and enzymes in the digestive system destroy it before it can be absorbed. Therefore, most people who require insulin must give themselves daily injections, sometimes multiple times a day. Fortunately, researchers are developing innovative devices that may eliminate the pain and hassle of insulin injections.
An insulin pump is a device that supplies insulin through a small tube placed under the skin. The small tube, called a catheter, is replaced every 2 to 3 days. The typical insulin pump will deliver both basal insulin and mealtime insulin. The basal insulin is a low dose of insulin administered more or less constantly throughout the day while mealtime insulin is a bolus meant to help process nutrients consumed during a meal.
The dose of insulin—especially mealtime insulin—still requires the patient to perform blood glucose testing with a finger stick. Insulin pumps are available for both type 1 and type 2 diabetes. Surprisingly, insulin pumps are no better than insulin injections at improving blood sugar control or reducing the number of times people experience hypoglycaemia. However, insulin pumps are far more convenient for children with diabetes and their families.
The goal of insulin pump research is to develop a closed loop insulin pump, sometimes called an artificial pancreas. A closed loop insulin pump is a device that measures glucose levels in the blood and delivers the appropriate amount of insulin automatically. As glucose levels go up, as it would after a meal, the artificial pancreas detects this increase and releases more insulin into the bloodstream. This device would virtually eliminate the need for finger stick blood glucose testing. These devices are not yet commercially available, but they are in clinical trials. Tests on an artificial pancreas showed that people enjoyed excellent blood glucose levels and had far fewer instances of nighttime hypoglycemia.
In September 2006, the FDA approved an inhalable, powdered insulin marketed under the name Exubera. The insulin was inhaled in the same way that a patient with asthma would use an inhaler. Exubera faced many challenges. It was difficult to predict the dose of insulin that patients were getting from the inhaler. Also, the cost of Exubera was substantially more than injectable insulin. Within a year, the manufacturer of Exubera pulled it from the market.
In June 2014, the FDA approved another inhaled form of insulin, brand name Afrezza, for people with type 1 and type 2 diabetes.
Afrezza is not for use by people who smoke or who have a chronic lung disease such as asthma or COPD. In fact, people who wish to use Afrezza must undergo pulmonary (lung) function tests.
It is unclear if Afrezza will be commercially successful. Clinical studies appear to be promising.
Blood sugar levels were controlled equally well with Afrezza and injectable insulin. Importantly, instances of hypoglycemia were less common for the people taking the inhaled insulin. Only time will tell if Afrezza is more successful than Exubera.
An insulin pen is an insulin injection device that eliminates the need for insulin vials and syringes. The user simply dials the desired number of insulin units on the end of the pen, and then delivers the insulin with a disposable needle attached to the end of the pen.
Insulin pens are available in two main types, refillable and prefilled disposable pens. Refillable pens carry the names HumaPen, Autopen, NovoPen, and OptiClik among others. Prefilled disposable pens include FlexPen, KwikPen, and SoloSTAR.
While the overall cost is higher, insulin pens have been clinically proven to be more accurate and easier to use. They also receive higher patient satisfaction ratings, quality-of-life ratings and people with diabetes tend to use insulin pens more regularly than the syringes.
Insulin pens may be particularly useful for children with type I diabetes who need low doses of insulin. When using a syringe, low insulin doses may be hard to draw from the vial accurately. When using an insulin pen, the child simply needs to know the number of units required and can dial the precise amount. Newer insulin pens appear to be significantly better than older versions. For example, newer versions require less force when performing injections and the electronics have also been updated.
Some pens include a memory function that will record the date, time, and amount of the insulin injected. This can be helpful for remembering insulin dosages and plotting insulin usage. The main drawback to insulin pens, besides a higher cost, is that patients cannot mix their own insulin combinations, so may require more injections daily.
Oral insulin is the 'Holy Grail' of diabetes therapy and still remains elusive. Current research is focused on protecting the insulin as it travels through the digestive system. Drug manufacturers are developing novel hydrogel capsules that protect the insulin from stomach acid and digestive enzymes until the capsule reaches the small intestine. A commercially available oral insulin medication is still years away.
The mouth is covered with a particular type of “skin” that allow certain drugs to penetrate and enter into the bloodstream directly. For example, any drug that is available in the dissolving form is absorbed into the buccal mucosa.
Drugs are able to enter the bloodstream rapidly and directly without being digested in the stomach or significantly metabolised by the liver - named “first pass metabolism”.
One of the more promising buccal insulin products is called the RapidMist™ System. This device can be used to spray a liquid insulin called Oral-lyn™ onto the buccal mucosa. The mist is tasteless and is rapidly absorbed. Insulin administered in this way actually acts more quickly than injected insulin. Additional tests are required, but this system holds great promise as a means to avoid insulin injections.
Some research groups are working on topical forms of insulin such as patches, creams and sprays that can be placed on the skin. This approach has a number of problems. Insulin is a large molecule and it does not penetrate the skin like smaller molecules. It also takes up to a day for insulin to cross from the skin into the blood stream. While topical insulin may be available at some point in the future, a commercial product is still a long way off.
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