insulin (cont.)

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STORAGE: Unopened insulin should be stored in a refrigerator between 2 C and 8 C (36 F and 46 F); it should not be placed in a freezer. Insulin vials that are being used can be kept at room temperature for up to a month. All vials should be protected from sunlight and excessive heat. Unused insulin should be thrown away after the expiration date. The vials should never be shaken.

PRESCRIBED FOR: Insulin is prescribed for the treatment of type 1 and type 2 diabetes mellitus.

DOSING: The abdomen is the preferred site for insulin injection, but the sites of injection must be rotated in order to prevent erosion of the fat beneath the skin, a condition called lipodystrophy. Dosing is adjusted for each patient. A combination of short acting/rapid acting and intermediate insulin or long acting insulin are typically used.

DRUG INTERACTIONS: Beta blockers (for example, propranolol [Inderal, Indearl LA, Innopran XL], atenolol [Tenormin]) may mask symptoms of low blood glucose and affect how the body uses glucose. Repaglinide (Prandin) increases the risk of low blood glucose while rosiglitazone (Avandia) increases the occurrence of low blood glucose, fluid retention, and heart failure. Thiazide diuretics, steroids, and estrogens reduce the effect of insulin by increasing blood glucose. Levofloxacin (Levaquin) and other fluoroquinolones increase the risk of high or low blood glucose. Monoamine oxidase inhinbitors (for example selegiline), sulfonylureas (for example, glyburide [Micronase, Diabeta, Glynase, Prestab), and yohimbe increase the risk of low blood glucose. Thyroid hormones increase insulin requirements.

PREGNANCY: Insulin is the drug of choice for controlling diabetes mellitus during pregnancy, that is, it is preferred over oral drugs to reduce blood sugar. NPH, insulin aspart, insulin detemir, and insulin lispro also are used during pregnancy.

NURSING MOTHERS: Insulins are considered safe to use by nursing mothers.

SIDE EFFECTS: Hypoglycemia is the most common side effect that may occur during insulin therapy. Symptoms of hypoglycemia include confusion, nausea, hunger, tiredness, perspiration, headache, heart palpitations, numbness around the mouth, tingling in the fingers, tremors, muscle weakness, blurred vision, cold temperature, excessive yawning, irritability, and loss of consciousness.

Patients may experience blurred vision if they have had elevated blood sugar levels for a prolonged period of time and then have the elevated levels rapidly brought to normal. This is due to a shift of fluid within the lens of the eye. Over time, vision returns to normal. Other side effects that may occur include headaches, skin reactions (redness, swelling, itching or rash at the site of injection), worsening of diabetic retinopathy, changes in the distribution of body fat (lipodystrophy), allergic reactions, sodium retention, and general body swelling. Insulin causes weight gain and may reduce potassium blood levels.

Reference: FDA Prescribing Information


Medically Reviewed by a Doctor on 3/20/2013


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