ROSIGLITAZONE MALEATE (ros-i-glit'a-zone) Avandia Classifications: hormone; antidiabetic; thiazolidinediones; Therapeutic: antidiabetic Pregnancy Category: C
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Availability
2 mg, 4 mg, 8 mg tablets
Action
Antidiabetic agent that lowers blood sugar levels by improving target cell response to insulin in Type 2 diabetics. It reduces
cellular insulin resistance and decreases hepatic glucose output (gluconeogenesis).
Therapeutic Effect
Reduces hyperglycemia and hyperlipidemia, thus improving hyperinsulinemia without stimulating pancreatic insulin secretion.
Indicated by decreased HbA1C.
Uses
Adjunct to diet in the treatment of type 2 diabetes. May also be used in combination with metformin.
Contraindications
Hypersensitivity to rosiglitazone; cardiovascular disease, particularly hypertensive patients with New York Heart Association
Class III and IV cardiac status (e.g., CHF); pregnancy (category C), lactation; active hepatic disease or ALT >2.5 times
normal.
Cautious Use
As monotherapy in Type 1 diabetes mellitus or diabetic ketoacidosis; CHF or risk for CHF; hepatic impairment. Safety and
efficacy in children <18 y are not established.
Route & Dosage
Type 2 Diabetes Mellitus Adult: PO Start at 4 mg q.d. or 2 mg b.i.d., may increase after 12 wk (max: 8 mg/d in 12 divided doses)
Hepatic Impairment Do not use if ALT >2.5 x ULN.
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Administration
Oral
- Do not initiate therapy if baseline serum ALT >2.5.
- Store at 15°30° C (59°86° F) in tight, light-resistant container.
Adverse Effects (≥1%)
Body as a Whole: Edema,
anemia, headache, back pain,
fatigue.
CV: edema, fluid retention, exacerbation of heart failure,
increased risk of heart attack. GI: Diarrhea.
Respiratory: Upper respiratory tract
infection,
sinusitis.
Special Senses: Macular edema.
Other: Hyperglycemia.
Interactions
Drug: Insulin may increase risk of heart failure or edema; enhance
hypoglycemia with
oral antidiabetic agents,
ketoconazole, gemfibrozil may increase effect.
Bosentan may reduce effect.
Herbal: Garlic, ginseng, green tea may potentiate hypoglycemic effects.
Pharmacokinetics
Absorption: 99% from GI tract.
Peak: 1 h, food delays time to peak by 1.75 h.
Duration: >24 h.
Distribution: >99% protein bound.
Metabolism: In liver (CYP2C8) to inactive metabolites.
Elimination: 64% urine, 23% feces.
Half-Life: 34 h. Liver disease increases
serum concentrations and increases
half-life by 2 h.
Nursing Implications
Assessment & Drug Effects
- Monitor for S&S of hypoglycemia (possible when insulin/sulfonylureas are coadministered).
- Monitor for S&S of CHF or exacerbation of symptoms with preexisting CHF.
- Lab tests: Liver function and serum ALT at baseline, then q2mo for first year; then periodically (more often when elevated);
periodic HbA1C, Hgb and Hct, and lipid profile.
- Withhold drug and notify physician if ALT >3 times normal or patient jaundiced.
- Monitor weight and notify physician of development of edema.
Patient & Family Education
- Have blood tested for liver function every 2 mo for first year; then periodically.
- Be aware that resumed ovulation is possible in nonovulating premenopausal women.
- Use or add barrier contraceptive if using hormonal contraception.
- Report immediately to physician: S&S of liver dysfunction such as unexplained anorexia, nausea, vomiting, abdominal pain,
fatigue, dark urine; or S&S of fluid retention such as weight gain, edema, or activity intolerance.
- Combination therapy: May need adjustment of other antidiabetic drugs to avoid hypoglycemia.