Dosing and uses of Avandia (rosiglitazone)
Adult dosage forms and strengths
tablet
- 2mg
- 4mg
Type 2 Diabetes Mellitus
Initial 4 mg PO qDay or divided q12hr
If inadequate response afer 8-12 weeks, may increase dose to 8 mg PO qDay or divided q12hr
Monitor: ALT at start of treatment, qMonth for 12 months then q3Months thereafter
Dosage modifications
Active liver disease (ALT >2.5 x ULN): Do not inititate rosiglitazone
Renal impairment: No dosage adjustments required
Coadministration with sulfonylurea: Adjust sulfonylurea dose if hypoglycemia occurs
Pediatric dosage forms and strengths
Safety and efficacy not established
Geriatric dosage forms and strengths
See Adult dosing
Avandia (rosiglitazone) adverse (side) effects
>10%
Increased LDL-cholesteroL
Increased HDL-cholesteroL
Increased total cholesteroL
1-10%
Edema
Hypertension
Heart failure/congestive heart failure
Myocardial ischemia
Diarrhea
Upper respiratory tract infection
Frequency not defined
Accidental injury
Anemia
Back pain
Fatigue
Headache
Hypoglycemia
Myalgia
Sinusitis
Weight gain
Warnings
Black box warnings
Congestive heart failure risk
Thiazolidinediones, including rosiglitazone, cause or exacerbate congestive heart failure in some patients
After initiation, and after dose increases, observe patients carefully for signs and symptoms of heart failure (including excessive, rapid weight gain, dyspnea, and/or edema)
If these signs and symptoms develop, the heart failure should be managed according to current standards of care
Furthermore, discontinuation or dose reduction must be considered
Not recommended in patients with symptomatic heart failure
Initiation with established NYHA Class III or IV heart failure is contraindicated
Contraindications
Hypersensitivity to rosiglitazone
Diabetic ketoacidosis
Heart failure NYHA class III-IV
Active liver disease: do not start rosiglitazone if ALT >2.5 x ULn
Cautions
Fluid retention, which may exacerbate or lead to heart failure, may occur; combination use with insulin and use in congestive heart failure NYHA Class I and II may increase risk of other cardiovascular effects
If ALT >3 x ULN stop treatment; if 1.5-3 x normal, retest qWeek until normal or 3 x normal and need to discontinue
Not for use in diabetes mellitus type 1; mechanism requires presence of endogenous insulin; use with insulin may increase risk of heart failure; not recommended
Thiazolidinediones, which are peroxisome proliferator-activated receptor (PPAR) gamma agonists, can cause dose-related fluid retention, particularly when used in combination with insulin; dose-related edema and weight gain may occur
When used in combination with other hypoglycemic agents, a dose reduction of concomitant agent may be necessary to reduce risk of hypoglycemia
Associated with rare cases of new onset or worsening of macular edema
May result in ovulation in some premenopausal anovulatory women; ensure adequate contraception
Increased risk of fractures of upper arm, hand, or foot in female patients
Dose-related decreases in hemoglobin and hemocrit reported
Pregnancy and lactation
Pregnancy category: C
Lactation: Unsafe
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Avandia (rosiglitazone)
Mechanism of action
Lowers glucose by improving target cell response to insulin without increasing pancreatic cell secretion; activates nuclear peroxisome proliferator-activated receptor gamma, which influences the production of gene products involved in glucose and lipid metabolism
Pharmacokinetics
Bioavailability: 99%
Onset of Action: Initial effect delayed; maximum effect may take up to 12 weeks
Peak Plasma Time: 1 hr
Protein Bound: >99%
Half-Life: 3-4 hr
Vd: 17.6 L
Metabolism: by hepatic CYP2C8 & CYP2C9 (minor extent)
Excretion: urine 64%; feces 22%
