Rosiglitazone dosing

Effect of Four Rosiglitazone Doses on Glycemic Parameters (108, 120)... 

THIAZOLIDINEDIONES. The thiazolidinediones, piogli-tazone and rosiglitazone, are given with or without meals. If the dose is missed at the usual meal, the drug is taken at the next meal. If the dose is missed on one day, do not double the dose the following day. If the drug is taken, do not delay the meal. Delay of a meal for as little as y2 hour can cause hypoglycemia. 

When given for about 6 months, pioglitazone and rosiglitazone reduce A1C values by about 1.5% and FPG levels by about 60 to 70 mg/dL at maximal doses. Maximal glycemic-lowering effects may not be seen until 3 to 4 months of therapy. Monotherapy is often ineffective unless the drugs... 

Rosiglitazone (Avandia) is initiated with 2 to 4 mg once daily. The maximum dose is 8 mg/day. A dose of 4 mg twice daily can reduce A1C by 0.2% to 0.3% more than a dose of 8 mg taken once daily. 

Monotherapy-The usual starting dose of rosiglitazone is 4 mg, administered either as a single dose once daily or in divided doses twice daily. In clinical trials, the 4 mg twice-daily regimen resulted in the highest reduction in FPG and HbA-ic-... 

Combination therapy - When rosiglitazone is added to existing therapy, the current dose of sulfonylurea, insulin, or metformin can be continued upon initiation of rosiglitazone therapy. 

Insulin For patients stabilized on insulin, continue the insulin dose upon initiation of rosiglitazone therapy. Dose rosiglitazone at 4 mg daily. Doses greater than 4 mg daily in combination with insulin are not currently indicated. It is recommended that the insulin dose be decreased 10% to 25% if the patient reports hypoglycemia or if fasting plasma glucose concentrations decrease to less than 100 mg/dL. 

Maximum recommended dose The dose of rosiglitazone should not exceed 8 mg/day as a single dose or divided twice daily. 

Hypoglycemia Patients receiving pioglitazone or rosiglitazone in combination with insulin or oral hypoglycemics (eg, sulfonylureas) may be at risk for hypoglycemia reduction in the dose of insulin or sulfonylureas may be necessary. 

Hypoglycemia - If hypoglycemia occurs during up-titration of the dose or while maintained on therapy, a dosage reduction of the sulfonylurea component of rosiglitazone/glimepiride may be considered. 

Special populations - In elderly, debilitated, or malnourished patients, or patients with renal, hepatic, or adrenal insufficiency, the initial dosing, dose increments, and maintenance dosage of rosiglitazone/glimepiride should be conservative to avoid hypoglycemic reactions. 

Patients inadequately controlled on metformin monotherapy - Starting dose is 4 mg rosiglitazone (total daily dose) plus the dose of metformin already being taken (see table). 

For patients on doses of metformin hydrochloride between 1000 and 2000 mg/day, initiation of rosiglitazone/metformin requires individualization of therapy. 

When switching from combination therapy of rosiglitazone plus metformin as separate tablets - Starting dose is the dose of rosiglitazone and metformin already being taken. 

If additional glycemic control is needed-The daily dose may be increased by increments of 4 mg rosiglitazone and/or 500 mg metformin, up to the maximum recommended total daily dose of 8 mg/2000 mg. 

The oral bioavailability of rosiglitazone is 99%. Peak plasma concentrations are observed about one hour after dosing. Rosiglitazone plasma concentration increases in a dose-proportional manner over the therapeutic dose range. 

Rosiglitazone monotherapy has been studied doubleblind in 493 patients for 26 weeks (31). There was a dose-related fall in hemoglobin. Rosiglitazone caused more mild to moderate edema. One patient had a temporary rise in transaminases, which normalized spontaneously. 

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