On rare occasions, treatment with rosiglitazone (Avandia) may cause a profound decrease in high-density lipoprotein (HDL, the “good” cholesterol) and an increase in fasting triglycerides, researchers in the UK warn in the journal Diabetes Care.

“This represents a potentially serious adverse event that requires detailed evaluation,” Dr. Anita Sarker and colleagues from Addenbrooke’s Hospital in Cambridge write.

They describe three patients with type 2 diabetes and High cholesterol in whom treatment with rosiglitazone was temporally related to a sharp decline in blood levels of HDL cholesterol.

The patients had a rapid return of HDL cholesterol to pretreatment levels when the drug was stopped.

Despite this abnormal cholesterol response, all three patients experienced “striking improvement” in blood sugar control with rosiglitazone treatment.

Sarker’s team is aware of two other patients with similar responses to rosiglitazone treatment.

The mechanism of rosiglitazone-induced cholesterol abnormalities remains to be determined, they note.

Sarker told Reuters Health: “It is not clear how common this problem is, although, the fact that this phenomenon was not seen in greater than 1400 patients studied in clinical trials suggests that it is likely to be a rare side effect.”

“However, we would suggest that a full lipid profile that includes HDL cholesterol should be measured before starting [rosiglitazone and similar drugs], and rechecked about three months after.”

SOURCE: Diabetes Care, November 2004.