HONOLULU — A drug testing company says it appears amphetamine use is on the rise in Hawaii.

Diagnostic Laboratory Services Inc. said Wednesday that its first-quarter testing found amphetamine use was up 22 percent over the same quarter last year.

The company says its quarterly sample size typically includes between 5,000 and 10,000 drug tests.

It says marijuana usage dropped in the quarter from the end of 2009, but still showed a 9 percent increase from the first quarter of 2009. Usage rates for cocaine and opiates stayed roughly the same.

Diagnostic Laboratory Services' scientific director of toxicology, Carl Linden, called it good news that there wasn't a lot of change from last quarter. But he found it "a little worrisome" that amphetamine use is up from last year.