MINNEAPOLIS -- It looks like an oversized cash machine. But instead of spitting out greenbacks, it dispenses prescription medicine.

For Michael Powell, who recently slipped his debit card into one of the machines at North Memorial Medical Center in Robbinsdale, Minn., the convenience can't be topped.

"It took two minutes, maybe," he said. "If I go to my drugstore, I'll wait at least a half hour."

InstyMeds, an Eden Prairie, Minn., company is bringing vending machine convenience to the world of medicine. The number of the machines has doubled in the past three years, with 200 installed in 33 states and the District of Columbia, mostly in emergency rooms and urgent-care centers.

Advantages include a reduced risk of giving a patient the wrong drug, according to the company. But pharmacists also point to limitations, such as the machine's inability to counsel patients.

"It's not quite as seamless as going to a cash machine and saying, 'Give me $200,' " said Bruce Thompson, pharmacy services director for Hennepin County Medical Center in Minneapolis.

The machines dispense up to 100 of the most commonly prescribed drugs, including pain relievers, antibiotics, asthma inhalers, treatments for bee stings, and medications for colds and flu.

Patients tap out a number from their doctors, answer a few questions, and make a payment. A robot triple-checks the request against a bar code, sticks on an instruction label, and drops the medicine out a chute.

"It's like using an ATM," said Mr. Powell, 57, of New Brighton, Minn., a repeat user of the InstyMeds dispenser. "It guides you through it, takes cash and debit cards, and has a brain. It knows I'm on Medicare and what I have to pay for my co-pay."

A phone attached to the machine is staffed 24 hours a day by insurance specialists in Eden Prairie who can answer questions, help patients work through co-payment issues, or even direct them to the nearest pharmacy.

Dr. Jeff Vespa, assistant medical director of the emergency department at North Memorial, said about 18 percent of all prescriptions at the hospital were dispensed by the machine last month. It is one of 48 across Minnesota.

Some pharmacists have not been so quick to embrace the InstyMeds concept. They worry that patients need face-to-face counseling, especially those taking multiple drugs that might interact.

Mr. Thompson of Hennepin County Medical Center said the machines are great for rural areas where patients might need to drive long distances to get to a pharmacy. But he said it can be cumbersome for some doctors to fill out the form InstyMeds uses for prescriptions.

And if a patient happens to be trying to buy the medication at a time when the insurance company is doing a backup or is offline, he or she could be stuck with paying the entire cost up front.

Aside from companies that supply urgent-care centers with small supplies of prelabeled bottles of common prescriptions, InstyMeds has few competitors, said Dr. David Stern of Practice Velocity, a medical software company and network of 19 urgent-care clinics in Chicago.

"It's a very good product, but it's not a cheap product," said Dr. Stern, who doesn't use InstyMeds in his clinics. "In the emergency room, it's a no-brainer. There are other options for urgent-care centers that are less costly."

Brad Schraut, InstyMeds chief executive officer, said he understands the concerns. There's a reason grocery chains and big-box retailers such as Target and Wal-Mart want a piece of the $500 billion prescription business, he said. Industry figures show that the average patient spends $73 at the store beyond the price of the medications at the time of pickup.

Mr. Schraut said InstyMeds intends to remain focused on the 15 percent of the prescription business that involves acute-care medicine -- drugs for severe pain or that need to kick in right away to prevent infection.

The machines are in compliance with privacy laws and were cleared by the federal Drug Enforcement Agency as well as state regulators in every state in which InstyMeds does business.

The firm owns the machines, which cost about $55,000 each, and makes money on installation charges and a fee on each transaction.

First Published August 31, 2011, 4:15 a.m.