Getting a drug prescription to treat a simple infection isn’t always so simple. Drug prices are on the rise; doctor visits can be time-consuming, expensive; and 40 million Americans have no insurance to help pay.

For many, it’s easier to get drugs for a pet cat or fish — and take those pills themselves. Animals are prescribed many of the same medications humans are, sometimes for the same conditions, and there are plenty of Internet sites providing advice on drug dosage.

“The use of animal antibiotics without prescription is a major issue for us,” said Dr. Don Klingborg, associate dean of public programs at the University of California, Davis School of Veterinary Medicine. “This kind of use can cause adverse events for the people taking them, and also lead to more antibiotic resistance in the diseases we’re trying to control.”

With increasing amounts of prescription drugs moving across the Mexican border and through Internet pharmacies, a variety of vet medicines are likely being bought and sold for human use, doctors say. Some emergency-room doctors say patients occasionally turn up with veterinary pain medications, sleeping pills and anabolic steroids, among other products.

“I’ve seen people that go to Mexico for the meds and return with the vet form instead of the human form,” said Dr. James Keany, an emergency-room physician in Mission Viejo, Calif.

Allergic reaction

One of the biggest dangers, he said, is having a severe allergic reaction to an unknown drug. “I’ve seen people come to the ER with allergic reactions, usually saying, ‘This looks just like when I took penicillin.”‘ They were taking penicillin without knowing it, he said.

Perhaps the biggest loophole in the regulation of veterinary drugs is the sale of fish antibiotics in pet stores, according to Brandon Goff, of the Pentagon Clinic in Washington, D.C.

In a letter to the New England Journal of Medicine, Goff and two other Pentagon doctors reported the case of an Army Special Forces soldier who had been treating a sinus infection for three months without a prescription. After some questioning, Goff said, the middle-age serviceman acknowledged that he’d been buying the drugs from the fish aisle of a local pet shop.

Easily available

Goff visited some pet stores and Internet sites that sell pet supplies and found a wide range of antibiotics available: packages of penicillin, in 250-milligram tablets; tetracycline, in 250-milligram capsules or tablets; erythromycin, in 200-milligram tablets. In all, there were about a dozen antibiotics commonly used by humans sold in clearly labeled doses.

Many of the same products are available through Internet sites operated by large pet-product chain stores or discount veterinary supply outfits.

“This soldier could have come in and seen me any time, but he’s a guy trained to think independently and take care of himself,” Goff said.

When bombarded — but not killed off — by antibiotic drugs, bacteria eventually evolve defenses against the drugs. The tougher bugs are difficult to eradicate.

In recent years, for example, scientists have detected strains of the tuberculosis bacterium resistant to nearly every antibiotic available.

Shawn Underwood, a spokesman for Petco, a large pet-supply chain based in San Diego, said the company had not heard of customers buying fish drugs for personal use.

“It’s news to us,” he said. “I’m sure store managers wouldn’t sell the products if they thought they weren’t being used properly.”

Recreational use

Other pet-shop owners, though, have noticed a problem. “I quit selling drugs 10 years ago for that very reason: People would come in and buy a bunch of medicine and you knew they didn’t have a dog,” said Hervey Chapman, owner of Verdugo Pet Shop in Los Angeles. “They were buying the drug for themselves.”

Some animal medications have a following among recreational drugs users. Dr. Elizabeth Curry-Galvin, of the American Veterinary Medical Association in Schaumburg, Ill., said there have been burglaries of veterinarians’ offices in which the anesthetic ketamine — used most commonly on animals — was stolen.

Sometimes known as “vitamin K,” when used in clubs or at parties, the drug can cause hallucinations and disorientation — a high that lasts up to two hours, doctors say.

“It’s a very important anesthetic for animal medicine, but we have to advise vets to keep as little of it as possible and put it under lock and key,” Curry-Galvin said.