Now, thousands of prescriptions get filled every day with no problem. But state pharmacy investigators tell KOMO 4 News that hundreds of mistakes go unreported, because you don't know whom to call.

State investigators say for every one medicine mix-up they hear about, at least 10 more go unreported.

"It scares me. It scares me to know that I can't trust my pharmacist," said Julie Dunlap.

This past summer, Julie Dunlap's baby had a sinus infection. The doctor prescribed the antibiotic Amoxicillin, which for 3-month-old Jennah, should have been diluted to an infant dosage.

Instead, she got twice the concentration the doctor ordered.

Julie noticed the liquid was too thick and went back to the pharmacy. Luckily, baby Jennah only got one double dose and had no adverse reaction.

But, Julie had no idea where else to take her complaint.

"The first thing I thought of was to call the Food and Drug Administration," she said.

Most consumers don't know that pharmacies are regulated by the Board of Pharmacy in Olympia, whose biggest focus is medication errors.

"As far as we're concerned, that's the top of our priorities," said Don Williams of the Board of Pharmacy.

Despite a recent decrease in complaints, the Pharmacy Board says too many physicians still write illegible prescriptions, and too many pharmacies drop the ball.

"No prescription should leave a pharmacy before it gets double checked by the pharmacist," Williams said.

But it doesn't always happen. Gina Hoppa is supposed to take purple pills for depression. The pharmacy gave her blue pills instead. It was the same anti-depressant, but the wrong dosage.

"You start messing around with the dosages, it could cause serious mental problems," she said.

To make things worse, it happened again with another prescription.

"A couple of months later I went back and got a refill of my birth control pills," she said.

Instead of the "Progestin only" pill her doctor prescribed, the pharmacist gave her pills with estrogen.

The problem: Gina was still breastfeeding her son. Estrogen is a no-no for nursing mothers.

"This is my child. This could have harmed my child," she said.

Both Gina and Julie got their prescriptions from two different Walgreen's -- one of the biggest pharmacy chains in the state.

Walgreen's Corporate spokeswoman, Carol Hively, told KOMO 4 News the company accepts blame, and will continue to closely monitor the two stores involved. An employee at one of the stores is no longer with the company.

Josephine Legan, 78, got a refill of pain medication Celebrex for arthritis from a Rite-Aid store. She takes it three times a day.

Only her refill in June was not Celebrex. It was "Celexa" -- an anti-depressant.

Josephine unknowingly took anti-depressants for nearly five weeks.

"I just slept and slept and slept and slept," she said.

Then her daughter Terri questioned the pharmacists and uncovered the mix-up.

"And I was screaming at the pharmacist, like 'How the hell could this happen?' " Terri said.

Their response: Two medicines with similar names, side by side on the pharmacy shelf. Someone had grabbed the wrong bottle.

Jody Cook, a Rite-Aid corporate representative, told us the pharmacist involved has been reprimanded and retrained, and the company has taken steps to prevent such an error from happening again.

Investigators say there is no pattern of problems at any pharmacy. The mistakes are random and unrelated.

The State Board of Pharmacy says the most common prescription errors are the wrong dose, the wrong drug and mislabeled medicine.

And, guess what? Pharmacies don't always report mix-ups. They don't have to.

Which brings it back to you -- know your rights.

"For one thing, the pharmacist is supposed to discuss the medication with the patient," Williams said.

Before you pay for your medicine, double-check the contents. If it's a refill, does it look the same as before?

If it's a medicine you're taking for the first time, ask questions. What is the medication? What's it for?

Most pharmacists volunteer the information, but if yours doesn't, ask.

And urge your doctor to write the purpose of the medication on the original prescription so it's included on the label.

And before you go the pharmacy, go to your computer and do an Internet search for "prescription drug reference".

You'll get full details about the drug you're taking and a picture showing exactly what it should look like.

More Information:

Pharmacists Top Public Trust Polls

The Washington State Pharmacy Association says it shares concern about prescription mistakes. In addition to taking part in the state's Medication Safety Task Force, it provides continuing education to its members on the subject of error prevention.

"Pharmacists care deeply about their patients and their well being, and take the utmost of care to fill prescriptions accurately.", says Association President Charles J. Kahler.

The association says most pharmacies have an ongoing quality improvement program to detect errors and determine ways to prevent them from reoccurring.

"Pharmacists are at the top of public trust polls for a reason," says the group's President-elect Michael Brandt. "We provide patients with clear, concise information based on fact, with the best interest of the patient at the forefront. "

The WSPA says pharmacists must work in a "pressure cooker" atmosphere, filling an average of 17 prescriptions an hour. That works out to one prescription every 4 minutes. The group says patients can help reduce the error producing stress placed on pharmacists, by allowing the pharmacists sufficient time to fill their prescriptions.

Sources of Prescription Errors

Between 1998 and 2002, the source of errors investigated by the state involved the following: