Pharmacists in Western Australia can now prescribe antibiotics for urinary tract infections in women in a bid to ease pressure on general practitioners.

Previously, women had to see a doctor to get an official diagnosis but pharmacists who have undergone a national training program have the green light to begin treating the infection.

Only women aged 18 to 65 are able to have a consultation with a pharmacist and more complex cases are required to be transferred to a medical practitioner.

The consultations must be paid for privately and are not covered by Medicare or bulk billed.

The Australian Medical Association WA and the Royal Australian College of General Practitioners hit out at the announcement and called for it to be rigorously evaluated.

They are concerned about potential harms including the risk of over-prescribing antibiotics which could fuel resistance and make treating infections harder.

Not all risks can be mitigated, according to RACGP WA Chair Dr Ramya Raman.

"There is no such thing as a simple diagnosis. GPs train for over 10 years before they diagnose patients and do ongoing training for their entire working life," Dr Raman said.

"Pharmacists aren't trained to diagnose or prescribe."

Health Minister Amber-Jade Sanderson said the program meant women had alternative to seeking a help at a GP clinic.

"This new service will help Western Australian women access timely, appropriate and convenient treatment for UTI symptoms at their local pharmacy," she said.

Similar programs have been rolled out or are under consideration in Queensland, NSW, Victoria and South Australia.