Dry mouth: common causes (including medicines) and what helps

Dental & oral care ·Published 10 October 2026 ·Reviewed 10 October 2026

Written by the Priceline Pharmacy Pacific Fair team. Reviewed by Jason Markey, BPharmSci, MPharm, Owner and Pharmacist.

General health information from a registered pharmacist. It doesn’t replace advice from your own pharmacist or doctor.

Dry mouth (xerostomia) happens when your mouth doesn’t make enough saliva. Many medicines can cause it: the Better Health Channel says about 600 drugs and medications are known to cause dry mouth, and healthdirect lists antidepressants, antihistamines, decongestants, blood pressure medicines, painkillers including opioids, and diuretics among them. Dehydration, breathing through your mouth, some health conditions and cancer treatment can also cause it.

The good news is that there’s plenty you can do: drink water, chew sugar-free gum, try a saliva substitute and take extra care of your teeth. What you shouldn’t do is stop a prescribed medicine on your own. If you think a medicine is behind it, ask one of our pharmacists at Pacific Fair about a medication review.

What are the symptoms of dry mouth?

healthdirect lists symptoms including:

• a dry mouth, and a rough or dry tongue that may stick to the roof of your mouth or your lips
• thick or stringy saliva
• bad breath
• mouth ulcers, bleeding gums or oral thrush
• tooth decay

The Queensland Government also mentions sores and split skin at the corners of the mouth, and healthdirect notes that dry mouth can make speaking, eating, chewing and swallowing difficult.

It’s common, especially as we get older. The Better Health Channel says about 10% of the general population and 25% of older people experience dry mouth, and the Queensland Government notes that saliva flow can also decrease with age.

What causes a dry mouth?

Which medicines can cause a dry mouth?

healthdirect and the Queensland Government both list these types of medicines:

• antidepressants
• antihistamines
• decongestants
• blood pressure medicines
• painkillers, including opioids
• diuretics (fluid tablets)

Chemotherapy and radiotherapy can also cause a dry mouth, especially radiation to the head and neck, according to the Queensland Government.

When you’re working out what might be drying out your mouth, count everything you take, not only your prescriptions. Our medication reviews cover vitamins and over-the-counter products too.

What else causes a dry mouth?

• Dehydration. The Better Health Channel notes that not drinking enough fluid can cause thick saliva and a dry mouth. Long beach days and humid Gold Coast summers make it easy to fall behind on water.
• Breathing through your mouth. The Better Health Channel lists a tendency to mostly breathe through the mouth, often because of a stuffy nose or blocked sinuses. healthdirect also lists snoring.
• Health conditions. These include Sjögren’s syndrome, diabetes, stroke, Alzheimer’s disease, lupus and rheumatoid arthritis (healthdirect), and Parkinson’s disease (Better Health Channel).
• Cancer treatment. The Better Health Channel says chemotherapy or head and neck radiotherapy may temporarily reduce the ability of the salivary glands to make saliva.
• Lifestyle. The Australian Dental Association (ADA) lists smoking and drinking a lot of alcohol, tea or coffee, and healthdirect lists anxiety or stress.

Why does a dry mouth matter?

Saliva helps protect your mouth, and the Queensland Government notes it helps prevent fungal infections. It also warns that a dry mouth can rapidly deteriorate your oral health.

• The ADA puts it simply: “A dry mouth is a dangerous mouth”, because tooth decay can develop faster.
• healthdirect says dry mouth “greatly increases your chance of developing tooth decay or gum disease”.
• The Better Health Channel notes that decay can form along the gum line and on the lower front teeth, and that dry mouth makes oral thrush and mouth ulcers more likely. If you’re getting ulcers, our guide to mouth ulcer treatment can help.
• If you wear dentures, take them out every night and keep them clean (healthdirect and the ADA).

What helps a dry mouth?

Everyday habits

• Drink plenty of water, and sip water as you eat (ADA).
• Choose water over sugary drinks, fruit juice and cordial (healthdirect), and cut back on tea and coffee (ADA).
• Chew sugar-free gum to get saliva flowing. Some contain xylitol, a sweetener the ADA says can help prevent tooth decay.
• Avoid smoking and alcohol.
• Go easy on foods that irritate a dry mouth, such as citrus, spicy food and sharp-edged snacks (healthdirect), and on sticky, sugary food and sour lollies (ADA and Better Health Channel).
• Have soups, and add sauces to dry foods (ADA).
• Use a humidifier in the bedroom at night, and keep your lips moisturised with a greasy lip balm (healthdirect, ADA and Better Health Channel).
• Breathe through your nose when you can (healthdirect).

Products from the pharmacy

• Saliva substitutes. The Queensland Government says these are available from most pharmacies. The ADA describes products that act as a replacement for saliva, including gels, mouthwashes, mouth sprays and toothpastes.
• Dry mouth lozenges that contain xylitol (ADA).
• An alcohol-free mouthwash. The Queensland Government advises avoiding mouth rinses that contain alcohol or peroxide.
• Higher-fluoride toothpaste. healthdirect suggests toothpaste and mouthwash with higher fluoride levels, and the ADA notes that high fluoride toothpaste is sold at pharmacies and some dental clinics, not supermarkets. The Queensland Government says a dental practitioner may recommend it, so ask your dentist whether it’s right for you.

You can browse mouth treatments on priceline.com.au, which include dry mouth gels and sprays, or ask our pharmacists in store.

Help from your dentist and doctor

Your dentist may suggest brushing gently after meals, flossing every day and having check-ups more often (ADA). healthdirect says your doctor may prescribe a medicine to help stimulate saliva, and the ADA notes that some medicines can help your saliva glands produce more saliva.

Should you stop a medicine that’s drying out your mouth?

No. healthdirect’s advice is clear: “do not make any changes to your doses without first talking with your doctor”. The ADA agrees: “Never make medicine changes all by yourself.” The Better Health Channel says to keep taking your medication, even if it may be the cause.

What you can do is raise it. Your doctor may be able to change the dose or swap the medicine (Better Health Channel and healthdirect), and the ADA suggests asking your doctor whether you could take a smaller amount.

How can our pharmacists help?

A medication review is a good place to start. It’s a free one-on-one conversation with a pharmacist for Medicare card holders, covering everything you take, including vitamins and over-the-counter products. It takes about 20 to 30 minutes and you don’t need to book. We can help you work out which medicines might be contributing and what to ask your GP.

We can also help you choose between saliva substitutes, xylitol lozenges, alcohol-free mouthwash and high-fluoride toothpaste, and check they suit your other medicines. If you need a doctor, the Help Medical GPs are right inside our store at Pacific Fair.

When to see a pharmacist or GP

Talk to a pharmacist if your mouth has felt dry since you started a new medicine, or you’d like help choosing dry mouth products. See a GP (our in-store Help Medical GPs are one option) if:

• your dry mouth bothers you or affects your quality of life
• it’s severe and you don’t know the cause (the ADA suggests a check-up with your doctor or dentist)
• you’re finding it hard to speak, chew or swallow
• you think a prescribed medicine is the cause (keep taking it until you’ve spoken with your doctor)
• you notice oral thrush, mouth ulcers or sores at the corners of your mouth

If you have a dry mouth, healthdirect also recommends seeing your dentist regularly so problems are picked up early. For health advice at any hour, Queensland’s 13 HEALTH line (13 43 25 84) is available 24/7 for the cost of a local call.

This article is general information only and isn’t a substitute for personal advice from your doctor or pharmacist. Always read the label and follow the directions for use. If symptoms persist or you’re worried, talk to your pharmacist or GP. In an emergency, call 000.