Oral Health›Health conditions and your mouth

Medicines That Affect Your Mouth

Many everyday medicines can dry your mouth, feed tooth decay, change your gums or taste, stain teeth or affect dental treatment. Here is what to look out for, what helps, and why your dentist needs to know what you take.

Updated September 2026·By the OHA editorial team·8 min read·How we write
Key takeaways
  • Dry mouth is a common side effect of many medicines, and it raises the risk of tooth decay.
  • Some liquid medicines contain sugar. Ask your pharmacist or doctor about sugar-free versions.
  • Certain epilepsy, blood pressure and transplant medicines can make the gums swell or overgrow, and steroid inhalers and antibiotics can lead to oral thrush.
  • Tell your dentist about every medicine you take, including over-the-counter and herbal products, especially blood thinners and bone-strengthening medicines.
  • Never stop a prescribed medicine because of a mouth side effect without talking to your doctor first. Your doctor or dentist may be able to suggest changes or extra protection.

The Better Health Channel (Victoria) says many prescription, over-the-counter and herbal medicines can affect the teeth and gums, depending on the medicine and how long it is taken. The American Dental Association (ADA) says your dentist needs to know what you take, because many medicines also affect dental treatment.

Dry mouth

The ADA calls dry mouth a common side effect of medicines. Saliva protects teeth: the Better Health Channel says it reduces bacteria, neutralises acids, helps repair tooth enamel and washes food away, so a dry mouth significantly increases the risk of tooth decay.

The US National Institute of Dental and Craniofacial Research (NIDCR) says hundreds of medicines can reduce saliva, often those for high blood pressure, depression and bladder control. The Better Health Channel adds antihistamines, decongestants, diuretics (water tablets), Parkinson's medicines, beta blockers and inhalers, and NSW Health lists painkillers and medicines for attention deficit hyperactivity disorder (ADHD).

What to do:

  • Check your medicine's leaflet to see whether dry mouth is a side effect, and see a GP if you think a prescribed medicine is causing it (NHS).
  • NIDCR says your doctor or dentist may be able to change the medicine or dose, or suggest a saliva substitute.
  • Sip water through the day and chew sugar-free gum (NSW Health, Better Health Channel). See dry mouth for more.

Sugar and acid in medicines

NSW Health says cough syrups, cough lollies, antacids and some vitamins can contain sugar and, if used regularly, may raise the risk of tooth decay. It notes that many liquid medicines made for children have sugar added for taste. It advises rinsing your mouth with water after sugary medicines and asking your GP or pharmacist about sugar-free alternatives. The NHS also advises using sugar-free medicines to help prevent tooth decay.

If a medicine is acidic, the Better Health Channel suggests rinsing with water after taking it and waiting at least 30 minutes before brushing.

Gum swelling and overgrowth

The Better Health Channel says some medicines can make the gums swell, become inflamed or overgrow (called gingival hyperplasia). Swollen gums are harder to clean, which raises the risk of gum disease. Medicines linked with gum changes include:

  • Some epilepsy medicines (Better Health Channel). US MedlinePlus lists overgrowth of the gums as a side effect of phenytoin, an anticonvulsant (anti-seizure medicine), and says caring for your mouth properly lowers the risk of gum damage.
  • Some blood pressure medicines. The Better Health Channel says these can cause gum swelling or overgrowth. The ADA lists some calcium channel blockers, a class of blood pressure medicine (MedlinePlus), among medicines linked with gum disease.
  • Ciclosporin (cyclosporine in the US), an immunosuppressant used to prevent rejection of transplanted organs. MedlinePlus lists growth of extra tissue on the gums, and the Better Health Channel says it can raise the risk of gum inflammation and mouth infections.

The ADA also lists steroids, some cancer medicines and oral contraceptives. The Better Health Channel says a dentist can carefully trim overgrown gum tissue.

Oral thrush

Oral thrush is a fungal infection that causes white patches, redness and soreness in the mouth. The NHS says you might get it if you take antibiotics over a long time or use asthma inhalers. The Better Health Channel says high-dose and long-term antibiotics can cause thrush, particularly in people with a dry mouth. The Australian Dental Association says the risk with steroid (corticosteroid) inhalers is higher with regular high doses, and suggests using a spacer.

After using an inhaler: rinse, brush or wait?

The advice differs. The NHS says to rinse your mouth with water or brush your teeth after using a steroid inhaler. The Australian Dental Association says to rinse with water or a fluoride mouthwash, and to wait at least 60 minutes before brushing. It also says asthma medicines can reduce saliva and make the bacteria on teeth more acidic, raising the risk of decay and erosion. Both agree on rinsing.

The NHS says to keep using your inhaler while you treat thrush. See oral thrush.

Taste changes

The Better Health Channel says some medicines can change the way food and drink taste, usually temporarily, and to speak to your dentist or doctor if it persists. The US National Institute on Deafness and Other Communication Disorders lists some common antibiotics and antihistamines among causes of taste disorders. The NHS lists a metallic taste as a common side effect of metronidazole, an antibiotic.

Stained teeth

  • Chlorhexidine, an antiseptic used in some dental and sore throat treatments, commonly stains teeth. The NHS says this is not permanent and goes when you stop using it, and to keep brushing regularly.
  • Liquid iron. The NHS says iron drops (ferrous sulfate) can stain teeth black, and suggests rinsing your mouth with water after taking them. It advises not sucking or chewing iron tablets.
  • Tetracycline, an antibiotic, can give a child's permanent (adult) teeth a yellowish or brownish colour if taken while those teeth are developing (Better Health Channel).

See stained teeth.

Bleeding and blood thinners

The NHS says anticoagulants (medicines that help prevent blood clots, sometimes called blood thinners) can make you bleed too easily, including from the gums. The Better Health Channel says aspirin and other blood-thinning medicines can increase the risk of bleeding during dental treatment, and NSW Health says blood thinners can interfere with clotting and healing, so your dentist needs to know. The NHS says people taking warfarin should carry their anticoagulant alert card and show it to their dentist before any dental procedure. See bleeding gums and blood thinners and dental treatment.

Bone medicines and the jaw

Bisphosphonates and denosumab are used for osteoporosis and some other bone conditions. The Better Health Channel says that in rare cases they can cause serious jawbone problems known as medication-related osteonecrosis of the jaw (MRONJ), in which the jawbone is damaged. The ADA says rare but serious jaw problems can occur in people given bone-strengthening medicines for cancer and, to a lesser extent, osteoporosis.

Always tell your dentist you take them, particularly before a tooth extraction or dental surgery (Better Health Channel). NSW Health notes that your doctor will already have weighed the risks and benefits before prescribing. The NHS says to contact your dentist and your doctor if you get a loose tooth, mouth sores, or swelling or pain in your mouth or jaw while taking alendronic acid, a bisphosphonate. See menopause and oral health and cancer treatment and your mouth.

What to tell your dentist

The Better Health Channel says to tell your dentist about any medicines you take or have recently taken, including prescription, over-the-counter and herbal ones. The ADA says to update them when your health or medicines change. If a medicine is causing problems, the Better Health Channel says your dentist may suggest talking to your doctor about the dose or an alternative, and may recommend fluoride treatment or a higher-strength fluoride toothpaste to protect your teeth.

Do not stop or change a prescribed medicine on your own. The NHS says not to stop one without medical advice, even if you think it is causing symptoms. The Better Health Channel says the same about blood thinners, and MedlinePlus warns that stopping phenytoin suddenly can make seizures worse.

When to see a dentist
  • Your mouth feels dry most of the time, or you notice more decay since starting a medicine.
  • Your gums are swelling, growing over your teeth, or bleeding more than usual.
  • You have white patches or soreness in your mouth, or a taste change that does not go away.
  • You take a bone medicine such as alendronic acid and get a loose tooth, mouth sores, or pain or swelling in your mouth or jaw. The NHS says to contact your doctor as well.
Get help urgently
  • Call 999 (or your local emergency number) if your lips, mouth, throat or tongue suddenly swell, or you are struggling to breathe or swallow after taking a medicine. The NHS says these can be signs of a serious allergic reaction.
  • If you take a blood thinner and bleeding from your gums does not stop quickly, contact your doctor (ADA).

Frequently asked questions

Should I stop a medicine if it is drying my mouth?

No. The NHS says not to stop a prescribed medicine without medical advice. Talk to your doctor, who may be able to change the medicine or dose (NIDCR).

Do I need to stop my blood thinner before dental treatment?

Not on your own. The Better Health Channel says not to change or stop these medicines without medical advice. Tell your dentist what you take. The ADA says your dentist may want to speak with your doctor when planning treatment.

Are children's medicines bad for their teeth?

Some liquid medicines for children contain added sugar (NSW Health). Ask for sugar-free versions, and NSW Health suggests rinsing with water afterwards.

Sources

  1. Teeth and medication, Better Health Channel (Victoria), accessed September 2026
  2. Medications and your mouth: tip sheet (PDF), NSW Health, accessed September 2026
  3. Asthma and oral health, Australian Dental Association, accessed September 2026
  4. Medications and oral health, American Dental Association (MouthHealthy), accessed September 2026
  5. Gum disease, American Dental Association (MouthHealthy), accessed September 2026
  6. Bleeding gums, American Dental Association (MouthHealthy), accessed September 2026
  7. Dry mouth, National Institute of Dental and Craniofacial Research, accessed September 2026
  8. Taste disorders, National Institute on Deafness and Other Communication Disorders, accessed September 2026
  9. Phenytoin, MedlinePlus (US National Library of Medicine), accessed September 2026
  10. Cyclosporine, MedlinePlus (US National Library of Medicine), accessed September 2026
  11. Amlodipine, MedlinePlus (US National Library of Medicine), accessed September 2026
  12. Dry mouth, NHS, accessed September 2026
  13. Tooth decay, NHS, accessed September 2026
  14. Oral thrush (mouth thrush), NHS, accessed September 2026
  15. Side effects of budesonide inhalers, NHS, accessed September 2026
  16. Side effects of metronidazole, NHS, accessed September 2026
  17. Side effects of chlorhexidine, NHS, accessed September 2026
  18. Side effects of ferrous sulfate, NHS, accessed September 2026
  19. How and when to take ferrous sulfate, NHS, accessed September 2026
  20. Anticoagulant medicines, NHS, accessed September 2026
  21. Warfarin, NHS, accessed September 2026
  22. Side effects of alendronic acid, NHS, accessed September 2026

This article is general information about oral health. It is not a diagnosis or a substitute for advice from a dentist or doctor who knows your situation. If you have pain, swelling, bleeding that does not settle, or a problem that is getting worse, see a dental professional. In an emergency, contact your local emergency service.

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