What medications damage salivary glands? A comprehensive guide to xerostomia and other drug-induced effects

October 7, 2025 •

4 min read

Over 500 medications can cause xerostomia, or dry mouth, which is the most common adverse drug reaction affecting the oral cavity. While dry mouth may seem like a minor annoyance, sustained salivary gland dysfunction can lead to serious oral health complications, such as tooth decay, gum disease, and oral infections. Understanding what medications damage salivary glands is crucial for managing these side effects and maintaining overall oral health.

Quick Summary

This article explores the wide range of medications that can negatively impact salivary gland function, from anticholinergic and cytotoxic drugs to antihypertensives and antidepressants. It details the mechanisms behind reduced salivary flow and gland enlargement, outlines the associated symptoms and long-term risks, and provides information on potential management strategies.

Key Points

Anticholinergic drugs commonly cause xerostomia: Medications with anticholinergic properties, such as antihistamines, antidepressants, and antipsychotics, are a primary cause of dry mouth by inhibiting saliva secretion.
Cytotoxic agents can cause direct damage: Chemotherapy drugs like 5-fluorouracil and cyclophosphamide can directly damage the acinar cells of the salivary glands, leading to glandular atrophy.
Radiotherapy is a major cause of irreversible damage: Radiation treatment for head and neck cancers can cause permanent damage to salivary glands, resulting in severe and long-lasting dry mouth.
Drug-induced damage is often reversible: In many cases, salivary gland function can return to normal after discontinuing the offending medication, particularly with anticholinergic-related xerostomia.
Other drugs cause swelling and inflammation: Certain medications, including ACE inhibitors, radioiodine, and lithium, can cause salivary gland enlargement (sialadenitis or sialadenosis).
Symptom management is crucial for quality of life: Strategies like using saliva substitutes, staying hydrated, and maintaining excellent oral hygiene are vital for managing dry mouth and its associated risks.

The Different Ways Medications Affect Salivary Glands

Medications can damage salivary glands or inhibit their function through various mechanisms, leading to a spectrum of conditions beyond just dry mouth, including swelling and inflammation. The most prevalent issue is xerostomia, often caused by drugs with anticholinergic effects that suppress salivary production. However, other pharmacological classes can cause damage through different pathways, from direct cellular toxicity to altered fluid balance.

Anticholinergic and Other Common Medications Causing Xerostomia

Many widely prescribed drugs have anticholinergic properties that interfere with the nervous system's signaling to the salivary glands, significantly reducing saliva flow. This is one of the most common causes of dry mouth and can affect patients of any age, though it is particularly prevalent in the elderly due to polypharmacy.

Antihistamines: Used for allergies and colds, these block histamine receptors and also have anticholinergic effects.
Antidepressants: Tricyclic antidepressants (e.g., amitriptyline) are notorious for causing dry mouth, but other classes like SSRIs and SNRIs can also be a factor.
Antipsychotics: Medications like clozapine and olanzapine can cause significant hyposalivation.
Antihypertensives: Beta-blockers, ACE inhibitors, and diuretics can decrease salivary flow.
Anti-anxiety and Sedatives: Benzodiazepines such as alprazolam and diazepam are associated with reduced saliva production.
Antiparkinsonian Drugs: These medications act on neurotransmitters and can interfere with salivary function.

Cytotoxic and Chemotherapy Agents

For cancer patients, chemotherapy and radiotherapy can be major culprits behind salivary gland damage. Chemotherapy agents can directly damage the cells of the salivary glands, while radiotherapy targets the glands, leading to long-term and often irreversible damage.

Direct Toxicity: Chemotherapeutic drugs like cyclophosphamide and 5-fluorouracil are known to have direct toxic effects on salivary gland cells.
Oxidative Stress: These agents increase reactive oxygen species (ROS), causing oxidative damage and inflammation within the glandular tissue.
Radiotherapy: Often used for head and neck cancers, radiation can cause severe inflammation and vascular damage to the salivary glands, leading to atrophy and fibrosis. The damage is often dose-dependent and can be permanent.

Mechanisms of Drug-Induced Salivary Gland Damage

The adverse effects of medication on salivary glands are not uniform. They vary depending on the drug's class and mechanism of action. Below are some of the primary ways medications interfere with salivary function:

Neural Inhibition: Anticholinergic drugs block the muscarinic cholinergic receptors in the salivary glands, which are primarily responsible for stimulating saliva production via the parasympathetic nervous system. This is the most common cause of dry mouth.
Fluid Balance Disruption: Diuretics, for example, increase the excretion of body fluids, leading to systemic dehydration that reduces salivary flow.
Vasoconstriction: Some medications can decrease blood flow to the salivary glands through vasoconstriction, thereby limiting the materials available for saliva production.
Direct Cellular Damage: Cytotoxic drugs used in chemotherapy can directly harm the acinar cells within the salivary glands, leading to cell death, glandular atrophy, and reduced function.
Immunological Reactions: Less commonly, some drugs can trigger hypersensitivity or autoimmune-like reactions that cause inflammation and swelling of the salivary glands, a condition known as sialadenitis.
Mineral and Electrolyte Effects: Lithium, a mood stabilizer, has been shown to cause both sialorrhea (excessive salivation) and salivary gland enlargement, likely due to its effects on localized ion balance.

Comparison of Medications and Their Salivary Effects

To better understand the risks, here is a comparison of different medication types and their potential impact on salivary glands:


Medication Class	Primary Salivary Effect	Mechanism of Action	Potential Damage	Reversibility	Examples
Anticholinergics	Hyposalivation (Dry Mouth)	Blocking cholinergic receptors	Functional inhibition, typically not structural damage	Often reversible upon cessation	Antihistamines, TCAs, Antispasmodics
Cytotoxic Agents	Hyposalivation, Atrophy	Direct toxicity to acinar cells, oxidative stress	Cellular damage, glandular atrophy	Potentially reversible, but depends on dosage and duration	5-Fluorouracil, Cyclophosphamide
Diuretics	Hyposalivation (Dry Mouth)	Dehydration from increased fluid excretion	Functional inhibition, indirect effect	Reversible with hydration and cessation	Furosemide, Hydrochlorothiazide
Antihypertensives	Hyposalivation (Dry Mouth)	Mixed effects, including vasoconstriction and anticholinergic effects	Functional inhibition, swelling (ACE inhibitors)	Often reversible, but depends on drug class	Beta-blockers, ACE inhibitors
Lithium	Sialorrhea, Gland Enlargement	Localized irritation, electrolyte changes	Glandular swelling, not necessarily destruction of acini	Reversible upon discontinuation	Lithium Carbonate

Managing and Preventing Drug-Induced Salivary Gland Damage

Managing the salivary side effects of medication requires a collaborative approach with healthcare providers. Patients should not stop taking prescribed medications without consulting their doctor first. However, there are several strategies to mitigate symptoms:

Medication Review: Consult your doctor or pharmacist to review your current drug regimen. Sometimes, a different medication with a lower risk of xerostomia can be prescribed.
Increased Hydration: Drinking plenty of water throughout the day can help compensate for reduced saliva flow.
Use of Saliva Substitutes: Artificial saliva products in the form of sprays, gels, or lozenges can provide temporary relief from dry mouth.
Salivary Gland Stimulants: In some cases, a doctor may prescribe a sialogogue like pilocarpine or cevimeline to increase saliva production, though these have their own set of potential side effects.
Maintain Excellent Oral Hygiene: Scrupulous dental care, including brushing with fluoride toothpaste and using dental floss, is critical to prevent the increased risk of cavities and gum disease associated with dry mouth.
Avoid Irritants: Reduce or avoid alcohol, caffeine, and tobacco, as these can exacerbate dry mouth. Spicy or acidic foods can also be irritating to a dry mouth.

Conclusion

The link between medications and salivary gland damage is a significant concern for many patients, with xerostomia being the most common consequence. From the anticholinergic effects of common allergy and mood-regulating drugs to the severe cytotoxic impact of chemotherapy, the causes are varied. The mechanism can range from functional inhibition of saliva production to direct cellular atrophy and inflammatory reactions. While some damage, particularly that induced by chemotherapy, may be irreversible, many drug-induced salivary issues can be managed or reversed upon discontinuing the offending agent. A proactive approach involving open communication with healthcare providers, diligent oral hygiene, and targeted symptom management is essential for protecting salivary gland health while on necessary medication.

Frequently Asked Questions

Drug classes most likely to cause dry mouth include anticholinergics (antihistamines, antidepressants), certain antihypertensives (diuretics, beta-blockers), antipsychotics, and sedatives. The risk is compounded by polypharmacy, where multiple medications are taken at once.

Yes, it can. Saliva is crucial for protecting teeth from decay by neutralizing acids, remineralizing enamel, and washing away food particles. Reduced salivary flow from medication leaves teeth more vulnerable to bacterial and acidic damage, significantly increasing the risk of cavities.

No. Damage caused by anticholinergic medications and other drugs that primarily inhibit salivary function is often reversible upon cessation of the drug. However, damage from high-dose radiation therapy for cancer is often irreversible.

If you notice persistent, painful, or painless swelling of your glands under your jaw or near your ears, it's possible a medication is the cause. A review of your medical history by a healthcare provider can help identify if a recently started medication is the likely culprit.

Xerostomia is the subjective feeling of dry mouth, usually caused by reduced salivary flow. Sialadenitis is the inflammation or swelling of a salivary gland, which can be caused by infection, obstruction, or certain medications.

Yes. Many over-the-counter drugs, particularly antihistamines found in cold and allergy medications, have anticholinergic effects that can significantly reduce salivary flow and cause dry mouth.

Simple strategies include sipping water frequently, chewing sugar-free gum or lozenges, and using saliva substitutes. In some cases, a doctor might adjust your medication or prescribe a sialogogue to stimulate saliva production.