Sodium fluoride can be administered orally or topically to provide a source of fluoride, an important mineral. Fluoride is the ionic form of fluorine. The negatively charged fluoride combines with positively charged calcium or sodium ions to form stable compounds. Topical fluorides, such as toothpastes, mouthrinses, gels, and foams, strengthen teeth already present in the mouth making them more decay-resistant. Systemic fluorides, such as tablets, fluoridated water, lozenges, and drops, are ingested, incorporated into forming teeth, and distributed into saliva, which continually bathes the teeth. Although water contains fluoride ions, natural water in some areas has a very low concentration of fluoride. Fluoride reduces cavity development in both children and adults. Fluoride also helps repair the early stages of tooth decay even before the decay becomes visible. Sodium fluoride can increase bone density and thus, has been investigated in the management of postmenopausal osteoporosis. Other possible uses include metabolic and neoplastic bone diseases, multiple myeloma, otosclerosis, and metastatic prostate carcinoma. Sodium fluoride was approved by the FDA in 1945.
General Administration Information
For storage information, see specific product information within the How Supplied section.
Route-Specific Administration
Oral Administration
-To reduce any unpleasant GI effects, fluoride can be taken with food that does not contain calcium.
Oral Solid Formulations:
-Chewable tablets should be dissolved in the mouth or chewed before swallowing.
-Administration at bedtime after brushing teeth is recommended.
Oral Liquid Formulations:
-Oral solution can be dropped directly into the mouth or mixed with cereal or fruit juice.
Topical Administration
-Sodium fluoride is applied to the teeth in the form of gels, mouthwashes, or toothpaste.
-Children require supervision in the use of topical preparations.
-Mouthwashes should not be swallowed.
-The mouth should be rinsed after toothpaste use.
-Avoid overuse or ingestion of any topical product.
-After use of a fluoride rinsing solution, patients should not eat, drink or rinse with water for at least 30 minutes.
Both oral and topical use of sodium fluoride have produced allergic and sensitivity reactions. Urticaria, exfoliative dermatitis, atopic dermatitis, stomatitis, and respiratory problems have occurred.
Too much fluoride can cause dental fluorosis, producing mottling, staining, or hypoplasia of tooth enamel. Chronic systemic intake can produce general fluorosis, with asthenia, weight loss, and anemia. Skeletal bones may also be affected, and in extreme cases become brittle. When sodium fluoride is used to treat osteoporosis there is an increase in bone mass of the spine. The incorporation of fluoride into hydroxyapatite changes the size and structure of the crystals. Although bone mass increases, the altered structure can decrease mechanical efficiency and result in increased fracture rates. Even if spinal fracture is reduced, the incidence of hip and other nonvertebral fracture can be increased. Microfractures may produce ankle, knee, or foot pain.
Large, systemic therapeutic doses of sodium fluoride have produced GI bleeding, abdominal pain, nausea, vomiting, hypersalivation, and hematemesis, usually within 30 minutes of ingestion. Large doses may also produce rheumatic effects, such as synovitis.
Excessive systemic exposure to fluoride can cause abnormal bone formation, therefore sodium fluoride should be administered with caution in patients with arthralgia or rheumatoid arthritis. Adverse rheumatic effects have been recorded with sodium fluoride use, and arthralgia may be exacerbated. Too much fluoride can also cause dental fluorosis, producing mottling, staining, or hypoplasia of tooth enamel. Patients who have dental fluorosis should not use extra fluoride as a dietary supplement. If the drinking water concentration of fluoride ions exceeds 0.7 ppm, do not take additional sodium fluoride.
Porcelain and ceramic denture restorations can be affected by acidulated phosphate fluoride, which is a mixture of sodium fluoride and phosphoric acid. Patients with such dental work should use only neutral sodium fluoride.
Sodium fluoride can be beneficial to children who live in areas that have an inadequate supply of fluoride in the drinking water, but they should not take 1 mg tablets if the water contains >= 0.3 ppm. Fluoridated water may be consumed from sources other than the home water supply, such as the workplace, school and/or day care, bottled water, filtered water and from processed beverages and foods prepared with fluoridated water. Information on an area's water fluoride concentration may be found at the US Centers for Disease Control website. Fluoride overdose in children can result in dental fluorosis and osseous changes. Cautious use of sodium fluoride solution in children is also advised. In general, oral fluoride rinsing solution should not be used in neonates, infants and children under 6 years old, and children age 6-12 years require careful supervision to ensure proper use. Oral rinsing solutions should not be swallowed when the drinking water concentration of fluoride exceeds 0.7 ppm. The use of fluoride gels in these age groups also requires proper supervision. Topical sodium fluoride preparations should not be used in infants. Infants at least 6 months of age may need systemic fluoride supplementation (see Dosage).
Topical stannous and sodium fluoride preparations (e.g., gels, toothpastes, foams, and mouthwashes) as well as oral preparations are considered safe to use during pregnancy as directed and when needed. Epidemiological studies conducted in areas with high levels of naturally fluoridated water showed no increase in birth defects. Heavy exposure to fluoride during in utero development may result in skeletal fluorosis which becomes evident in childhood.
Infants of mothers that are breast-feeding and use topical sodium fluoride should not receive much, if any, fluoride from the breast milk, as topical use by the mother should not result in increased maternal systemic fluoride concentrations. Use of oral sodium fluoride within the recommended daily dietary intake for lactating women is generally recognized as safe. An upper intake concentration for fluoride of 10 mg/day has been established for lactation, because an extremely small proportion of fluoride in drinking water is transferred to the breast milk. Reduced milk production was reported in farm-raised fox when fed a diet containing a high concentration of fluoride (98 to 137 mg/kg of body weight); no adverse effects on parturition, lactation, or offspring were seen in rats administered fluoride up to 5 mg/kg of body weigh, a dose at least 200 times greater than the recommended daily dose in humans. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, healthcare providers are encouraged to report the adverse effect to the FDA.
Sodium fluoride for ingestion can exacerbate GI disease or ulceration and should not be used in patients with gastric problems. Topical application may not bother patients, as long as the formulation is not swallowed purposely or inadvertently.
Severe renal impairment can lead to reduced renal clearance of fluoride and increased blood concentrations. Sodium fluoride should be used with caution in patients with renal dysfunction. Patients with uremia and high concentrations of fluoride in serum have experienced aggravation of existing bone disease, possibly through increased bone demineralization. Dialyzed patients with uremia have been found to have increased serum fluoride concentrations. Fluoride in the dialysate bath has been implicated. Deionization of water is recommended if a fluoridated water supply is used for dialysis of patients with uremia.
There are some sodium fluoride products that contain tartrazine. Use with caution in patients who have tartrazine dye hypersensitivity.
For nutritional supplementation in healthy individuals; a recommended daily allowance (RDA) has not been established; the adequate intake (AI) is used in place of RDA, as listed:
Oral dosage (expressed as fluoride ion):
Adults: 3.1 mg PO per day for females; 3.8 mg PO per day for males. Medicinal supplementation is normally not needed in healthy adults.
Adolescents: 2.9 mg PO per day for females; 3.2 mg PO per day for males. Medicinal supplementation of fluoride is normally not needed in healthy adolescents; fluoride supplementation may be needed for adolescents < 16 years of age for prevention of dental caries.
Children 9 to 13 years: 2 mg PO per day. Children may need fluoride supplementation for prevention of dental caries depending on the concentration of fluoride in municipal tap water.
Children 4 to 8 years: 1.1 mg PO per day. Children may need fluoride supplementation for prevention of dental caries depending on the concentration of fluoride in municipal tap water.
Children 1 to 3 years: 0.7 mg PO per day. Children may need fluoride supplementation for prevention of dental caries depending on the concentration of fluoride in municipal tap water.
Infants 6 to 12 months: 0.5 mg PO per day. Children may need fluoride supplementation for prevention of dental caries depending on the concentration of fluoride in municipal tap water.
Infants younger than 6 months: 0.01 mg PO per day through human breast milk content; formula-fed infants usually ingest higher amounts if formula is prepared with fluoridated water. Because the fluoride intake of infants at this age does not appear to influence the development of dental caries, medicinal supplementation of fluoride is not necessary, even for breast-fed infants.
For dental caries prophylaxis:
NOTE: Fluoridated water may be consumed from sources other than the home water supply, such as the workplace, school and/or day care, bottled water, filtered water and from processed beverages and foods prepared with fluoridated water.
-topical mouth rinses for use when the fluoride concentration in drinking water is unknown:
Topical dosage (0.05% sodium fluoride solution):
Children 6 to 12 years: 10 mL rinsed around the teeth for 1 minute, then expectorated. Use once daily after brushing and flossing.
Children 1 to 5 years: Do not use; young children have a tendency to swallow the rinses.
Topical dosage (0.2% sodium fluoride solution):
Adults: 10 mL rinsed around the teeth for 1 minute, then expectorated, use once per week after brushing and flossing.
Adolescents: 10 mL rinsed around the teeth for 1 minute, then expectorated, use once per week after brushing and flossing.
Children 6 to 12 years: 5 mL rinsed around the teeth for 1 minute, then expectorated, used once per week (after brushing and flossing).
Children 1 to 5 years: Do not use; young children have a tendency to swallow the rinses.
-oral supplementation for dental caries prophylaxis in areas where fluoride concentration in drinking water greater than 0.6 ppm:
Oral dosage:
Children and Adolescents 1 to 16 years: Supplementation not necessary. Use of fluoride supplements is contraindicated in areas where fluoride water content is at least 0.7 ppm. If fluoride concentration in drinking water exceeds 0.6 ppm, do not take additional oral sodium fluoride for dental caries prophylaxis. An 8 fluid ounce glass of fluoridated drinking water (1 ppm or 1 mg/L) provides about 0.2 mg of fluoride.
-oral supplementation for dental caries prophylaxis in areas where the fluoride concentration in drinking water is 0.3 to 0.6 ppm:
Oral dosage (expressed as fluoride ion):
Children and Adolescents 6 to 16 years: 0.5 mg PO per day.
Children 3 to 5 years: 0.25 mg PO per day.
Infants and Children 1 to 2 years: Supplementation not necessary.
-oral supplementation for dental caries prophylaxis in areas where the fluoride concentration in drinking water is less than 0.3 ppm:
Oral dosage (expressed as fluoride ion):
Children and Adolescents 6 to 16 years: 1 mg PO per day.
Children 3 to 5 years: 0.5 mg PO per day.
Children 1 to 2 years: 0.25 mg PO per day.
Infants 6 to 12 months: 0.25 mg PO per day.
Infants 1 to 5 months: Supplementation not necessary.
For dentin desensitization on exposed root surfaces:
Topical dosage (0.2% sodium fluoride solution):
Adults: After brushing and flossing the teeth, rinse 10 mL over the affected area for 1 minute, then expectorate; use once daily.
For the relief of bone pain*:
-for palliative management of bone pain* in patients with metastatic prostate cancer*:
Oral dosage (expressed as sodium fluoride):
Adults: 100 mg PO per day for the palliative management of bone pain.
-for palliative management of bone lesions in multiple myeloma* either alone or as an adjunct to calcium carbonate therapy:
Oral dosage (expressed as sodium fluoride):
Adults: 100 to 200 mg PO per day for the palliative management of bone lesions.
For stabilizing loss of hearing in patients with otosclerosis*:
Oral dosage (expressed as sodium fluoride):
Adults: 25 to 60 mg PO per day.
For the treatment of postmenopausal osteoporosis*:
-for postmenopausal osteoporosis as an adjunct to calcium and vitamin D, or, as an adjunct to calcium and estrogen:
Oral dosage (expressed as sodium fluoride):
Adults: 30 to 100 mg PO per day.
-for postmenopausal osteoporosis as an adjunct to calcium citrate:
Oral dosage (expressed as sodium fluoride):
Adults: 25 mg PO of a sustained-release dosage form PO twice per day, for 12 months, followed by a 2-month drug-free period. This 14-month regimen was repeated over a 4-year period and lowered vertebral fracture rates compared to placebo in 1 study. Concomitant calcium citrate therapy was given continuously in both groups throughout the treatment period.
Maximum Dosage Limits:
-Adults
Dependent upon indication and route of administration.
-Elderly
Dependent upon indication and route of administration.
-Adolescents
Dependent upon indication and route of administration.
-Children
Dependent upon indication and route of administration.
-Infants
>= 6 months: Dependent upon indication and route of administration.
< 6 months: Safe and effective use has not been established.
Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears no dosage adjustments are needed.
Patients with Renal Impairment Dosing
CrCl 20-50 ml/min: Dosage reductions are necessary to avoid excessive serum concentrations, but specific guidelines for dose adjustments are not available.
CrCl < 20 ml/min: Systemic intake of supplemental fluoride is not normally recommended.
Intermittent hemodialysis:
Systemic intake of supplemental fluoride is not normally recommended.
*non-FDA-approved indication
Aluminum Hydroxide: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain aluminum. An interval of at least 2 hours is advisable between administration of sodium fluoride and aluminum hydroxide.
Aluminum Hydroxide; Magnesium Carbonate: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain aluminum. An interval of at least 2 hours is advisable between administration of sodium fluoride and aluminum hydroxide.
Aluminum Hydroxide; Magnesium Hydroxide: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain aluminum. An interval of at least 2 hours is advisable between administration of sodium fluoride and aluminum hydroxide.
Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain aluminum. An interval of at least 2 hours is advisable between administration of sodium fluoride and aluminum hydroxide.
Aluminum Hydroxide; Magnesium Trisilicate: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain aluminum. An interval of at least 2 hours is advisable between administration of sodium fluoride and aluminum hydroxide.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium Acetate: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium Carbonate: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium Carbonate; Famotidine; Magnesium Hydroxide: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium Carbonate; Magnesium Hydroxide: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium Carbonate; Magnesium Hydroxide; Simethicone: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium Carbonate; Simethicone: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium Chloride: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium Gluconate: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Calcium; Vitamin D: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Chromium: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Food: (Major) Simultaneous oral administration of dairy foods along with sodium fluoride can produce calcium fluoride, which is poorly absorbed from the GI tract. Dairy products may also reduce fluoride absorption. While sodium fluoride may be administered with most foods to help reduce GI irritation, an interval of at least 2 hours is recommended between administration of sodium fluoride and dairy foods or other foods containing high levels of calcium.
Magnesium Salts: (Major) Absorption of sodium fluoride may be reduced by concomitant use of magnesium supplements or antacids that contain magnesium. An interval of at least 2 hours is advisable between administration of sodium fluoride and magnesium salts.
Magnesium: (Major) Absorption of sodium fluoride may be reduced by concomitant use of magnesium supplements or antacids that contain magnesium. An interval of at least 2 hours is advisable between administration of sodium fluoride and magnesium salts.
Omeprazole; Sodium Bicarbonate: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Pyridoxine, Vitamin B6: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Sodium Bicarbonate: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Sodium Sulfate; Magnesium Sulfate; Potassium Chloride: (Major) Absorption of sodium fluoride may be reduced by concomitant use of magnesium supplements or antacids that contain magnesium. An interval of at least 2 hours is advisable between administration of sodium fluoride and magnesium salts.
Trientine: (Major) In general, oral mineral supplements should not be given since they may block the oral absorption of trientine. However, iron deficiency may develop, especially in children and menstruating or pregnant women, or as a result of the low copper diet recommended for Wilson's disease. If necessary, iron may be given in short courses, but since iron and trientine each inhibit oral absorption of the other, 2 hours should elapse between administration of trientine and iron doses.
Vitamin D: (Moderate) Absorption of sodium fluoride may be reduced by concomitant use of antacids that contain magnesium, aluminum, or calcium. An interval of at least 2 hours is advisable between administration of sodium fluoride and antacids.
Fluoride replaces the hydroxyl group in the calcium phosphorus salts of teeth and bones to form fluoroapatite. Fluoride enters the systemic circulation by way of food or drink and is essential in formation of strong bones and teeth. Tooth development begins before birth and fluoride is effective in conferring caries-resistant properties in the pre- and postnatal period. Although changes can occur in the surface enamel of teeth, there is little change in their basic composition during life. A study investigated the addition of oral fluoride (1 mg/day) to pregnant women who drank fluoridated water. The resultant children were caries-free at ages 5 and 6 years. However, at this time the FDA does not recommend additional fluoride intake during pregnancy.
Fluoride available in the oral cavity also plays a part in prevention of tooth decay. Fluoride in saliva has a small bactericidal action. Saliva provides a buffering action that neutralizes plaque acids. If plaque acids are not neutralized demineralization of the tooth occurs. Once the buffering action restores plaque pH, remineralization can take place. This is the critical point at which fluoride is essential. Minerals deposited as fluoroapatite in surface tooth enamel are more resistant to erosion than hydroxyapatite. These new surfaces contain few pits and fissures, further reducing likely spots for decay.
When dentin is exposed, possibly as a result of receding gums, it is sensitive to external stimuli. Application of topical sodium fluoride allows for insoluble material to be deposited in the dental tubules, blocking the transmission of unpleasant stimuli.
Systemic administration of large doses of sodium fluoride produces dramatic increases in bone mass. The mechanism whereby fluoride is incorporated into bone is the same as for teeth. However, replacing hydroxyl groups with fluoride changes the size and structure of crystal formation. Chronic ingestion of fluoride can produce a hyperostosis, with dense bone, ligament ossification, and neurologic complications caused by bony overgrowth. In treating osteoporosis, sodium fluoride increases bone mass of the spine. This increase is offset, however, by development of non-load bearing bone in the hips, knees, feet and ankles. Although there may be a decrease in spinal fractures, there is an increased risk of fracture at these other sites, often seen as microfractures accompanied by pain. The recent study by Pak et al showed that a 2 month drug-free interval overcame the attenuated osteoblastic activity seen with continuous fluoride therapy. A continuous supplementation of calcium citrate was also given, which may inhibit parathyroid hormone secretion and reduce bone resorption. Conjunctive use of calcium and vitamin D during sodium fluoride supplementation are essential in prevention of bone mineralization defects. Calcium carbonate has been implicated in decreasing radial shaft bone density in postmenopausal osteoporosis, but the Pak study found that calcium citrate stabilized it.
Sodium fluoride is administered systemically via the oral route or applied topically to the teeth. Ionic fluoride is the pharmacologically active form and 15-20% of plasma fluoride is ionized. Once absorbed, fluoride is distributed widely and stored in bones and teeth. Fluoride can be detected in all tissues and organs throughout the body, but does not accumulate in non-calcified tissue. Saliva contains fluoride, with small amounts found in tears, sweat, and hair. Fluoride crosses the placenta and is essential to bone and tooth formation in the neonate. Fluoride is distributed into breast milk, but the concentration in milk is low (i.e., ranges from 0.007-0.011 mg/L). Skeletal tissue has a high capacity for storage of fluoride ions, and is responsible for maintaining a low concentration of fluoride in the body. Serum fluoride concentrations of 5-10 micro-mol/l are believed to be therapeutic. Teeth represent a small repository of fluoride because of their relatively small mass. Most of the fluoride in teeth is concentrated in dental enamel, and secondly at the dentinoenamel junction. Fluoride in teeth is not readily released. Excretion of fluoride is mainly renal with small amounts excreted in the feces. About 90% is filtered by the glomerulus, with reabsorption by the renal tubules.
-Route-Specific Pharmacokinetics
Oral Route
Absorption of sodium fluoride from the GI tract is rapid and almost complete.
Topical Route
Systemic absorption of fluoride from improperly used toothpaste or other topical preparation can be significant.
-Special Populations
Renal Impairment
Dialysed patients with uremia have increased serum fluoride concentrations. This may result from use of ionized water from fluoridated supplies in the dialysate bath. Water used in dialysis should be deionized prior to use because high serum concentrations of fluoride could exacerbate existing bone disease in patients with uremia.