PERIOSTAT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PERIOSTAT (PERIOSTAT).
Inhibits matrix metalloproteinases (MMPs), particularly collagenase, thereby reducing connective tissue breakdown; also has anti-inflammatory and antibacterial properties.
| Metabolism | Not extensively metabolized; excreted primarily unchanged in urine. |
| Excretion | Renal: 60% unchanged drug; fecal: 40% as unchanged and metabolites |
| Half-life | Terminal elimination half-life is 16-18 hours; clinically allows twice-daily dosing for sustained therapeutic levels |
| Protein binding | 20-30% bound to plasma proteins (primarily albumin) |
| Volume of Distribution | 1.0-1.5 L/kg; suggests moderate tissue distribution including gingival crevicular fluid |
| Bioavailability | Oral: 55-70% (with food reduces absorption); subgingival: 100% locally |
| Onset of Action | Oral: 2-3 days for reduction of gingival bleeding; subgingival controlled-release: immediate upon placement |
| Duration of Action | Oral: 24 hours with twice-daily dosing; subgingival: up to 21 days after a single application |
| Molecular Weight | Doxycycline hyclate: 512.9 Da (doxycycline base: 444.4 Da). Note: Periostat is doxycycline hyclate. |
20 mg orally twice daily
| Dosage form | CAPSULE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment; not studied in severe renal impairment (CrCl <30 mL/min) or dialysis. |
| Liver impairment | No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B); not studied in severe hepatic impairment (Child-Pugh C). |
| Pediatric use | Safety and efficacy not established in pediatric patients under 18 years. |
| Geriatric use | No specific dose adjustment recommended; use with caution due to potential for age-related renal and hepatic function decline. |
| 1st trimester | Tetracyclines are generally contraindicated in pregnancy due to risk of teratogenicity (e.g., neural tube defects) and maternal hepatotoxicity. Avoid use in first trimester unless no alternative. |
| 2nd trimester | Contraindicated: risk of fetal bone and tooth discoloration, and inhibition of bone growth. Use only if no safer alternative. |
| 3rd trimester | Contraindicated: fetal bone and tooth discoloration; may cause maternal hepatotoxicity. Avoid use. |
Clinical note
Comprehensive clinical and safety monograph for PERIOSTAT (PERIOSTAT).
| Placental transfer | Tetracyclines cross the placenta readily; fetal serum levels reach 50-70% of maternal levels. Accumulates in fetal bones and teeth. |
| Breastfeeding | Tetracyclines are excreted into breast milk in low concentrations but may cause dental staining and bone growth inhibition in nursing infants. Avoid breastfeeding during treatment; if used, consider temporary discontinuation of breastfeeding. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to doxycycline or any tetracyclinePregnancyBreastfeeding (relative, absolute per manufacturer)Children under 8 years (unless for anthrax)Severe hepatic impairment
| Precautions | Photosensitivity, Superinfection due to overgrowth of nonsusceptible organisms, Use in pregnancy (Category D) may cause fetal harm, Avoid in children under 9 years of age (may cause permanent tooth discoloration and enamel hypoplasia), Hepatic or renal impairment requires dose adjustment |
| Food/Dietary | Avoid taking with dairy products (milk, cheese, yogurt), calcium-fortified juices, antacids, or iron supplements within 2 hours before or after dosing. Food does not significantly affect absorption, but taking with a meal may reduce stomach upset. |
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| Lactation Rating | L4 (Possibly Hazardous) |
| Teratogenic Risk | Periostat (doxycycline) is a tetracycline antibiotic. First trimester: Avoid due to possible teratogenic effects (animal studies show skeletal abnormalities; human data limited but risk cannot be excluded). Second and third trimesters: Contraindicated due to permanent tooth discoloration and enamel hypoplasia in the fetus, as well as reversible inhibition of bone growth. Tetracyclines form calcium complexes in bone and teeth. |
| Fetal Monitoring | Monitor maternal liver function, renal function, and signs of hepatotoxicity (rare). No specific fetal monitoring required if exposure occurs during pregnancy, but if inadvertent use in second/third trimester, consider ultrasound for fetal bone growth and dental development assessment. In neonates exposed in utero, monitor for tooth discoloration and bone growth. |
| Fertility Effects | Doxycycline has no known clinically significant effects on human fertility. In animal studies, high doses caused reduced spermatogenesis and impaired fertility, but relevance to humans at therapeutic doses is low. |
| Clinical Pearls | Periostat (doxycycline hyclate) 20 mg is indicated as an adjunct to scaling and root planing for periodontitis. It works by inhibiting collagenase activity, not primarily as an antibiotic. Monitor for photosensitivity reactions; advise sun avoidance. Avoid use in children under 8 years and during pregnancy/lactation due to tooth discoloration and bone growth impairment. |
| Patient Advice | Take this medication exactly as prescribed, usually twice daily for at least 3 months. · Swallow the tablet whole with a full glass of water; do not crush or chew. · Avoid dairy products, antacids, or iron supplements within 2 hours of taking Periostat as they can reduce absorption. · Use sunscreen and protective clothing to prevent severe sunburn; avoid tanning beds. · Report any symptoms of persistent diarrhea, vaginal itching, or skin rash to your dentist or doctor. |