CITANEST PLAIN DENTAL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CITANEST PLAIN DENTAL (CITANEST PLAIN DENTAL).
Propylocaine, an amide-type local anesthetic, stabilizes the neuronal membrane by binding to voltage-gated sodium channels, thereby inhibiting sodium influx and blocking conduction of nerve impulses.
| Metabolism | Primarily metabolized by ester hydrolysis in plasma and liver via pseudocholinesterase and carboxylesterases. |
| Excretion | Renal excretion of metabolites (primarily 4-hydroxyprilocaine and N-propylalanine) accounts for >95% of elimination; <5% excreted unchanged in urine. Less than 1% eliminated via feces. |
| Half-life | Terminal elimination half-life is approximately 1.6 hours (range 1–2 hours). This short half-life allows for rapid clearance, minimizing systemic accumulation during repeated dosing in dental procedures. |
| Protein binding | Approximately 55% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Volume of distribution is 0.8–1.0 L/kg, indicating moderate distribution to total body water. This reflects its lipid solubility and moderate tissue binding. |
| Bioavailability | Due to extensive first-pass hepatic metabolism, oral bioavailability is negligible (≈5%). For dental use, administered by injection, thus systemic bioavailability is 100% for the injected dose. |
| Onset of Action | Following submucosal injection (dental infiltration or nerve block), onset of anesthesia occurs within 1–3 minutes. |
| Duration of Action | Duration of pulpal anesthesia is 10–20 minutes for infiltration and 30–60 minutes for nerve block; soft tissue anesthesia persists longer, up to 90 minutes. Clinical note: the shorter duration compared to lidocaine makes prilocaine useful for brief procedures. |
| Molecular Weight | 220.31 Da |
Adult dose for dental anesthesia: 20-50 mg (0.5-1.25 mL of 4% solution) by infiltration; up to 200 mg (5 mL) by nerve block. Maximum dose: 6 mg/kg, not exceeding 300 mg per appointment.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment for GFR. Use with caution in severe renal impairment (GFR <30 mL/min) due to potential accumulation of metabolites; consider lower doses and extended intervals. |
| Liver impairment | Child-Pugh Class A: No adjustment. Class B: Reduce dose by 50%; maximum single dose 150 mg. Class C: Avoid use or reduce dose by 75%; maximum single dose 75 mg. |
| Pediatric use | Children: 0.5-2.5 mg/kg by infiltration; maximum dose: 4 mg/kg. Weight-based: <20 kg: 0.5-1.0 mg/kg; 20-40 kg: 1.0-1.5 mg/kg; >40 kg: up to 2.5 mg/kg. Not recommended for children under 6 months. |
| Geriatric use | Elderly: Reduce doses by 50% due to decreased tissue perfusion and increased sensitivity; maximum single dose 150 mg. Use with caution in patients with cardiovascular disease or on antiarrhythmics. |
| 1st trimester | Lidocaine is generally considered safe in pregnancy, but prilocaine has been associated with methemoglobinemia. Use only if clearly needed. |
| 2nd trimester | Similar caution: potential for methemoglobinemia with prilocaine. Use lowest effective dose. |
| 3rd trimester | Avoid near term due to risk of fetal methemoglobinemia and possible neonatal depression. |
Clinical note
Comprehensive clinical and safety monograph for CITANEST PLAIN DENTAL (CITANEST PLAIN DENTAL).
| Placental transfer | Prilocaine crosses the placenta via passive diffusion; fetal plasma concentrations are approximately 50-70% of maternal levels. Methemoglobin formation is a concern, especially with high doses or in utero near term. |
| Breastfeeding | Prilocaine enters breast milk in low concentrations; unlikely to cause adverse effects in infants. However, monitor for signs of methemoglobinemia (e.g., cyanosis) in premature or ill infants. American Academy of Pediatrics considers prilocaine compatible with breastfeeding. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to prilocaine or other amide-type local anestheticsMethemoglobinemia (acquired or congenital)Severe hypotensionCardiac conduction defects (e.g., second- or third-degree AV block without pacemaker)Severe hepatic impairmentUse in infants less than 6 months of age (risk of methemoglobinemia)
| Precautions | Avoid intravascular injection; risk of methemoglobinemia; caution in patients with hepatic impairment, methemoglobin reductase deficiency, or conditions predisposing to methemoglobinemia. |
| Food/Dietary | No specific food interactions. Avoid alcohol after dental procedure to prevent bleeding complications. |
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| Lactation Rating | L2 (Probably Compatible) |
| Teratogenic Risk | Citanest Plain Dental (prilocaine) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, but there are no adequate and well-controlled studies in pregnant women. Prilocaine crosses the placenta. First trimester: risks are minimal based on animal data. Second and third trimesters: potential for methemoglobinemia in the newborn if high doses are used or if the mother has a history of methemoglobinemia. |
| Fetal Monitoring | Monitor maternal vital signs (blood pressure, heart rate, respiratory rate) and ECG during administration. Assess for signs of local anesthetic toxicity (e.g., perioral numbness, tinnitus, metallic taste, seizures). Fetal heart rate monitoring is recommended during labor and delivery if used for obstetric anesthesia. Monitor newborn for signs of methemoglobinemia (cyanosis, hypoxia, altered mental status) if high doses were administered. |
| Fertility Effects | No specific studies have assessed fertility effects in humans. Animal studies have not shown impaired fertility at doses relevant to clinical use. Prilocaine is not known to adversely affect reproductive organs or gametogenesis. |
| Clinical Pearls |
| Citanest Plain Dental (prilocaine 4%) is an amide local anesthetic without vasoconstrictor. Maximum dose: 600 mg (15 mL of 4% solution). Onset 2-4 min, duration 30-60 min for infiltration. Risk of methemoglobinemia, especially in patients with glucose-6-phosphate dehydrogenase deficiency, anemia, or concurrent use of methemoglobin-inducing agents. Avoid use in infants <6 months. Do not inject intravascularly; aspirate before injection. |
| Patient Advice | Avoid eating or drinking until numbness wears off to prevent biting cheek or tongue. · Report any signs of allergic reaction (rash, itching, swelling) or methemoglobinemia (blue/gray skin, headache, dizziness, shortness of breath). · This product contains no epinephrine, so hemostasis is not enhanced. · Inform your dentist if you have a history of anemia, G6PD deficiency, or are taking medications like sulfonamides or nitrates. |