PENTOLAIR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PENTOLAIR (PENTOLAIR).
Pentolair is an ophthalmic solution containing tetracaine, a local anesthetic that blocks sodium ion channels in nerve membranes, inhibiting nerve impulse conduction and providing local anesthesia.
| Metabolism | Tetracaine is metabolized primarily by plasma cholinesterase (pseudocholinesterase) and hepatic esterases. |
| Excretion | Primarily renal excretion of unchanged drug (approximately 60-70% of the dose) via glomerular filtration and active tubular secretion. Hepatic metabolism accounts for about 20-30%, with metabolites excreted in bile and feces (10-20%). |
| Half-life | Terminal elimination half-life is approximately 2-4 hours in adults with normal renal function; prolongation to 8-24 hours in severe renal impairment (CrCl <30 mL/min). |
| Protein binding | Approximately 85-90% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.8-1.5 L/kg, indicating extensive distribution into total body water and tissues. |
| Bioavailability | Oral: 40-60% due to first-pass metabolism; intramuscular: approximately 90%. |
| Onset of Action | Intravenous: within 5-10 minutes; intramuscular: 15-30 minutes; oral: 1-2 hours. |
| Duration of Action | Intravenous: 4-6 hours; intramuscular: 6-8 hours; oral: 6-12 hours. Duration is prolonged in renal impairment. |
5 mg subcutaneously every 4 hours as needed for breakthrough pain.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | GFR 30-89 mL/min: no adjustment. GFR 15-29 mL/min: reduce dose by 25%. GFR <15 mL/min: consider alternative therapy. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: contraindicated. |
| Pediatric use | 0.2 mg/kg subcutaneously every 4-6 hours as needed, maximum 15 mg/dose. |
| Geriatric use | Start at 3 mg subcutaneously every 6 hours; titrate cautiously due to increased sensitivity and risk of adverse effects. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PENTOLAIR (PENTOLAIR).
| Breastfeeding | Timolol is excreted into breast milk in small amounts. M/P ratio unknown. Systemic absorption from eye drops is minimal, but monitor infant for signs of beta-blockade (bradycardia, hypotension). Use with caution; benefit should outweigh risk. |
| Teratogenic Risk | PENTOLAIR (timolol ophthalmic solution) is an ophthalmic beta-blocker. In pregnancy, systemic absorption is low but possible. First trimester: Limited human data, risk cannot be excluded; animal studies show no teratogenicity at high doses. Second and third trimesters: Potential fetal bradycardia and growth restriction due to beta-blockade; avoid use if possible, especially near term. |
■ FDA Black Box Warning
None.
| Common Effects | Eye irritation Foreign body sensation in eyes Blurred vision Eye itching Stinging in the eyes Increased intraocular pressure Burning sensation in eye |
| Serious Effects |
Hypersensitivity to tetracaine or other ester-type anesthetics, hypersensitivity to p-aminobenzoic acid (PABA) or its derivatives, concurrent use with other anesthetics or drugs that may enhance toxicity.
| Precautions | Prolonged use may cause corneal epithelial damage, keratitis, or corneal ulceration. Avoid use in patients with known hypersensitivity to ester-type anesthetics or p-aminobenzoic acid derivatives. Use with caution in patients with cardiac disease or hyperthyroidism due to potential systemic absorption. |
Loading safety data…
| Fetal Monitoring | Maternal: heart rate, blood pressure, signs of bronchospasm. Fetal: heart rate (bradycardia risk), growth ultrasound if prolonged use. Neonatal: monitor for bradycardia and respiratory depression after delivery if used near term. |
| Fertility Effects | Systemic beta-blockers may rarely impair erectile function; no significant effect on female fertility reported. Ophthalmic use unlikely to affect fertility. |