KERLONE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for KERLONE (KERLONE).
Selective beta-1 adrenergic receptor antagonist; reduces heart rate, myocardial contractility, and blood pressure.
| Metabolism | Hepatic metabolism via CYP2D6; active metabolite (4-hydroxybetaxolol). |
| Excretion | Primarily renal excretion of unchanged drug and metabolites (70-80% unchanged; 20-30% as glucuronide or sulfate conjugates). Biliary/fecal excretion accounts for less than 5%. |
| Half-life | Terminal elimination half-life is 8-12 hours in healthy adults; may extend to 15-20 hours in renal impairment (CrCl <30 mL/min). |
| Protein binding | ~75% bound to albumin. |
| Volume of Distribution | 3-4 L/kg, suggesting extensive extravascular distribution. |
| Bioavailability | Oral: 70-80% (due to first-pass metabolism). |
| Onset of Action | Oral: 1-2 hours (beta-blockade effect). Intravenous: within 5 minutes. |
| Duration of Action | Oral: 24 hours (once-daily dosing maintains therapeutic effect). Intravenous: 6-8 hours. |
10 mg orally once daily; may increase to 20 mg once daily if needed. Maximum 20 mg/day.
| Dosage form | TABLET |
| Renal impairment | CrCl 30-60 mL/min: 5 mg once daily. CrCl <30 mL/min: 2.5 mg once daily. |
| Liver impairment | Child-Pugh Class A: 5 mg once daily. Child-Pugh Class B or C: 2.5 mg once daily. |
| Pediatric use | Not recommended for use in pediatric patients due to lack of safety and efficacy data. |
| Geriatric use | Initiate at 5 mg once daily; titrate cautiously based on response and tolerability. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for KERLONE (KERLONE).
| Breastfeeding | Betaxolol is excreted into breast milk in small amounts (M/P ratio approximately 0.86 orally, unknown for ophthalmic use). The relative infant dose is low, but caution is advised due to potential for bradycardia and hypoglycemia in neonates. Monitor infant for signs of beta-blockade. |
| Teratogenic Risk | First trimester: beta-blockers are associated with a small increased risk of congenital malformations, particularly cardiovascular defects, though data for betaxolol specifically are limited. Second/third trimester: may cause fetal bradycardia, intrauterine growth restriction, and neonatal beta-blockade effects (hypoglycemia, bradycardia, hypotension). Avoid use near term due to risk of neonatal complications. |
■ FDA Black Box Warning
None.
| Serious Effects |
Sinus bradycardia, heart block greater than first degree, cardiogenic shock, overt cardiac failure, hypersensitivity to betaxolol.
| Precautions | Abrupt discontinuation may exacerbate angina or precipitate MI; bronchospasm in patients with COPD/asthma; bradycardia; heart failure; diabetes (masks hypoglycemia); peripheral vascular disease; thyroid toxicity (masks hyperthyroidism). |
Loading safety data…
| Fetal Monitoring | Monitor maternal blood pressure and heart rate; fetal heart rate and growth via ultrasound; neonatal monitoring for bradycardia, hypoglycemia, and respiratory depression at delivery. |
| Fertility Effects | No specific data on betaxolol. Beta-blockers as a class may cause transient decreased libido and erectile dysfunction in males, but definitive effects on fertility are not established. |