Products
Betaxolol is commercially available in the form of eye drops (Betoptic S). It has been approved in many countries since 1995.
Structure and properties
Betaxolol is present in drugs as betaxolol hydrochloride and racemate (C18H30ClNO3, Mr = 343.9 g/mol), a white crystalline powder that is very soluble in water. The enantiomer levobetaxolol is also commercially available in the United States in the form of eye drops.
Effects
Betaxolol (ATC C07AB05, ATC S01ED02) lowers intraocular pressure. Because it β1-selective, that is, cardioselective, it may be better tolerated in terms of pulmonary side effects than nonselective beta-blockers used in the eye. Competing products such as carteolol or timolol are nonselective.
Indications
For treatment of chronic open-angle glaucoma and elevated intraocular pressure. In the United States, but not in many countries, the agent is also approved in tablet form for oral treatment of hypertension.
Dosage
According to the drug label. Typically, 1-2 drops are placed in the conjunctival sac of the diseased eye 2 times daily.
Contraindications
- Hypersensitivity
- Bradycardia
- 2nd and 3rd degree AV block
- Cardiogenic shock
- Decompensated heart failure
For complete precautions, see the drug label.
Interactions
Pupil dilation may occur in combination with epinephrine or dipivefrin. Other interactions are possible with catecholamine-reducing drugs, adrenergic psychotropic drugs, peroral beta-blockers, and negatively inotropic or negatively chronotropic drugs.
Adverse effects
Unpleasant sensation in the eyes and eye stinging are very common. Occasionally, local eye discomfort such as lacrimation, foreign body sensation, decreased corneal sensitivity, corneal inflammation, differential pupillary dilation of both eyes, redness, or sensitivity to light occurs. Systemic side effects of beta-blockers such as cardiac arrhythmias, low blood pressure, slow pulse, headache, syncope, dizziness, asthma, or respiratory disturbances are rare.
