From the Guidelines
Yes, timolol is a beta blocker, as it belongs to the class of medications known as non-selective beta-adrenergic receptor antagonists, which means it blocks both beta-1 and beta-2 receptors in the body 1.
Key Characteristics of Timolol
- Timolol is commonly prescribed in ophthalmic form as eye drops (typically 0.25% or 0.5% solution) to treat glaucoma by reducing intraocular pressure.
- It can also be prescribed orally for conditions such as hypertension, angina, and prevention of migraine headaches, though this use is less common today.
- The medication works by blocking the effects of adrenaline (epinephrine) on beta receptors, which in the eye reduces the production of aqueous humor fluid, thereby lowering eye pressure.
- In cardiovascular applications, it reduces heart rate and blood pressure by blocking beta-1 receptors in the heart.
Important Considerations
- As with other beta blockers, timolol should be used with caution in patients with asthma, COPD, heart failure, or diabetes, as it can exacerbate these conditions.
- The choice of beta blocker for an individual patient is based primarily on pharmacokinetic and side effect criteria, as well as on physician familiarity 1.
- According to the most recent guidelines, beta-blockers are recommended to be initiated orally, in the absence of contraindications, within the first 24 hours for patients with unstable angina or non-ST-elevation myocardial infarction 1.
Dosage Information
- The usual dose for angina is 10 mg twice daily 1.
- It is essential to monitor patients during beta-blocker therapy, including frequent checks of heart rate and blood pressure, and continuous ECG monitoring, as well as auscultation for rales and bronchospasm 1.
From the FDA Drug Label
Timolol maleate is a beta1 and beta2 (non-selective) adrenergic receptor blocking agent Beta-adrenergic receptor blockade reduces cardiac output in both healthy subjects and patients with heart disease Beta-adrenergic receptor blockade in the bronchi and bronchioles results in increased airway resistance from unopposed parasympathetic activity
- Yes, timolol is a beta blocker, specifically a non-selective beta1 and beta2 adrenergic receptor blocking agent 2, 3, 3.
- Key points about timolol's mechanism of action include its ability to reduce cardiac output and increase airway resistance.
From the Research
Definition of Beta Blockers
- Beta blockers are a class of medications that block the effects of the hormone epinephrine, also known as adrenaline, and reduce the heart rate and blood pressure [(4,5)].
Characteristics of Timolol
- Timolol is a non-selective beta-blocker, meaning it blocks both beta-1 and beta-2 adrenergic receptors 5.
- It is used to treat various conditions, including glaucoma and ocular hypertension 4.
Comparison with Other Beta Blockers
- Timolol has been compared to other beta blockers, such as metoprolol, a beta-1-selective beta-blocker, in terms of its effects on exercise performance 5.
- The study found that timolol caused a greater reduction in exercise performance than metoprolol during continuous exercise 5.
Classification of Timolol
- Based on the evidence, timolol can be classified as a beta blocker, specifically a non-selective beta-blocker [(4,5)].