Drug interactions
Chlorpropamide + Timolol
Severity: Moderate
Chlorpropamide and Timolol: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Non-selective beta-blockers such as timolol can mask adrenergic warning symptoms of hypoglycemia, such as tremor and tachycardia, and may prolong recovery. They can also modestly impair glucose control in diabetic patients on sulfonylureas.
What this interaction means in plain words
Chlorpropamide and Timolol can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Chlorpropamide belongs to Endocrine; Timolol belongs to Cardiovascular.
Why it happens
Beta-adrenergic blockade suppresses hypoglycemia symptoms and glycogenolysis-mediated glucose recovery.
What to do
Counsel patients that sweating may be the main warning sign, and monitor blood glucose closely. Chlorpropamide has a long half-life, so hypoglycemia may be prolonged.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Timolol
- Acebutolol + Timolol Major
- Aldesleukin + Timolol Major
- Amifostine + Timolol Major
- Amiodarone + Timolol Major
- Arformoterol + Timolol Major
- Atenolol-chlorthalidone + Timolol Major
Other interactions of Chlorpropamide
Frequently asked questions
Can I take Chlorpropamide with Timolol?
MediHelp rates the interaction as moderate. Chlorpropamide and Timolol can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Non-selective beta-blockers such as timolol can mask adrenergic warning symptoms of hypoglycemia, such as tremor and tachycardia, and may prolong recovery. They can also modestly impair glucose control in diabetic patients on sulfonylureas.
How serious is the interaction between Chlorpropamide and Timolol?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Counsel patients that sweating may be the main warning sign, and monitor blood glucose closely. Chlorpropamide has a long half-life, so hypoglycemia may be prolonged.
What other medicines interact with Timolol?
MediHelp also lists interactions of Timolol with, for example, Acebutolol, Aldesleukin, Amifostine. The full list is on the Timolol page.
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