Drug interactions
Timolol + Tolbutamide
Severity: Moderate
Timolol and Tolbutamide: 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
Beta-blockers can mask adrenergic warning signs of hypoglycemia such as tremor and palpitations, and may prolong recovery from hypoglycemia. They can also modestly impair glycemic control.
What this interaction means in plain words
Timolol and Tolbutamide 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.
Timolol belongs to Cardiovascular; Tolbutamide belongs to Endocrine.
Why it happens
Beta-blockade suppresses sympathetic hypoglycemia symptoms and glycogenolysis, opposing sulfonylurea glucose-lowering control.
What to do
Counsel the patient that sweating may be the only warning sign, and monitor blood glucose more often. Adjust the sulfonylurea dose if needed.
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
- Albuterol + Timolol Major
- Aldesleukin + Timolol Major
- Amifostine + Timolol Major
- Amiodarone + Timolol Major
- Arformoterol + Timolol Major
Other interactions of Tolbutamide
- Glyburide-metformin + Tolbutamide Major
- Insulin degludec-liraglutide + Tolbutamide Major
- Aceclofenac + Tolbutamide Moderate
- Acemetacin + Tolbutamide Moderate
- Acetylsalicylic acid + Tolbutamide Moderate
- Albiglutide + Tolbutamide Moderate
Frequently asked questions
Can I take Timolol with Tolbutamide?
MediHelp rates the interaction as moderate. Timolol and Tolbutamide 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. Beta-blockers can mask adrenergic warning signs of hypoglycemia such as tremor and palpitations, and may prolong recovery from hypoglycemia. They can also modestly impair glycemic control.
How serious is the interaction between Timolol and Tolbutamide?
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 the patient that sweating may be the only warning sign, and monitor blood glucose more often. Adjust the sulfonylurea dose if needed.
What other medicines interact with Timolol?
MediHelp also lists interactions of Timolol with, for example, Acebutolol, Albuterol, Aldesleukin. The full list is on the Timolol page.
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