Timolol Side Effects
Some side effects of timolol may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
For the Consumer
Applies to timolol: oral tablet
Get emergency medical help if you have any of these signs of an allergic reaction while taking timolol: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have any of these serious side effects:
slow or uneven heartbeats;
feeling light-headed, fainting;
feeling short of breath, even with mild exertion;
swelling of your ankles or feet;
nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
cold feeling in your hands and feet.
Other less serious side effects are more likely to occur, such as:
decreased sex drive, impotence, or difficulty having an orgasm;
sleep problems (insomnia);
tired feeling; or
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.
For Healthcare Professionals
Applies to timolol: compounding powder, oral tablet
Cardiovascular side effects are the most common. Sinus bradycardia is reported in 9% of patients. Atrioventricular conduction disturbances, hypotension, and exacerbation of congestive heart failure are reported in less than 1% of patients.
Respiratory problems associated with timolol, like with other beta antagonists, include bronchial constriction in susceptible patients. Dyspnea is reported in 6% of patients.
Alternative therapy should be considered in patients with reactive airways disease. Cases of fatal respiratory arrest are reported in patients with asthma, even after topically administered timolol.
Nervous system side effects include fatigue in 6%, headache in 4%, and dizziness in 6% of treated patients. Cases of visual hallucinations, insomnia and depression have been reported rarely. Timolol may worsen myasthenia gravis.
A case of amaurosis fugax is associated with timolol. However, the patient involved had underlying cerebrovascular disease, autonomic dysfunction, and an arrhythmia.
Endocrinologic side effects of timolol include masking the signs and symptoms and blunting the normal physiologic response to hypoglycemia. Timolol may cause an increase in serum triglycerides, LDL cholesterol, and VLDL cholesterol, and a decrease in HDL cholesterol.
Alternative therapy should be considered in patients with diabetes mellitus who are prone to hypoglycemia.
Psychiatric side effects, such as confusion, depression (including acute suicidal ideation), vivid and frightening dreams, and visual hallucinations are reported in rare cases.
Sexual dysfunction is reported from questionnaires, although the questions may have biased the data since the responses were not spontaneous.
Gastrointestinal complaints of general abdominal pain, nausea, constipation, or diarrhea are reported in 1% to 5% of patients.
Dermatologic side effects are unusual. Rare cases of generalized psoriasis and hyperpigmented nailbeds are reported.
Genitourinary complaints of impotence and decreased libido are rare.
Musculoskeletal side effects are rare. Timolol may worsen myasthenia gravis.
General side effects including decreased exercise tolerance, extremity pain, weight loss and fever have been reported.
Hypersensitivity reactions including anaphylaxis have been reported in clinical experience with timolol.
More timolol resources
- timolol Concise Consumer Information (Cerner Multum)
- timolol Advanced Consumer (Micromedex) - Includes Dosage Information
- timolol MedFacts Consumer Leaflet (Wolters Kluwer)
- Timolol eent Monograph (AHFS DI)
- Timolol Prescribing Information (FDA)
- Blocadren Prescribing Information (FDA)
- Timolol Maleate Monograph (AHFS DI)
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