Side Effects of Timoptic (timolol)

Timoptic, Timoptic-XE, Timoptic in Ocudose (timolol) is a beta-adrenergic blocking agent (beta-blocker) that blocks the action of the sympathetic (adrenergic) nervous system, for example, on the heart. 

In addition to its effect on the heart, timolol causes a reduction of the pressure within the eye (intraocular pressure). This effect may result from a reduction in production of the liquid (aqueous humor) within the eye. The precise mechanism of this effect is not known. The reduction in intraocular pressure reduces the risk of damage to the optic nerve and loss of vision in patients with glaucoma. 

Common side effects of Timoptic include:

• blurred vision,
• burning or stinging in the eye,
• irritation to the eye,
• pain or dryness in the eye.

Serious side effects of Timoptic are rare and may include side effects seen with oral beta-adrenergic blockers such as:

• fatigue,
• insomnia,
• nausea,
• slow heart rate,
• low blood pressure,
• cold extremities, and
• shortness of breath or wheezing.

Drug interactions of Timoptic include oral beta-adrenergic blocking agents, for example, propranolol, atenolol, metoprolol, or carvedilol taken with Timoptic can result in additive effects and patients may experience excessively low blood pressure or reductions in heart rate. Combining calcium channel blockers with Timoptic may increase the risk of abnormal heart beats.

Although there are no human studies that have examined the effects of oral timolol on the fetus, animal studies have shown adverse effects. A physician must weigh the potential risks to the fetus against the potential benefits to the mother. It is unknown if the small amount of Timoptic that penetrates into the blood after administration into the eye affects the fetus.

Concentrations of timolol in breast milk can be three times those in the mother's blood after oral administration. It is unknown how much, if any, timolol appears in breast milk after administration into the eye. Ideally, patients taking Timoptic should avoid breastfeeding.

Common side effects include:

• blurred vision, and
• burning or stinging in the eye.

Ophthalmic timolol can cause irritation to the eye which may manifest as pain or dryness in some people.

Rarely, timolol eye drops can result in side effects that are seen with other oral beta adrenergic blockers. For example, persons can experience:

• fatigue,
• insomnia,
• nausea,
• slow heart rate,
• low blood pressure,
• cold extremities, and
• shortness of breath or wheezing.

The most frequently reported adverse experiences have been burning and stinging upon instillation (approximately one in eight patients).

The following additional adverse experiences have been reported less frequently with ocular administration of this or other timolol maleate formulations:

Body As A Whole

Headache, asthenia/fatigue, and chest pain.

Cardiovascular

Bradycardia, arrhythmia, hypotension, hypertension, syncope, heart block, cerebral vascular accident, cerebral ischemia, cardiac failure, worsening of angina pectoris, palpitation, cardiac arrest, pulmonary edema, edema, claudication, Raynaud's phenomenon, and cold hands and feet.

Digestive

Nausea, diarrhea, dyspepsia, anorexia, and dry mouth.

Immunologic

Systemic lupus erythematosus.

Nervous System/Psychiatric

Dizziness, increase in signs and symptoms of myasthenia gravis, paresthesia, somnolence, insomnia, nightmares, behavioral changes and psychic disturbances including depression, confusion, hallucinations, anxiety, disorientation, nervousness, and memory loss.

Skin

Alopecia and psoriasiform rash or exacerbation of psoriasis.

Hypersensitivity

Signs and symptoms of systemic allergic reactions, including anaphylaxis, angioedema, urticaria, and localized and generalized rash.

Respiratory

Bronchospasm (predominantly in patients with preexisting bronchospastic disease), respiratory failure, dyspnea, nasal congestion, cough and upper respiratory infections.

Endocrine

Masked symptoms of hypoglycemia in diabetic patients.

Special Senses

Signs and symptoms of ocular irritation including conjunctivitis, blepharitis, keratitis, ocular pain, discharge (e.g., crusting), foreign body sensation, itching and tearing, and dry eyes; ptosis; decreased corneal sensitivity; cystoid macular edema; visual disturbances including refractive changes and diplopia; pseudopemphigoid; choroidal detachment following filtration surgery; and tinnitus.

Urogenital

Retroperitoneal fibrosis, decreased libido, impotence, and Peyronie's disease.

The following additional adverse effects have been reported in clinical experience with ORAL timolol maleate or other ORAL beta-blocking agents and may be considered potential effects of ophthalmic timolol maleate:

Allergic

Erythematous rash, fever combined with aching and sore throat, laryngospasm with respiratory distress.

Body as a Whole

Extremity pain, decreased exercise tolerance, weight loss.

Cardiovascular

Worsening of arterial insufficiency, vasodilatation.

Digestive

Gastrointestinal pain, hepatomegaly, vomiting, mesenteric arterial thrombosis, ischemic colitis.

Hematologic

Nonthrombocytopenic purpura; thrombocytopenic purpura, agranulocytosis.

Endocrine

Hyperglycemia, hypoglycemia

Skin

Pruritus, skin irritation, increased pigmentation, sweating

Musculoskeletal

Arthralgia.

Nervous System/Psychiatric

Vertigo, local weakness, diminished concentration, reversible mental depression progressing to catatonia, an acute reversible syndrome characterized by disorientation for time and place, emotional lability, slightly clouded sensorium, and decreased performance on neuropsychometrics.

Respiratory

Rales, bronchial obstruction.

Urogenital

Urination difficulties.

Although Timoptic used alone has little or no effect on pupil size, mydriasis resulting from concomitant therapy with Timoptic and epinephrine has been reported occasionally.

Beta-Adrenergic Blocking Agents

Patients who are receiving a beta-adrenergic blocking agent orally and Timoptic should be observed for potential additive effects of beta-blockade, both systemic and on intraocular pressure. The concomitant use of two topical beta-adrenergic blocking agents is not recommended.

Calcium Antagonists

Caution should be used in the coadministration of beta-adrenergic blocking agents, such as Timoptic, and oral or intravenous calcium antagonists because of possible atrioventricular conduction disturbances, left ventricular failure, and hypotension. In patients with impaired cardiac function, coadministration should be avoided.

Catecholamine-Depleting Drugs

Close observation of the patient is recommended when a beta blocker is administered to patients receiving catecholamine-depleting drugs such as reserpine, because of possible additive effects and the production of hypotension and/or marked bradycardia, which may result in vertigo, syncope, or postural hypotension.

Digitalis And Calcium Antagonists

The concomitant use of beta-adrenergic blocking agents with digitalis and calcium antagonists may have additive effects in prolonging atrioventricular conduction time.

CYP2D6 Inhibitors

Potentiated systemic beta-blockade (e.g., decreased heart rate, depression) has been reported during combined treatment with CYP2D6 inhibitors (e.g., quinidine, SSRIs) and timolol.

Clonidine

Oral beta-adrenergic blocking agents may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. There have been no reports of exacerbation of rebound hypertension with ophthalmic timolol maleate.

Injectable Epinephrine

See product packaging for more information.