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 pre-existing bronchospastic disease), respiratory failure, dyspnea, nasal congestion, cough and upper respiratory infections. ENDOCRINE Masked symptoms of hypoglycemia in diabetic patients (see WARNINGS). 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 (see PRECAUTIONS, GENERAL); 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.