Most adverse effects have been mild and transient and have rarely required withdrawal of therapy.
Cardiovascular: Bradycardia with heart rates of less than 60 beats per minute occurs commonly, and heart rates below 40 beats per minute and/or symptomatic bradycardia were seen in about 2 of 100 patients. Symptoms of peripheral vascular insufficiency, usually of the Raynaud type, have occurred in approximately 2 of 100 patients. Cardiac failure, hypotension, and rhythm/conduction disturbances have each occurred in about 1 of 100 patients. Single instances of first-degree and third-degree heart block have been reported; intensification of AV block is a known effect of beta-blockers (see also CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS).
Central Nervous System: Dizziness or fatigue has been reported in approximately 2 of 100 patients; paresthesias, sedation, and change in behavior have each been reported in approximately 6 of 1,000 patients.
Respiratory: Bronchospasm has been reported in approximately 1 of 1,000 patients (see CONTRAINDICATIONS and WARNINGS).
Gastrointestinal: Nausea, diarrhea, abdominal discomfort, constipation, vomiting, indigestion, anorexia, bloating, and flatulence have been reported in 1 to 5 of 1,000 patients.
Miscellaneous: Each of the following has been reported in 1 to 5 of 1,000 patients: rash; pruritus; headache; dry mouth, eyes, or skin; impotence or decreased libido; facial swelling; weight gain; slurred speech; cough; nasal stuffiness; sweating; tinnitus; blurred vision. Reversible alopecia has been reported infrequently.
The following adverse reactions have been reported in patients taking nadolol and/or other beta-adrenergic blocking agents, but no causal relationship to nadolol has been established.
Central Nervous System: Reversible mental depression progressing to catatonia; visual disturbances; hallucinations; an acute reversible syndrome characterized by disorientation for time and place, short-term memory loss, emotional lability with slightly clouded sensorium, and decreased performance on neuropsychometrics.
Gastrointestinal: Mesenteric arterial thrombosis; ischemic colitis; elevated liver enzymes.
Hematologic: Agranulocytosis; thrombocytopenic or nonthrombocytopenic purpura.
Allergic: Fever combined with aching and sore throat; laryngospasm; respiratory distress.
Miscellaneous: Pemphigoid rash; hypertensive reaction in patients with pheochromocytoma; sleep disturbances; Peyronie's disease.
The oculomucocutaneous syndrome associated with the beta-blocker practolol has not been reported with nadolol.