propranolol works within 30 to 60 minutes for anxiety. It is also used to treat arrhythmias, high blood pressure, and to reduce the frequency of angina attacks. The drug is available in the form of fast-acting oral tablets, at a concentration of 10 mg, 20 mg, and 40 mg.Oral capsules of 60 mg, 80 mg, 120 mg, and 160 mg.Intravenous injection, at a concentration of 1 mg/ml.