Propranolol can lower both heart rate and BP, so 10 mg three times daily is not automatically safe when your BP is already low. The dose depends on your pulse, BP, asthma history and reason for treatment; do not start or change it without the prescribing doctor's advice.
Record BP and pulse before doses. Seek urgent care for fainting, chest pain, severe breathlessness, confusion or a very slow pulse.
Next Steps
Share your exact BP and pulse readings, prescription and medical history with a doctor before taking the next dose. Book a Practo consultation for safe dose adjustment.