If you feel angina coming on, stop what you are doing, sit down, rest and wait until the feeling passes. If you have been given GTN (glyceryl trinitrate) tablets or spray, use as instructed. If the angina persists, you can repeat the dose of tablets or spray safely three times, once every five minutes. Resume your activities gently once the symptoms have passed. If the angina is not relieved after rest or three doses of your medication in 15 minutes, call an ambulance: dial 111 immediately. If you get angina at predictable times, use your spray or tablets a few minutes before attempting that activity. If you have angina symptoms every day, worsening angina symptoms, angina at rest or at night, or symptoms that are not relieved as easily as usual by your angina medication, keep using your medication but see your doctor within 24 hours. These can sometimes be warning signs of an impending heart attack. Source:http://www.everybody.co.nz