I am getting desperate I have had an abcess on a broken root canal.The tooth is due to be rem oved next wednesday.I had one couse of amoxil which didn't work so lived on painkillers then 5 day corse of metronidazole which started to work and abcess greatly reduced but not gone.I rang dentist who said there was prob residual infectiona and I could collect a further prescription to finally zap it.I just grabbed the prescription from the reception and didn't look at it and when I got home it was amoxil again I rang them and they said as most infection had gone 5 days of amoxil would be enough I thought I would have needed firther metronidazole but they said amoxil fine.I have been taking them 2 and a bit days and the abcess is back as bad as ever!I have been up all night in pain again.Do you think I can demand further metron ?