做完膝部手術后膝蓋一直疼，能用什么止疼藥

今天的這段對話，在討論止疼，
 
做完膝部手術后膝蓋一直疼，能用什么止疼藥
 
來聽今天的講解:
 
A:How can I help you today?
 
我今天能幫你點什么？
 
B:I am in a lot of pain from my knee surgery last week and I need some stronger medicine.
 
我上周做完膝部手術后，膝蓋就一直疼，我需要一些更強效的藥。
 
A:The painkillers I prescribed for you are not working?
 
我給你開的止疼藥不管用嗎？
 
B:They only take the edge off for an hour or two.After that,the pain returns.
 
止疼藥只能維持一到兩個小時。過后，又開始痛了。
 
A:Well,right now you are taking a very mild painkiller.If it's not helping,I can give you something else.
 
好吧，現在你服用的是一種非常溫和的止疼藥。如果不起作用，我再給你開一些別的藥。
 
B:How about morphine?
嗎啡怎么樣？
 
A:We only prescribe morphine in extreme cases.There is another good medicine I will prescribe for you.
 
我們只有在極其特殊的情況下才會開嗎啡。我會給你開另一種有效的藥。
 
B:Oh,I didn't know that.I'll try whatever you recommend.
 
哦，我不懂這些。你說什么，我都會試試。