You stop trying and find a new doctor. Any doctor who would give you a medicine that you say has caused your throat to close is a moron.
The doctor/patient relationship is based on trust.
If your doctor doesn't believe you are telling the truth, then find another doctor.
Um. Guess what. You are the patient and you know your medical history better than any copy machine. Your doctor can offer medical advice if he is not listening to you and is choosing to push a drug on you that has a history of causing your airway to close I would run like heck elsewhere.