A drug company manufactured a drug used for the treatment of multiple sclerosis (MS), which also contained an ingredient that was effective in treating MS in virtually everyone who took the drug but had the side effect of causing complete blindness in a small percentage of patients. The drug com­pany continued to market the drug for five years without a warning of the side effect, even though it knew or should have known of the side effect throughout this time. In the sixth year, the drug company began publishing a warning of the side effect in the Physician's Desk Reference and also in package inserts. Before the drug company began putting the warnings in the packages, a doctor prescribed the drug to his patient. Due to taking the drug, the patient went blind. The patient sued the drug company on a theory of strict product liability.

On these facts, what the patient will probably be able to prove that the drug is defective. Discuss.