How serious is it if you have a succinylcholine family allergy?

Important: I don't think you have a family "allergy" as much as a deficiency in the enzyme that breaks down succinylcholine, (pseudocholinesterase) which can occur quite commonly. It is IMPERATIVE that you tell your anesthesia provider this information. They can either use an alternative drug, or use succinylcholine and know that it would work longer. You can be tested to know if you have this problem.