The short version: independent testing, conservative titration, sterile-ish technique, a written record and a clinician who knows.
Pharmacological risk is reduced by starting below the lowest licensed step and escalating more slowly than the label schedule. Time is the cheapest resource in this whole calculation.
Know the symptoms that end the discussion: severe epigastric pain radiating to the back, persistent vomiting with reduced urine output, spreading redness with fever, jaundice, chest pain or breathlessness.
Withheld information is a recognised barrier to effective clinical assessment, and disclosure changes management in a substantial fraction of cases.
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Test your own material. Everything else is downstream of knowing what it is.