In acute intermittent porphyria, which intravenous anesthetic class is contraindicated?

In acute intermittent porphyria, which intravenous anesthetic class is contraindicated?

• A. Barbiturates
• B. Volatile anesthetics
• C. Ketamine
• D. Propofol

Answer: (A)

In acute intermittent porphyria, drugs that push the liver to increase heme synthesis can trigger neurovisceral attacks by escalating levels of toxic porphyrin precursors. Barbiturates are strong inducers of hepatic enzymes, which markedly increases ALA synthase activity and drives the porphyrin pathway toward excess precursors. That makes them contraindicated in this condition. Other commonly used anesthetic options, such as propofol, ketamine, and volatile inhaled agents, do not significantly provoke ALA synthase induction and are generally considered safer choices for porphyria patients, though care should be individualized and guided by current porphyria safety lists. If an attack occurs, treatment with hemin can suppress ALA synthase and help halt the progression of symptoms.

In acute intermittent porphyria, drugs that push the liver to increase heme synthesis can trigger neurovisceral attacks by escalating levels of toxic porphyrin precursors. Barbiturates are strong inducers of hepatic enzymes, which markedly increases ALA synthase activity and drives the porphyrin pathway toward excess precursors. That makes them contraindicated in this condition.

Other commonly used anesthetic options, such as propofol, ketamine, and volatile inhaled agents, do not significantly provoke ALA synthase induction and are generally considered safer choices for porphyria patients, though care should be individualized and guided by current porphyria safety lists. If an attack occurs, treatment with hemin can suppress ALA synthase and help halt the progression of symptoms.