If pseudocholinesterase is absent, what condition is expected?

• A. Prolonged paralysis and apnea
• B. Muscle tremor
• C. Hypotension
• D. Seizures

Answer: (A)

Pseudocholinesterase normally breaks down succinylcholine in the blood. When this enzyme is absent or markedly reduced, succinylcholine remains active at the neuromuscular junction for a much longer time, causing a prolonged depolarizing block of skeletal muscles. The result is extended paralysis, including the muscles needed for breathing, leading to prolonged apnea until the drug is cleared from the body. This is a known inherited sensitivity to succinylcholine. Tremor, low blood pressure, or seizures aren’t the direct consequences of lacking this enzyme, so they don’t fit as the expected outcome.