INBDE Pharmacology Practice Test

Barbiturates are strong CNS depressants with a real risk of respiratory depression and they can trigger metabolic conditions in susceptible individuals. Intermittent porphyria is a contraindication because barbiturates induce hepatic enzymes and increase porphyrin synthesis, precipitating acute attacks. In COPD, the already compromised airflow and gas exchange mean additional respiratory depression from barbiturates can lead to dangerous hypoventilation and hypoxemia. For undiagnosed severe pain, a barbiturate would not provide analgesia and could sedate the patient without addressing pain, potentially masking symptoms and delaying diagnosis or appropriate treatment. Taken together, all of these conditions make barbiturate use inappropriate, so the correct approach is recognizing that all of the above are contraindications.