Which of the following is an injectable anesthetic agent?

• A. Ketamine
• B. Pentobarbital
• C. Propofol
• D. Lidocaine

Answer: (B)

Injectable anesthetic agents are drugs given by injection to produce general anesthesia. Pentobarbital, a barbiturate, depresses the central nervous system when injected, leading to loss of consciousness and surgical anesthesia. It is a classic choice used in laboratory animals for anesthesia (and at higher doses for euthanasia), which is why it is the best answer here. Lidocaine is a local anesthetic used to numb a specific area, not to achieve full-body anesthesia. Ketamine and propofol are also injectables used to induce anesthesia, but in the context of this question, pentobarbital is the most conventional injectable anesthetic agent.