(c) Answer is (c)- memorization- BDZ’s bind to sites on the GABA receptor.

(b) Barbiturates are problematic as anesthetics because they often induce excessive salivation and bronchial secretion, usually requiring the use of an anticholinergic drug to be administered to reduce these secretions. Thus (b) has to be the false statement.

(d) is correct- thiopental is the classic example always given of a drug whose duration of action is determined by redistribution away from its site of action in the brain to less well perfused tissues. They leave out the word redistribution from the answer to confuse you – they know this is the way you learned it.

(c) reworded version of the question above

(b) yet another reworded version

(iii) Answer is (c)- Barbiturates are not analgesics, thus any answer with “a” such as (a) can be eliminated.. “b” is true, thus the answer must contain “b” as one of the alternatives, thus (d) and (e) are eliminated. “c” is also true, barbiturates are always classified according to duration of action (thiopental- ultra-short acting; phenobarbital-long-acting, etc.). This eliminates # 3 so the answer must be (b). Of course, you should have been able to rapidly eliminate answers (c), 4, and 5 because barbiturates cause death by respiratory depression, not cardiovascular depression.

(i) Answer is (a)- “d” is the absolute contraindication for barbiturate use, since these drugs stimulate the synthesis of enzymes involved in the synthesis of porphyrins and thus will aggravate this disease. Thus the answer must contain “d”, eliminating (c) and (d). Since both (a) and (b) differ only by alternative c, that is the second fact you must know. Barbiturates are not analgesics, but sedatives. When pain is present, they may even make the pain worse, resulting in arousal, rage and perhaps delirium in the patient. Thus, “c” would seem to be a pretty strong contraindication, making (a) the right answer.

(b) is correct. This is one of the adverse side effects of IV diazepam. None of the other alternatives apply.

(d) barbs can be lethal due to respiratory depression, so keep them breathing!

(d) while all have sedative actions and have their uses given the appropriate setting, benzodiazepines are by far the most popular now given their safety compared to the other agents. The most popular oral BDZs has been diazepam (Valium), but there is a trend recently to the ultrashort acting versions such as triazolam (Halcion).

(d) BDZs in general are great for dental sedation precisely because they present less risk of respiratory depression in comparison to barbiturates and opioids. This is an advantage shared across all the BDZs, so if you know this you don’t really have to know anything else. The others are true advantages of midazolam vs. diazepam. Midazolam is water soluble, and thus does not need to be dissolved in propylene glycol like valium – it is the solvent that cause the thrombophlebitis seen with valium injections. Midazolam also is short acting compared to valium because it does not have active metabolites like valium. Because of the above factors, statement (d) is also true.

(b) memorize, pure and simple. The only confusing one should be naloxone, since this is used to reverse the effects of Opioids. Midazolam is a BDZ, aminophylline is a theophylline derivative, and physostigmine is a cholinesterase inhibitor.