56 - The correct answer is d) All of the above. Barbiturates bind to the GABA-A receptor Cl− channel complex, lead to increased GABA-mediated chloride conductance, and cause membrane hyperpolarization.
57 - The correct answer is b) Increase the frequency of opening of Cl– channels. Benzodiazepines increase the frequency of opening of Cl– channels, enhancing the inhibitory effects of GABA.
59 - The correct answer is d) All of the above. Centrally acting skeletal muscle relaxants are used in acute muscle spasms, anxiety and tension, as well as backache and neuralgias.
66 - The correct answers are b) treatment is aimed at increasing serotonin and c) it can be caused by biochemical defects. Exogenous (reactive) depression can be treated by increasing serotonin levels, and it can be caused by biochemical defects.
75 - The correct answer is d) All statements are true. Serious adverse effects of tricyclic antidepressants include liver toxicity, cardiac arrhythmias, and excess CNS stimulation.
78 - The correct answer is a) Trunk; Intercostal Muscle; Hands & Feet; Arm, Legs, Neck, Face; Diaphragm; Eyes & Fingers.
80 - The correct answer is e) only A and C are true. The main pharmacologic effects of tricyclic antidepressants on neurotransmitter activity are to increase norepinephrine and serotonin.
81 - The correct answer is d) All statements are true. The pharmacologic effects of tricyclic antidepressants include alpha-adrenergic blockade, sedative action, and anticholinergic effects.
92 - The correct answer is c) Barbiturates have a high therapeutic index. The statement "Barbiturates have a high therapeutic index" is incorrect. Barbiturates actually have a low therapeutic index, which means the difference between the effective dose and toxic dose is relatively small.