Which of the following drugs is not given for sedation, but has sedation as side effect
Phenytoin There is confusion between option 'a' i.e., Antihistamine and Antidepressant and option 'b' phenytoin. Antihistamine and andidepressant Antihistamine and antidepressants have significant sedative effect. But - They can also be used as sedatives. According to Katzung 11th/e p. 521 After major depression, anxiety disorders represent the most common application of antidepressants. A number of SSRIs and SNRIs have been approved for all the major anxiety disorders. About Antihistaminic agent Katzung says p (271) and 409. A common effect of first generation HI antagonist is sedation. The effect is sufficiently prominent with some agents to make them useful as sleep aids. Diphenhydramine and doxylamine are antihistamines will well documented CNS depressants effects ans are used as sleeping aids (should not be used. for more than two weeks). But KDT has opposite views on this (6th/e p 389) Some antihistamines (promethazine, diphenyl hydramine) some anticholinergic (hyoscine) and opioids (morphine, pethidine) have significant sedative action but are not reliable for treatment of insomnia. Phenytoin appears to be a safer option because at higher dses it causes sedation and is never used as sedative. It seems to be the more correct option. Katzung 11th/e p 305 "With phenytoin sedation usually occurs only at considerably higher levels". K.D.T. 6th/e p. 405 "At higher plasma levels phenytoin causes drowsiness".
Antihistamine and antidepressant
Phenytoin
Cyclosporine and macrolides
Amphotericin B