Page 53 - Phytochemistry 2 (06-PG 605)

Pharmacological action and uses
The pharmacological activity of opium is due to the alkaloid morphine which
acts first as stimulating then depressant to the central nervous system and
respiratory centers.

 Opium is not as effective as morphine because of its slower absorption, but
it has a greater constipating action and is thus better used in antidiarrheal
preparations :Tincture opii camphorata (Elixir paregoric).

 Opium also exerts a valuable expectorant action ( Dover’s powder ).
 Morphine: powerful analgesic drug.(pain-killer)
 Codeine: is much weaker in action than morphine, development of tolerance

and addiction is less. It is mainly used to relief dry initiating cough.
 Papaverine: is chiefly used as smooth muscle relaxant especially in

bronchial asthma, arterial spasm and intestinal colic.
 Narcotine: is effective cough sedative,
 Apomorphine: has little depressant action on CNS, but is an effective as

emetic, expectorant and aphrodisiac.

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