The effects of morphine, diacetylmorphine and some related alkaloids upon the alimentary tract: Part III. Caecum and colon

Abstract

1. The effects of morphine, heroin, codeine, dilaudid, dicodid and eukadol upon the caecum and colon are described.2. Small quantities of morphine produce a rapid increase in tone and amplitude of movements lasting many hours. Large doses result in a spastic contraction of the intestine with diminution of peristaltic movements.3. The effects of heroin closely resemble those of morphine; it usually produces a greater increase in tone than morphine but the movements are not so great. Heroin is about 30% more active than morphine.4. Codeine appears to be the weakest member of the series. It causes a slight increase in tone and peristaltic movements which never last very long.5. Dilaudid produces effects which closely resemble those of morphine and heroin but it is approximately 7.5 times more potent than morphine. Intestinal tone is increased at first but may be subnormal at the 3 or 4 hr. stage. The maximum amplitude of peristaltic movements is seen at the 3 hr. stage.6. Dicodid increases the tone, and particularly the peristaltic movements. The effects upon the general tone are moderate, much less than those of morphine, heroin or dilaudid. The increase in the amplitude of the movements is, however, much greater than with any other of the drugs. It differs from the others in producing its effects only after a long latent interval of 1–2 hr.7. Eukadol increases the peristaltic movements in a marked way and is more active in this respect than either morphine or heroin, but is inferior to dicodid. Its effects upon tone are very transient and never very marked.8. The effects of all these drugs upon the tone and peristaltic movements are at once abolished by adrenalin or atropine. Except morphine and eukadol, these drugs failed to produce their effects when administered after full doses of atropine.9. The injection of hypophysin during the phase of increased muscular activity following the injection of these drugs, always causes an immediate abolition or diminution of the peristaltic movements and loss of tone to a subnormal level. There is however a rapid recovery from this state and approximately 5–10 min. later the movements are increased to an amplitude far in excess of that seen perior to the injection of hypophysin.