Reports > Death Disguised > CHAPTER SEVEN - Drugs >
Morphine and Diamorphine
| 7.6 |
Diamorphine is twice as potent as morphine, when given by intravenous injection; however, once introduced into the body, diamorphine is very rapidly changed into morphine. It is not, therefore, possible to say, as a result of toxicological tests alone, whether any morphine found on testing was originally administered as morphine or diamorphine. In Shipman's case, the overwhelming likelihood is that, during his years in Hyde, diamorphine was his drug of choice. This is apparent from the available evidence about Shipman's acquisition of controlled drugs during the 1990s, which will be discussed in Chapter Eight.
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| 7.7 |
Professor McQuay explained that morphine works by binding to the receptors which carry messages of pain to the brain. Although it has the same chemical constituents as morphine, diamorphine's different structure means that it cannot bind to the receptors and has to break down into morphine in order to be able to do so. The process of change from diamorphine to morphine takes only about 30 seconds. Dr Grenville pointed out that morphine also has euphoriant and vasodilatory effects, which can be helpful in treating certain conditions.
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| 7.8 |
Whether administered as morphine or diamorphine, the morphine has to be transported in the bloodstream to the brain and the spinal cord, where the receptors are situated. The quickest way to achieve this is by intravenous injection, i.e. administration straight into the bloodstream. Alternatively, the drug can be administered by intramuscular injection, which is much slower because the morphine has to pass from the muscle to the bloodstream before being carried to the receptors. If the drug is taken orally, then it is absorbed from the intestines into the bloodstream, before passing round to the brain and the spinal cord, and this takes longer than either the intravenous or the intramuscular route. The timing of the effects produced by the administration of morphine and diamorphine by different routes is compared at paragraphs 7.29 to 7.36.
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Drugs
