Morphine Has Properties That May Assessment

At this stage, the drug produces no more depressive effects. Morphine has different effects at various concentrations

The depressive curve is used to show the bad effect of morphine.

It shows the concenrtaion of morphine over time before it becomes toxic to the user. The margin of safety should be large to avoid toxicity / poisoning.

What is a margin of safety?

It is the distance between the desired effect and the toxic effect. Shibamoto and Bjeldanes (2009) defined safety as the freedom from danger.

Why is a bigger margin of safety better than a small one?

A bigger margin of safety is better since it will mean that the drug user would niot easily or accidentally experience the toxic effects of the drug.

Explain why each of the lines flatline at the top and why the second line also flatlines to begin with.

The flat lines that are observed on top of the analgesic and depressive curves indicate the tolerant states of the drug usage

Analgesic curve flatlines

The flatlines on top of the analgesic curve depicts the state when no further increase in dosage would increase the desired effects

Depressive curve flatlines

As for the depressive curve.The plateau depict the state when no further increase in dosage would lead to the toxic effects.

References

Beach, HD (1957).Morphine addiction in ratsCanadian Journal of Psychology/Revue canadienne de psychologie, Vol 11(2), Jun 1957, 104-112.

Jaffe JH, Martin WR. In: Gilman AG et al. (Eds).(1990) Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed. New York: Pergamon Press, 1990, pp 485-521

Mucha, H and Kalan, RF (1981)Naloxone prevention of morphine LDR curve flattening associated with high-dose tolerance

Martin WR, Fraser HF (1961). "A comparative study of physiological and subjective effects of heroin and morphine administered intravenously in postaddicts." Journal of Pharmacology and Experimental Therapeutics 133: 388 -- 99. PMID 13767429. http://jpet.aspetjournals.org/cgi/pmidlookup?view=long&pmid=13767429.

International Association for the Study of Pain (2001) Analgesic Tolerance to Opioids

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