What is the bioavailability of paracetamol?
Bioavailability of intravenous paracetamol is 100%, whereas the oral bioavailability of paracetamol can be as low as 79% [15].
What is morphine bioavailability?
The bioavailability of morphine is 80-100%. 8. There is significant first-pass metabolism, therefore oral doses are 6 times larger than parenteral doses to achieve the same effect. Morphine reaches steady-state concentrations after 24-48 hours.
Why is morphine administered slowly?
Administration of Morphine Sulfate Injection should be limited to use by those familiar with the management of respiratory depression. Morphine must be injected slowly; rapid intravenous administration may result in chest wall rigidity.
What is peak plasma concentration?
Cmax is the highest inhibitor concentration reached in the blood in vivo and is an approximation of the inhibitor concentration (I) at the enzymes in the liver. From: Drug-Like Properties (Second Edition), 2016.
How do you calculate bioavailability of a drug?
Bioavailability is calculated by comparing plasma levels of a drug given via a particular route of administration (for example, orally) with plasma drug levels achieved by IV injection. This is where the AUC comes into play (the area under the curve calculated by plotting plasma concentrations of the drug versus time).
What is bioavailability of morphine?
Absolute bioavailability for morphine was estimated to be 23.9% after oral solution, 22.4% after MST-Continus and 18.7% after the buccal tablet. Maximum plasma morphine concentrations were seen at 45 min (oral solution), 2.5 h (MST) and 6 h (buccal).
What is the bioavailability of IV morphine?
Morphine administered intravenously (8.8 mg) and by inhalation (17.6 mg) produced approximately the same maximal degree of ventilatory depression. This finding is consistent with the bioavailability value of 59%.
How does morphine affect the pharmacokinetics of paracetamol?
Conclusions: Morphine co-administration significantly impacted the pharmacokinetics of oral but not intravenous paracetamol.
How is the bioavailability of a drug calculated?
Bioavailability is calculated as AUC, or area under curve of plasma values over time. True bioavailability, or fractional absorption, is AUCoral /AUC intravenous expressed as a percentage, with 100% being maximal bioavailability.
How can bioavailability of a compound be improved?
Bioavailability of a compound can be enhanced by coadministration with an absorption enhancer. For example, administration of an isoflavone, daidzein, with a eutectic mixture of borneol/menthol results in improvement of the solubility as well as permeability of the isoflavone in isolated rat intestinal membrane.
When does bioavailability of lipid soluble substances decrease?
Lipid-soluble substances are taken up especially from sediment or from other organisms. The bioavailability from water decreases with increasing lipophilicity and with increasing amount of dissolved organic carbon or colloids in the aquatic phase.
