Can morphine be given by inhalation?

RATIONALE: Morphine that is inhaled may be more rapidly absorbed than morphine that is given by mouth. It is not yet known if inhaled morphine is more effective than morphine given by mouth in relieving breakthrough pain.

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 the body distribute morphine?

Morphine is distributed throughout the body, but mainly in the kidneys, liver, lungs, and spleen. The volume of distribution is 3 or 4 l kg−1. Mean plasma elimination half-life is 1.7 h for morphine and 2.4–6.7 h for M3G. Up to 10% of a dose may eventually be excreted, as conjugates, through the bile into the feces.

How does the body absorb morphine?

Absorption. Morphine is absorbed into the bloodstream via multiple routes of administration including: Orally in the form of tablets or capsules. Rectally inside suppositories or gel-coated capsules that can be inserted into the anus so the drug can be absorbed into the rectal blood vessels.

What is the oral 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).

Does morphine have a low oral bioavailability?

Because of morphine’s high hepatic extraction ratio, the bioavailability of orally administered morphine is significantly lower than after parenteral injection.

Does morphine have a high volume of distribution?

The volume of distribution was 5.2 L/kg. Molar ratios of M3G/morphine, M6G/morphine, and M3G/M6G were 21.1, 4.7, and 4.2, respectively. Children <11 years had significantly higher clearance and larger volume of distribution for morphine and its glucuronides than older children and adults.

Is morphine absorbed?

Morphine administered nasally to humans as a simple solution is only absorbed to a limited degree, with a bioavailability of the order of 10% compared with intravenous administration.