There are a number of factors that can influence the elimination of drug from the system. These influential factors must be considered when calculating the time for excretion of morphine.
Individual Factors: Two individuals who have taken same doses simultaneously will excrete the drug at different times. This is due to a number of factors that dictate the clearance time.
- Age:As the person ages, the body becomes less capable of efficiently performing its functions. People above the age of 65 have reported a prolonged time interval for the clearance of drug.
- Body Size: People having a larger body size tend to metabolize and excrete the drug at faster rates in comparison to individuals with a small body size. The body size is determined by height and weight of the person.
- Genetics:The genetics play an important role in regulating the functions of enzymes. Some people have a genetic composition that leads to the production of more efficient protein molecules that make up the various enzymes. Such people will exhibit a faster metabolism.
- Urinary pH: A low pH can enhance the rate of excretion while an alkaline pH can delay the process. It is due to the fact that alkaline pH promotes the reabsorption and recirculation of the drug through the body.
Frequency: A person who has taken morphine just once is more likely to clear it within a few hours duration in comparison to a person who frequently abuses morphine. This occurs because morphine tends to accumulate in the body of long-term users. Frequent users consume the second dose before their first dose has undergone excretion so it keeps adding more burden on the liver and kidneys as they work harder for metabolism and excretion.
Co-administration of drugs: There are many drugs that can enhance or inhibit the metabolism of morphine. It is due to their action on the same enzymes involved in the hepatic metabolism of morphine. The speed of metabolism becomes altered and the half-life either gets extended or reduced. Any medication in simultaneous use for any other disorder must be discussed with the doctor.
Dosages: The dosages also affect the duration morphine stays in the body for. The high doses of morphine take their toll on the health of liver and kidney. More concentration of hepatic enzymes will be needed to metabolize the heavy doses. This can even lead to an impairment of liver functions and accumulation of drug within the body.