There a number of factors that determine the time diazepam stays in the system of the user such as:
If two people take the same amount of diazepam simultaneously, it is highly likely that one of them will clear it faster than the other. There are a number of factors that influence the clearance rate of Valium such as age, body mass, genetics, overall health etc.
- Age: Studies have proved that younger people are able to metabolize and excrete benzodiazepines such as Valium at a faster rate compared to older people (usually 65+). On average, the half life of drug is doubled in older individuals.
- Body mass index (BMI): The body mass as well as the fat content of a person can influence the clearance rate of the drug. People with greater body mass exhibit a faster clearance rate compared to small people. On the other hand, people with higher fat content significantly longer to remove the drug. Diazepam is a fat soluble substance so it gets accumulated into the fatty tissues of the body. Unlike people with normal body fat who take 9 days for the complete removal of the drug from plasma, obese people can take up to 19 days.
- Genetic makeup:There are a number of enzymes present in the liver that are responsible for the metabolism of diazepam. Genetics of a person influence the expression of these enzymes. So, in individuals, with faulty expression of these genes, the metabolism of diazepam can be significantly different. Such individuals tend to accumulate the drug that takes longer to leave the body.
- Basal metabolic rate (BMR):The clearance rate of a drug is influenced by the metabolic rate of a person. People with active metabolism exhibit a faster clearance rate compared to people with low BMR.
- Liver function/overall health:Since liver is the main organ involved in the metabolism and clearance of the drug, it significantly influences the time taken for its removal. People with hepatic impairment or cirrhotic liver show a longer period of clearance. It is estimated that people with liver cirrhosis may take 5 times the duration taken in people with a healthy liver. So compared to 32 hours, half life is elongated to 164 hours in cirrhotic patients.
Duration of use:
Greater the duration the drug was abused for, the longer it will for its removal. With a prolonged use, the amount of drug accumulated in the body also increases so after its use has stopped, it takes some time for its release and removal.
Dose and frequency of abuse:
If higher doses of the drug are taken frequently, the clearance period will be prolonged. It is because when high amounts of the drug are administrated in the body, the liver has to work harder to remove them. Over time, its efficiency is reduced. Also, greater doses result into greater accumulation of the drug in the body that take some time to be removed after drug use is quit.
Taking diazepam in combination with other substances can stimulate or hamper the clearance process. Some drugs may stimulate the function of liver enzymes while the others can slow down their activity resulting into a change in clearance rate. Some drugs that inhibit liver enzymes are: Chloramphenicol, Luvox, Moclobemide, Prozac, Clarithromycin, Cobicistat, Indinavir, Ketoconazole, and Ritonavir.
On the other hand, the enzyme inducer drugs are: Carbamazepine, Oxcarbazepine, Phenytoin, Rifampicin, and St. John’s wort.