Yes, inhalants and meth can cause
liver damage. While liver
injury makes the liver's ability to clear drugs decrease, it takes a LOT of damage before this actually matters.
Generally, the larger problem is that drug users frequently share needles for injection and frequently get
hepatitis. That is really injurious to the liver. It is now, treatable.
Meth stays in the system for about 5 days. This can be lengthened with liver disease but frankly it is more commonly due to 1)
kidney disease....it still has to get out and if the urine fitration is low, this has an effect. while the liver clearance is mainly how much blood gets to the liver (not impaired by 50% of the liver being gone), the kidney function is directly proportional to how much kidney is there. 5% less kidney 5% longer to get rid of it.
2) false readings.
AMphetamine is close to ...amphetamine. So if someone is taking ritalin/adderall/concerta/etc they are taking amphetamine and the reading will be positive for it. If they are taking ephedra,
ephedrine, psuedoephedrine, these are very close to dextroephedrine (amphetamine) and will show up as it. These are common nasal decongestants.
3) lying.
Lying will take the longest to pass a
drug test.
Liver would be unlikely to take longer than 10 days. Kidney function can be decreased by 60%, take 2 full weeks, and still be close to asymptomatic.