Drugs, Lec 8: 02/03/2014
Pharmacokinetics: Drugmovement. Made of 4 things:
Absorption: how you first get the drug into the body.
Distribution: Throughout the body. Ex. inject in one arm and measure in the other.
Vehicles: injection routes, how you can get a drug into the body. IV, inhalation, insufflation, IM, SubQ, IP,
and PO. Another injection route:
IT: intrathecal: reverse of a spinal tap. If your CSF is pink, leaking blood into ventricles. IT injection goes
into the CSF instead of your blood. Not done very often, dangerous.
IV is also dangerous because blood is sterile and infection is the most common side effect of venous
injections. Sepsis can be fatal.
IC: intracerebral. In your brain.
Can tell where a drug is acting by the distribution and absorption pattern. Look at when the drug becomes
effective, if in the first few minutes, acts locally, if after, can be anywhere.
A safer way to put drugs into CSF, is ICV: intracerebroventricular injection. Ex. ventricles are exaggerated
Transdermal: ex. nicotine patches. Inhalation is expected to be the most common way of drug
administration soon. Very effective, just as quick as IV. Ex. future studies of inhaled Prozac. Higher brain
concentration at lower doses. Less Prozac side effects. Libido is the most common side effect of
antidepressants (Erectile Dysfunction).
Suppositories: insert a drug into a body cavity, most common is rectal. A drug lasts for a very