Hi, welcome to the pharmacology course by Lecturio.
This lecture and this course is about toxicology
and we're going to cover some of the drugs of abuse
that are common in our culture.
The first group of drugs that we'll talk about
are the sedative hypnotics.
This includes the benzodiazepine, the barbiturates
and the ethanol.
With respect to benzodiazepines,
they often end in -lam or -pam.
So, rhohypnol is probably the most commonly abused of these
drugs. It is no longer used in clinical practice.
It is often referred to as the date rape drug.
It's also called a "roofie".
Chloral hydrate is a very old benzodiazepine
that we sometimes use in senior citizens,
but it is often abused in clinical practice.
It's known as "sparkle" or "floral chloral" or "flower",
which is a play on words of the name itself.
GHB, are also called "roofies", but they are called "roofies"
incorrectly because they are different from rhohypnol.
GHB is often used as a club drug.
You get euphoria, enhanced sensory perception and amnesia
and it is also sometimes used in date rape.
The other benzodiazepines are more clinically used
and I've listed them here so that
you can have them for reference.
In terms of how they affect the human body,
they are used predominantly for anti-anxiety,
and there's antidepressants as well.
They may follow the dopaminergic method of addiction.
And benzos are often used with alcohol
in the "date rape" phenomenon.
Depressant effects are potentiated
by marijuana, opioids and antipsychotics.
And in terms of the symptoms, they are similar to ethanol
with a rapid pulse and dilated pupils.
The antidote to all benzos is flumazenil. And it's often kept
in code cards and it's often kept in addiction centers.
Withdrawal treatment is usually switching them
to a longer acting benzodiazepine,
and this gives them reduced seizure activity and it gives us an
ability to gradually reduce the dose with a minimum side effects.
Diazepam is probably one of the most commonly used long
acting agent to get people off of these short acting benzos.
Sometimes we give a beta blocker too.
So, propranolol is sometimes used
to reduce the sympathetic activity
associated with benzo withdrawal.
Therapeutic withdrawal symptoms include
weight loss, paresthesia and headaches
and these also are treated with commonly over the counter
pain medications and headache medications.
Barbiturates are generally thought of as more potent and
more dangerous than benzodiazepines.
The short acting barbiturates like secobarbital
are very very addictive.
And they act through inhibiting GABA or gamma-amino butyric
acid. In medical practice, it's replaced by benzodiazepines
in terms of treating anxiety, but we still sometimes
use barbiturates in anticonvulsant therapy.
And it's often used in euthanasia
and in illegal interrogation.
Now, what's concerning about secobarbital is that it is
very commonly abused by physicians and nurses.
So, if you start to see this kind of behaviour in a
healthcare practitioner, start thinking about secobarbital.
Withdrawal treatment. Use a long acting benzodiazepine to
reduce seizure activity and give a gradual reduction of dose.
So, the treatment is going to be
exactly the same as benzo overdoses.
So, diazepam, also called valium, is a long benzo
and I mentioned that to you before.
Once again, we'll use propranolol to reduce the
sympathetic activity of withdrawal.
Now, one of the things that we have to be very aware of and we've
talked about this in our pharmacology pharmacokinetics course
is that it may induce CYP2C9. So, co-administration with
codeine can actually have lethal effects of the codeine
when patients also take barbiturates.