Amphetamines Amphetamines egAmphetamine methamphetamineare a group of synthetic indirectacting sympathomimetic drugs that cause the release of endogenous biogenic amines such as dopamine ID: 935472
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Slide1
Drug
Abuse 2
Slide23.CNS Stimulants
Amphetamines
:
Amphetamines (
e.g.Amphetamine
, methamphetamine)are a group of synthetic, indirect-acting
sympathomimetic
drugs that cause the release of endogenous biogenic amines, such as dopamine
They are taken orally, sniffed
, smoked
or injected.
Amphetamines are
neurotoxic
& can cause tachycardia ,
dysrhythmias
& hypertensive crisis.
Withdrawal consists of
dysphoria
, drowsiness (in some cases, insomnia), and general irritability.
Khat
(Catha
edulis
) chewing leaves present in Yemen, Ethiopia & Somalia.
Khat
contains amphetamine-like agents (
cathine
&
cathinone
) with
psychostimulant
effects. It produces sense of well being, improvement of socialization, increase libido & increase work performance. It increases incidence of oral cancer.
Slide3Khat
leaves
Slide4Slide5Cocaine
:
The prevalence of cocaine abuse has increased greatly over the past decades and now represents a major public health problem worldwide. Cocaine is highly addictive
Cocaine is an alkaloid found in the leaves of
E. coca.
It was used as a local anesthetic and to dilate pupils in ophthalmology
Cocaine blocks the uptake of dopamine,
noradrenaline
, and
serotonin.
Given IV or by sniffing: a rapid stimulating effects similar to amphetamine.
It causes toxic psychosis & ulceration of the nasal mucosa& Other serious side effects.
Slide6Slide7Slide8Nicotine:
Nicotine is selective agonist of the nicotinic acetylcholine receptor .
In terms of numbers affected, addiction to nicotine exceeds all other forms of addiction.
Nicotine exposure occurs primarily through smoking of tobacco, which causes associated diseases that are responsible for many preventable deaths. The chronic use of chewing tobacco and snuff tobacco is also addicting.
Smoking-associated diseases
:include lung cancer, heart disease, atherosclerosis, laryngeal cancer, oral cancer,
oesophageal
cancer, COPD, intrauterine growth retardation & low birth weight.
Slide9Tolerance
: very quick perhaps due to desensitization of receptors.
withdrawal
syndrome
: craving
! increased
irritability, anxiety, impaired performance of psychomotor tasks, aggressiveness ,sleep disturbance
s
, headache and increased appetite.
highly addictive
with the very strong psychological component.
Slide10Treatment of nicotine dependence
Most smokers would like to quit but few succeed
Combination of psychological and pharmacological treatment achieve success rate about 25% (after 1 year)
.
Nicotine replacement therapy: Nicotine in patches (controlled release), chewing gums, nasal sprays several times daily (short effect)
Adjunct therapy
:
Bupropion
: an
antideprssant
that
reduces the severity of nicotine cravings and withdrawal symptoms .It
inhibits
the reuptake of dopamine and so increase dopamine activity in nucleus a
c
cumebens
.
Treatment course lasts for seven to twelve weeks
.
Clonidine
– rarely used due to the side-effects (hypotension, drowsiness…)
.
Slide11Cannabis
and Cannabinoids
Extracts of the hemp plant (
Cannabis
sativa,Canabis
indica
)
Cannabis mostly smoked produces a sensation of relaxation & well-being.
Cannabis contains chemicals called
cannabinoids
.One of these, delta-9-tetrahydrocannabinol (THC), is believed to be responsible for most of the characteristic psychoactive effects of cannabis.
Marijuana
: (
dried leaves and flower heads)
is one of the most frequently encountered illicit(illegal) drug worldwide.
Hashish
:
consists of the THC-rich resinous material of the cannabis plant, which is collected, dried, and then compressed into a variety of forms, such as balls, cakes
.
Their
CNS effects
are
combination of
psychotomimetic
& depressant effects
eg
: relaxation, well-being and euphoria ,uncontrolled laughing ,a feeling sharpened sensory awareness, with tastes, sounds and sights more intense and fantastic ,impairment of motor coordination (driving), impaired short-term memory and judgement, increased
appetite ,
analgesic effect
,antiemetic effect.
Slide12Slide13Slide14Mechanism of action
is through
cannabinoid
(CB) receptors
(
CB
1
- brain ) highly abundant in: hippocampus (memory), cerebellum (loss of coordination), and
substantia
nigra
(motor disturbances), hypothalamus (appetite) and
mesoli
m
bic
dopaminergic
pathway (reward) and cortex.
The synthetic
9
-THC analog
dronabinol
is approved
cannabinoid
agonist currently marketed in the USA and some European
countries for the treatment of anorexia in AIDS patients, as well as for refractory nausea and vomiting of patients undergoing chemotherapy.
Nabilone
, an older
9
-THC analog used as an antiemetic and as an adjunct analgesic for neuropathic pain.
Tolerance and physical dependence occur only to a minor degree in heavy users
. Withdrawal
syndrome: weak and usually mild irritability, restlessness, confusion, sweating tremor and sleep disturbances.
Rimonabant
is selective CB1receptor blocker used as an anorectic anti-obesity drug It can opposite effects of
cannabinoids
.
5.Hallucinogens
Hallucinogens are substances produce changes in perception, thought and mood.
Thoughts and perceptions tend to become distorted and dream-like, colours and sounds are more sharp
. Different kind of hallucinations (visual, auditory, tactile and olfactory) appear.
Thought
process tend to be illogical and disconnected
Lysergic acid diethylamide (
LSD
) is the most potent hallucinogen (agonist at 5-HT
2
receptors) .Others include:
Psilocybin,Mescaline
( agonists at 5-HT
2
receptors)
MDMA
(
Methylenedioxymethamphetamine
) (
Ecstasy
)called as "street" or "party" drug. It is an amphetamine derivative which acts mainly by inhibiting 5-HT uptake and has powerful
psychostimulant
effects typical of amphetamines, as well as
psychotomimetic
effects.
Phencyclidine called as “angel dust” and
ketamine
are
antagonists at NMDA(N-methyl-D-aspartic acid)-type glutamate receptors.
Slide16Slide176.Inhalants
Inhalants are a diverse group of substances that include volatile solvents, gases, and nitrites that are inhaled.
These substances are found in common household products like glues, lighter fluid, cleaning fluids, and paint products.
The chronic use of inhalants has been associated with a number of serious health problem:
Sniffing glue and paint thinner causes kidney abnormalities, while sniffing the solvents toluene and trichloroethylene cause liver damage.
Memory impairment, attention deficits, and diminished intelligence
Deaths resulting from heart failure, asphyxiation, or aspiration have occurred.
Slide18Slide197.Anabolic steroids
A type of
steroid that mimics the male sex hormone testosterone.
Medical uses of anabolic steroids include replacement of inadequate levels of testosterone resulting from a reduction or absence of functioning testes,& also for certain kinds of anemia and breast cancer.
Bodybuilders and athletes often use anabolic steroids to build muscles and improve athletic performance. But using them this way is not legal or safe.
Anabolic steroids have many psychological and physical side effects Including:
Liver
damage and cancer
Sterility, reduction of the size of the testes and breast enlargement in men.
Increased facial hair ,a deeper voice and decreased breast size in women.
Acne.
Permanently stunted growth in adolescents.
Aggressive behavior, mood swings, depression.
Hypertension.
High cholesterol.
Injuries to tendons and muscles.
Slide20Slide21General Management of drug abuse:
Stopping the use of the substance.
2.Pharmacotherapy
: as use of antidotes
e.g
:
Naloxone
for
opioid
abuse.
or substituting agents
e.g:a
long acting
opioid
(
e.g:methadone
) for shorter acting one(
e.g:heroin
) &use of chewed or
transdermal
nicotine.
3.Long term support, rehabilitation & Psychosocial therapies.