Illegal Drugs of Abuse

term 2

examples of opiates:

• morphine

• heroin

• fentanyl

common effects of opiates

• increase activity of dopaminergic neurons in mesolimbic pathway

• euphoria

• pain relief

• respiratory depression

• constipation

• pupil constriction

what is fentanyl and how potent compared to morphine?

• synthetic opiate

• 100x more potent

what happens with long term opiate use?

• dependence

• tolerance

• withdrawal symptoms if stopped

main active ingredient in cannabis:

Δ9-tetrahydrocannabinol (Δ9-THC)

short term effects of cannabis:

• mood elevation

• heightened senses

• relaxation

• increased appetite

• tachycardia, vasodilation, bronchodilation

• pain relief

• dry mouth

what is cannabinoid hyperemesis syndrome?

• rare condition from daily cannabis users

• cause repeated, severe vomiting and abdominal pain

• relieved by hot showers

examples of hallucinogens:

• LSD

• Psilocybin

what receptors does LSD act on:

• 5-HT2A serotonin receptor

• partial agonist

some effects of LSD:

• alters perception

• distorts senses

• ‘bad trips’: frightening images and paranoia

can LSD cause physical dependence?

no

• cause psychological dependence

• no withdrawal symptoms

examples of stimulants:

• cocaine

• amphetamines

• MDMA

How does amphetamine work in the brain?

• indirectly acts as sympathomimetic amine

• cause presynaptic release of NA and dopamine

What receptors does MDMA act on?

• partial affinity for serotonin transporters

• increases activity of serotonin and dopamine neurons

What does the Psychoactive Substances Act 2016 do?

Makes it an offense to produce, supply, import or export psychoactive substances for human consumption in the UK, with some exceptions.

What are some examples of NPS drugs?

• Mephedrone

• etizolam

• synthetic cannabinoids like Spice/K2

• dissociatives like methoxetamine

What is the chemical name for heroin?

Diacetylmorphine

How is heroin typically administered by street users?

• Injected under the skin, into a vein or muscle

• snorted

• smoked

• orally/rectally

What are some common adulterants found in street heroin?

• Glucose, starch

• powdered milk

• caffeine

• quinine

• flour

• chalk

What are some early withdrawal symptoms for opiates?

• Restlessness

• yawning

• runny nose

• sweating, chills

• diarrhea

• tremors

• low blood pressure

When do major opiate withdrawal symptoms peak?

Between 48-72 hours after the last dose

How long can insomnia, depression and drug cravings last during withdrawal?

persist for weeks or months

What type of anesthesia does ketamine produce?

Dissociative anesthesia

• amnesia, analgesia, hallucinations

What receptor does ketamine block?

• NMDAR receptor

  • at PCP site

• inhibits nAChRs and Na+ channels

What conditions is ketamine being explored to treat?

• Neuropathic pain

• chronic pain

• treatment-resistant depression

What are some withdrawal symptoms from cocaine?

• Intense depression

• irritability

• fatigue

• exhaustion

• cravings

What are some adverse effects of high dose MDMA?

• Severe anxiety

• hallucinations

• increased heart rate/blood pressure

• muscle cramps

• hyperthermia

• liver/kidney/cardiovascular failure

Mesolimbic release of dopamine can be produced by the following…

Morphine, heroin, cocaine, amphetamine, ecstasy, cannabis and also alcohol and nicotine

effects of binding to μ1 and μ2 opiate receptors:

μ1: mainly analgesia

μ2: mainly respiratory depression

effects of bindnig to kappa opiate receptors:

• spinal analgesia

• miosis

• sedation

effects of heroin after taking:

short term: rapidly enters brain, converts to morphine and binds to opiate receptors for a ‘high’

smoked or sniffed: peak effects less intense, felt in 10-15 mins

after initial CNS stim: higher brain centres depressed. decreased coughing, breathing reflexes, heart rate, dry mouth

uses of methadone:

• treats opiate addiction

• substitutes one addicition for another

• v difficult to detox from (up to 20 years)

what receptor does cannabis work on?

CB1 receptors

• in cerebral cortex and hippocampus

What are the two endogenous cannabinoids produced by the brain that are similar to Δ9-THC?

• Anandamide

• 2-arachidonylglycerol (2-AG)

both bind to synaptic cannabinoid receptors

What process are the endogenous cannabinoids believed to be involved in?

memory formation

side effects of smoking cannabis:

• bronchitis

• emphysema and lung cancer

• decreased fertility (dec sperm production, impaired ovulation)

medicinal uses of cannabis:

i.e nabilone and dronabinol

• chemotherapy-induced nausea and vomiting-resistant

• appetite stimulation from ED or AIDS

• treat acute and chronic pain

why is ketamine rarely used?

• serious abuse potential

when used:

• stimulates CVS for patients in shock

• chronic use can cause irreversible bladder damage

effects of taking amphetamines:

• euphoria

• increased alertness, confidence and concentration

• rapid talking

• increased stamina and physical energy

• decreased appetite

• tachycardia, sweating, increased BP and respiratory rate

withdrawal symptoms for amphetamines:

strong psychological dependence

• lethargy

• poor concentration

• hunger, excessive sleep

what is methamphetamine?

• highly addictive stimulant

• longer lasting and toxic effects on CNS

‘crystal meth’: crystalline smokable form

chronic use of MDMA can lead to…

damage to 5-HT neurons and impair memory function

withdrawal effects of MDMA:

• depression, anxiety, panic attacks

• sleeplessness

• paranoid delusions