basic pharmacology block 2 review. what are adrenergic agonist drugs that mimic the effects of...
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Basic Pharmacology
Block 2 Review
What are adrenergic agonist
• Drugs that mimic the effects of adrenergic nerve stimulation (or stimulation of the adrenal medulla)
• Mimic the effects of norepinephrine or epinephrine• These drugs are known as adrenomimetics or
sympathomimetics• Remember the actions of the SNS are mediated
through alpha and beta receptors.
Remember
• Alpha 1: most vascular smooth muscle, agonist contract
• Beta 1: heart, agonist increase rate• Beta 2: respiratory and uterine smooth
muscle, agonists relax.
Name alpha selective direct – acting agonists
• Phenylephrine• Methoxamine• Clonidine• methyldopa
Identify the major beta selective direct-acting agonist
• Dobutamine• Isoproterenol• Albuterol• Metaproterenol• Terbutaline
List the major alpha and beta direct-acting agonists
• Epinephrine• Norepinephrine• dopamine
Direct- acting agonists considered catecholamines
• Epinephrine• Norepinephrine• Isoproterenol• Dopamine• dobutamine
Uses of this drugs
• Nasal decongestant• ADHD• CVS• Ventricular Arthymias• Brochospasm• Shock
Organization of Class
• The effect of the SNS can be blocked either by decreasing sympathetic outflow from the brain, suppressing release of NE from terminals or by blocking postsynaptic receptors.
• Adrenergic antagonists reduce the effectiveness of sympathetic nerve stimulation and effects of exogenously applied agonists, such as isoproterenol.
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ADRENERGIC BLOCKERSALPHA BLOCKERS
Alpha 1 Blockers Nonselective Alpha Blockers• Doxazosin Phenoxybenzamine • Prazosin Phentolamine• Terazosin• Most alpha antagonists allow vasodilatation and thus, decrease
blood pressure( remember a-receptor activation results in vasoconstriction)
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BETA BLOCKERSNon Selective Beta 1 selective
Blockers Blockers• Propranolol Metoprolol • Timolol Atenolol• Nadolol Esmolol Acebutolol• Betaxolol • Labetalol - Both Alpha and Beta Blocker• Beta 1receptors found in the heart and their activation leads to an
increase in HR and contractility .• Beta 2 receptor are found in SM of the respiratory tract, the uterus
and blood vessels. Their activation leads to relaxation of SM
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DRUGS AFFECTING NEUROTRANSMITTER UPTAKE OR RELEASE
• Cocaine• Guanethidine• Reserpine
Main use
• HTN• Benigh Prostate Hypertrophy• Angina• Glaucoma• Post MI
CNS 1
• Drugs used to treat parkinsonism• Dopamine replacement therapy: levodopa and
carbidopa• Dopamine Agonist Therapy: Bromocriptine.Pergolide, pramipexole, ropinirole and rotigotine• Anticholinergic therapy:• Trihexyphenidyl• Benztropine• Biperiden
CNS 2ANXIOLYTICS, HYPNOTICS AND
SEDATIVES• Benzodiazepines- the most frequently
used drugs for anxiety• Azaspirones- for example, buspirone• Carbamates- for example, meprobamate• Barbiturates- rarely used today because of
severe side effects and a low therapeutic index. These drugs have generally been replaced by the benzodiazepines.
WHAT ARE THE THERAPEUTIC INDICATIONS FOR BENZODIAZEPINES
• These drugs are used clinically as muscle relaxants and in the treatment of the following:
• Anxiety disorders• Panic disorders- alprazolam is the drug of choice• Status epilepticus- diazepam is the drug of choice• Sleep disorders• Insomnia- all benzodiazepines can be sedating but
lorazepam and temazepam are the most commonly used.
• Alcohol withdrawal- Chlordiazepoxide most commonly used.
WHAT ARE THE THERAPEUTIC INDICATIONS FOR BARBITURATE ADMINISTRATION
• Induction of anesthesia- thiopental• Anticonvulsants- e.g, phenobarbital• Treatment of anxiety• Induction of hypnosis• Why are benzodiazepines favored
over barbiturates for the treatment of anxiety?
• Benzodiazepines have a much higher therapeutic index than do barbiturates
CNS 3: CNS STIMULANTS
• 1. methyxanthines• 2. amphetamine• 3. nicotine• Main use: appetite control, ADHD, Narcolepsy,
excitement and euphoric properties, decrease fatigue,
CNS 4: Antipsychotic Drug
• Antipsychotic, also known as neuroleptics are drugs used primarily to treat psychotic states such as schizophrenia, delusional disorder and other hallucinatory states
TRADITIONAL ANTIPSYCHOTICS
• PHENOTHIAZINES• EXAMPLES• CHLORPROMAZINE (THORAZINE)• FLUPHENAZINE (PROLIXIN)• THIORIDAZINE(MELLARIL)• PERPHENAZINE ( TRILAFON)• What distinctive side effects does thioridazine cause?• Pigmentary retinopathy• May cause cardiac arrhythmias and conduction block
BUTYROPHENONES• Name two drugs in this class• Haloperidol ( haldol)• Droperidol( inapsine)• Haloperidol can also be used
for • tourette’s syndrome • Huntington’s disease• Phencyclidine overdose- drug
of choice• Side effects are Extrapyramidal
side effects
• DIBENZOXAZEPINES• Name a drug that belongs
to this class• Loxapine ( loxitane)
• THIOXANTHENES• Name a drug that belongs
to this class?• Thiothixene ( navane)
CLINICAL USES AND SIDE EFFECTS
• What are the clinical applications of traditional antipsychotic agents?
• Treatment of agitated or psychotic state such as bipolar disease or schizophrenia. They are effective for positive symptoms of schizophrenia such as delusions, thought disorders and hallucinations.
• Antiemetic therapy ( dopamine blockade except thioridazine )
• Tourette’s syndrome: haloperidol• Intractable hiccups_ chlorpromazine• Antipruritic therapy_ promethazine ( histamine blockade)
Atypical antipsychotic drugs( SEROTONIN-DOPAMINE ANTAGONISTS)
• Examples • Clozapine ( clozaril)• Risperidone ( risperdal)• Olanzapine ( zyprexa)• This drugs are called atypical because in
addition to blocking dopamine receptors they also produce significant blockade on serotonin
( 5-HT) receptors
CNS 5:ANESTHETICS
• * GENERAL• * LOCAL• General anesthetics are given either as inhaled
or intravenous agents. • They primarily have CNS effects• Local agents are injected at the operative site
to block nerve conduction
INHALED AGENTS
• HALOTHANE• ENFLURANE• ISOFLURANE• SEVOFLURANE• NITROUS OXIDE• There potency is defined base on the concept
of minimum alveolar concentration ( MAC)
IV
• Thiopental• Ketamin• Propofol• Etomidate• fentanyl• Know their uses and side effect
ANESTHETICS
NAME THE ESTER ANESTHETICS NAME THE AMIDE ANESTHETICS
• COCAINE• BENZOCAINE• PROCAINE • TETRACAINE
• LIDOCAINE• MEPIVACAINE• BUPIVACAINE• PRILOCAINE