basic pharmacology block 2 review. what are adrenergic agonist drugs that mimic the effects of...

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