Pharmacology Exam 1
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- What are the cardiovascular effects of ephinephrine?
- Increases heartrate & force of contraction
- What happens to blood vessels with epinephrine?
- Contricts arterioles in skin, mucous membranes and viscera.
- These drugs are AKA sympathomimetics, adrenergic agonists or adrenoceptor agonists.
- Adrenergic drugs
- These drugs mimic the effect of stimulation of sympathetic nervous system.
- Adrenergid drugs
- Adrenergic drugs can be divided into what two groups?
- Direct and indirect acting
- This type of adrenergic drug includes NE, epinephrine and closely related adrenergic agonists.
- Direct acting
- Postganglionic sympathetic fibers are also known as __________?
- Adrenergic neurons
- Adrenergic receptors are classified into these two major groups
- Alpha α, and Beta β
- NE release from the synaptic vesicles diffuses across the synaptic cleft and binds to __________ or ___________.
- postsynaptic receptors or target cells
- This adrenergic receptor is located in the bronchial smooth muscle and its effect is bronchodialation
- Beta two (β 2)
- This adrenergic receptor is located in the heart and its effect is to increase its rate and force of contraction.
- Beta one (β 1)
- This adrenergic receptor is located in the vascular smooth muscle and its effect is vasoconstriction
- Alpha one (α 1)
- This adrenergic receptor is located in adrenergic and cholinergic nerve terminals and its effect is to decrease neurotransmitter release
- Alpha two (α 2)
- This is the study of the interaction of chemicals with biological systems.
- Pharmacology
- The study of the biochemical and physiological effects of drugs and their mechanism of action
- Pharmacodynamics
- Thy study of the absorption, distribution, metabolism and excretion of drugs.
- Pharmacokinetics
- The study of the adverse effects of drugs
- Toxicology
- The use of drugs in the prevention, diagnosis and treatment of disease
- Therapeutics
- Drugs can be identified by these three names
-
Chemical
Generic (nonproprietary, official)
Trade (proprietary) - N-acetyl-p-aminophenol is an example of which type of drug name?
- Chemical name
- Tylenol, Anacin are examples of what kind of drug name?
- Trade or proprietary
- This type of drug administration involves passage of drugs into the alimentary tract
- Enteral
- This route of drug administration bypasses the alimentary tract
- parenteral
- This route of drug administration is the most commonly used and included oral, rectal, buccal and sublingual.
- Enteral
- This route of drug administration has the advantage of being the safest route and is cheap. Its disadvantages are the variation in rate of absorption and problems with patient compliance.
- Enteral
- This route of drug administration has the advantage that it can be used in an emergency and with an unconscious pt. The disadvantages are increased risk of adverse effects, sterile formulations required, expense and expertise required.
- Parenteral
- This route of drug administration is the application of drugs to various mucous membranes and skin.
- Topical
- This route of drug administration is the application of gaseous and volatile drugs for absorption from the respiratory tract.
- Inhalation
- The rate at which a drug leaves the site of administration and the extent to which this occurs.
- Drug Absorption
- Name the factors effecting the absorption of drugs.
-
Drug solubility
Blood flow
Route of administration - Name the factors that modify the distribution of drugs
-
Tissue permeability
Extent of protein binding - This is a major mechanism by which drug action is terminated. It involves chemical alteration of drugs in the body.
- Metabolism or Biotransformation
- This is the major site of metabolism of many drugs and xenobiotics.
- Liver
- What is the most important organ for elimination of drugs.
-
Kidneys
Also include, lungs, biliary system and intestines. - Drugs act mainly on Receptors which are generally proteins or glycoproteins that are present: (name 3 areas)
-
* On the cell surface
* On an organelle within the cell
* In the cytoplasm - This is a combination of a drug with a receptor which results in a molecular change in the receptor which can trigger a chain of events leading to a response.
-
Drug-Receptor Interactions
Drug + Receptor --> Drug Receptor complex --> Response - This is a low concentration of drug required at a receptor.
- Sensitivity
- This is a drug that activates a receptor in order to elicit a response.
- Agonist
- This is a drug which does not evoke a maximal response as compared to the strong agonist.
- Partial agonist
- The degree of effect produced by a drug is generally a function of the amount of drug administered.
- Dose-response curve
- As the dosage administered to a single subject or isolated tissure is increased, the pharmacologic effect will also increase until at certain dose, the effect reaches a maximum. What is this called?
- Graded responses
- A plot of the response vs. the logarithm of the dose will yield a sigmoid curve. What is this called?
- The log.dose-response curve
- This is the effective dose (or concentration which causes 50% of the maximum response.
- EC 50
- This is an all-or none response to a drug and relates to the frequency with which a specified dose of a drug produces a specific response in a population.
- Quantal Response
- The minimum dose that is effective for 50% of the population
- ED 50
- The minimum dose causing lethal effect in 50% of the population
- LD 50
- A ratio used to evaluate the safety and usefulness of a drug for an indication.
- Therapeutic Index
- The margin between therapeutic and lethal doses of a drug.
- Margin of Safety
- These are receptors for acetylcholine
- Cholinergic Receptors
- A chemical that is released at the nerve ending
- Neurotransmitter
- These neurons are located at the lumbar and thoracic portions of the spinal cord in the Sympathetic System.
- Preganglionic neurons
- Where are the ganglia located in the Sympathetic nervous system?
- usually close to the spinal cord so that preganglionic axons are short and the postganglionic axons are long.
- This is the neurotransmitter which is released from most postganglionic sympathetic nerves.
- Norepinephrine
- What is the neurotransmitter which is released from preganglionic fibers in the sympathetic nervous system?
- ACh
- What is the neurotransmitter which is released from postganglionic sympathetic nerves supplying the sweat glands and piloerector muscle in the Sympathetic Nervous System?
- ACh
- These drugs mimic the effect caused by sympathetic nerve stimulation, release NE from neuronal storage sites and its effects can be inhibited by neuronal uptake blockers such as cocaine and despramine.
- Indirect-Acting Adrenergic Agonists
-
These drugs are AKA
Sympatholytic
Adrenergic blocking drugs - Adrenergic antagonists
- These drugs bind to adrenergic receptors but do not trigger a response
- Adrenergic Antagonists
- These drugs prevent activation of receptors by endogenous catecholamines
- Adrenergic antagonist
- These drugs can bind to both α and β receptors
- Adrenergic Antagonists
-
Phenoxybenzamine (prototype)
Phentolamine
Prazosin
Yohimbine
These are examples of what types of drugs? - α - Adrenergic antagonists
- This drug decreses total peripheral resistance, induces postural hypotension, can cause reflex tachycardia and an increase in cardial output and can impair ejaculation of semen.
- Phenoxybenzamine (prototype)
- This drug is used in Hypertensive crises, peripheral vascular disease (e.g. Raynaud's phenomenon), and Paraplegics to contol autonomic hyperreflexia.
- Phenoxybenzamine
- These drugs include nonselective blockers and selective β 1 receptor antagonists.
- β - Adrenergic Antagonists
- This drugs side effects include bronchoconstriction: can be potentially lethal in asthmatics, cardiac arrythmias: may occur if there is rapid withdrawal from drug, and sexual impairment: mechanism unknown.
- Propranolol (prototype)
-
The therapeutic uses of this drug include:
Hypertension, Prophylaxis of angina sections, arrthythmias and myocardial infection, prophylaxis of migrane headaches and glaucoma - Propranolol (prototype)
- What are the two subdivisions of the Peripheral nervous system?
- Autonomic and Somatic
- This division of the PNS controls skeletal muscles function and is voluntary.
- Somatic
- This division of the PNS controls involuntary processes such as, contraction and relaxation of smooth muscles, all exocrine and endocrine secretions, cardiac muscle function, certain metabolic functions.
- Autonomic
- What are the two anatomical divisions of the Autonomic system?
- Sympathetic and Parasympathetic
- This division of the PNS consist of two neurons arranged in series (two-neuron pattern).
- Autonomic
- Which nerves are associated with the parasympathetic system?
- Cranial and Sacral nerves
- Which nerves are associated with the sympathetic system?
- Thoracic & Lumbar nerves
- In which system are ganglia usually close to the innervated organ?
- Parasympathetic
-
FACT
Parasympathetic system
* When Ach is released from nerve terminals, it diffuses across the synaptic cleft to bind to postsynaptic receptors on target cells
* Receptors for ACh (Cholinergic receptors or cholinoceptors) are broadly subd - .
- These receptors bind to ACh and ______ with a higher affinity than nicotine.
- Muscarinic
- These receptors bins to ACh and ______ with a higher affinity that muscarine.
- Nicotinic
- These receptors are present in ganglionic synapses (both sympathetic and parasympathetic), neuromuscular function and the brain.
- Nicotinic
- These drugs are AKA parasympathomimetic
- Cholinergic drugs
-
Drugs in this group include:
ACh, syntetic ester of choline, naturally occurring alkaloids such as pilcarpine. - Direct-Acting Cholinergic drugs
- These drugs bind directly with ACh receptors.
- Direct acting Cholinergic drugs
-
The parmacological actions of this drug include:
inhibits HR, increase in gastrointestinal motility, contraction of smooth muscle of the bronchioles, urinary bladder, uterus, circular muscle of the iris, cillary muscle of eye. It also stimulates sal - Direct acting Cholinergic drugs
- These drugs facilitate the parasympathetic system.
- Direct acting Cholinergic drugs
- Side effects of these drugs include: myopia and miosis, bronchoconstriction, nausea, vomiting, diarrhea, excessive urination and uterine pain.
- Direct acting Cholinergic drugs
-
Therapeutic uses of this drug include:
Miotic in cataract surgery and treatment of glaucoma (causes contraction of the eye). - Direct acting Cholinergic drugs
- These drugs do not directly bind on the receptor. They act on ganglia in both parasympathetic and sympathetic.
- Indirect acting Cholinergic Drugs
- These drugs effect Autonomic ganglia: facilitation of cholinergic transmission leading to an increase in both sympathetic and parasympathetic actions.
- Indirect acting Cholinergic Drugs
- These drugs enhance neuromuscular transmission in low doses.
- Indirect acting Cholinergic Drugs
- Neostigmine is an example of this drug. It is used to reverse the muscle paralysis caused by tubocurarine and related drugs and in the treatment of myasthenis gravis.
- Indirect acting Cholinergic Drugs
- Physostigmine is an exp. of these drugs and is used in the tx of poisoning with atopine and other antimuscarinic drugs
- Indirect acting Cholinergic Drugs
- Edrophonium is and exp of these drugs and is used in differential diagnosis of myasthenia gravis.
- Indirect acting Cholinergic Drugs
- Demecarium and Ecothinphate are exp of these drugs and are used in the tx of glaucoma.
- Indirect acting Cholinergic Drugs
- These drugs are AKA muscarinic receptor antagonists. They include atropine, scopolamine, methscopolamine and propantheline.
- Anticholinergic Drugs
- The side effects of these drugs include: Tachycardia (^ HR), mydriasis leading to photophobia, dry mouth, constipation, drowsiness, hallucinations, urinary retention.
- Anticholinergic Drugs
- Drugs that modify skeletal muscle function fall into these two major groups.
- Neuromuscular blockers and Spasmolytics
- This means rigidity of spasm
- Spasticity
- Arrival of impuse at motor nerve terminal leads to the release of ____.
- ACh
- ACh diffuses across the ___________ to activate nicotinic receptors located on motor end plate.
- synaptic cleft
- An increase in ionic permeability leads to changes in membrane potential and the gereration of an end plate potential. This is also called what?
- Depolarization
-
FACT:
The magnitude of the end plate potential is proportional to the amount of released ACh - .
-
FACT
Dose-response curve
The effects caused by two drugs acting on the same receptor can be compared (dose-response curves will be parallel to each other) - .
-
FACT
Epinephrine
* A large iv dose of epinephrine will cause an increase in blood pressure, while a low dose will cause a fall in blood pressure - .
-
FACT
Epinephrine effects on smooth muscle
* Relaxation of bronchial smooth muscle
* Relaxation gastrointestinal smooth muscle and contraction of sphincter
* Relaxation of detrusor muscle and contraction of sphincter - .
-
FACT
Metabolic effects of epinephrine
* Carbohydrate- increased glyco-genolysis leading to hyperglyemia
* Fat - lipolysis leading to an increase in free fatty acids - .
-
FACT
Quantal Response
The construction of a quantal dose-response curve requires that data be obtained from many individuals. The smallest dose that will produce a quantal response is not the same for all members of a population. - .
-
FACT
Side effects of epinephrine
CNS: Anxiety, headaches
CVS: Cerebral hemorrhages and cardiac arrhythmias
RESPIRATORY: pulmonary edemas from pulmonary hypertension - .
-
FACT
Therapeutic used of Anticholinergic Drugs
* Anesthesiology: pre-anesthetic medication to reduce secretions
* Ophthalmology: mydriasis for eye examinations
* Antidote for poisoning with AChE inhibitory
* Scopolamine is employ - .
-
FACT
Metabolism
* Metabolism can (but not always) result in inactivation of the drug
* Some drugs are activated by metabolism (prodrugs) - long activity - .
- In what system is ACh the neurotransmitter released from all pre and post ganglionic fibers?
- Parasympathetic
-
FACT
Binding of Drugs to Plasma proteins
* Many drugs are bound to plasma proteins, usually albumin
* Drugs bound to plasma proteins are pharmacologically inactive
* Binding occurs in a reversible fashion and is in dynamic equilibrium - .
-
FACT
Physiology of Neuromuscular Tranmission
* Arrival of impulse
* Opening of Ca 2+ channels
* Release of ACh by exocytocis
* Binding of ACh to nicotinic receptors
* Muscle contraction - .
- These drugs work by blocking transmission at the neuromuscular junction.
- Neuromuscular Blocking drugs
- Blockade of normal end plate function can occur by two mechanisms and these are the two classes of drugs...
- nondepolarizing (competitive blocker)and Depolarizing drugs
-
The following are exp of what type of drug:
Tubocuraruine, Gallamine, Vacuronlium, atracurium - Nondepolarizing blocker
-
The following are exp. of what type of drugs?
Succinylcholine, Decamethonium - Depolarizing drugs
- This type of drug acts by combining with nicotinic receptors on motor end plate there by preventing the binding of ACh
- Tubocuratine and other nondepolarizing heuromuscular blocking drugs
- This drug prevents depolarization of muscle cell membrane and inhibit muscle contraction
- Tubocurarine
- The effect of these can be overcome by increasing the concentration of ACh in the synaptic gap (e.g. using AChE inhibitors)
- nondepolarizing agents
- This drug is administered by the parenteral route (i.v.), penetrates membranes poorly, has an onset time of 4-6 hrs and a duration of 80-120 min., is not metabolized and is excreted in urine unchanged.
- Tubocurarine
- This drugs side effects may cause bronchospasm because of histamine release (asthma-like reaction)
- Tubocurarine
- When plasma cholinesterase, the enzyme that metabolizes succinylcholine is absent at the end plate; termination of event is by diffusion away from the end plate. What is the consequence?
- Flaccid paralysis of muscle occurs
- This drugs side effects include potural hypotension, impotence in men, nasal stuffiness and nausea and vomiting.
- Phenoxybenzamine (prototype)
- These drugs have a rapid onset of action (1-1.5 min) and the duration is 6-8 min.. They are rapidly hydrolyzed by plasma cholinesterase
- Succinylcholine
- These types of drugs bind to receptor and can come off.
- Non depolarizing
- This is a drug which is devoid of the activity of an agonist. Examples include atropine and tubocurarine.
- Antagonist
- The side effects of these drugs include: Fasciculations can cause muscle pain, Contraction of extra-ocular muscles can lead to increase in intraocular pressure
- Succinylcholine
-
The therapeutic uses of these drugs are:
Used as surgical adjuvants to anesthesia.
For promoting skeletal muscle relaxation
For facilitating endotracheal intubation - Tubocurarine and succinylcholine
- This condition is characterized by an increase in tonic stretch reflexes (exaggerated muscle stretch reflex). It is often associated with cerebral palsy, MS, stroke and traumatic lesions to the brain and spinal cord (including quadriplegia and paraplegia
- Spasticity
- This condition is usually due to a lesion in spinal cord or brain or due to loss on control of supraspinal inhibition.
- Spasticity
- This term is used to describe the increased tension often associated with certain musculoskeletal injuries and inflammation (e.g. muscle strain/tightness). It involves afferent nocieptive nput from damaged tissue which excites outflow of α motor neuron
- Muscle spasms
-
This type of drug are divided into the following 2 groups:
* Direct-acting drugs such as dantrolene sodium
* Central-acting drugs such as baclofen,k diazapam and chlorzoxazone - Spasmolytic Drugs
- This type of drug reduces skeletal muscle strength by interfering with excitation-contraction coupling in the muscle fiber
- Dantrolene Sodium (Dantrim, prototype)
- This type of drug impairs the release of calcium from the sarcoplasmic reticulum
- Dantrolene Sodium (Dantrim, prototype)
- This type of drug does not affect neuromuscular transmission nor does it change the electrical properties of skeletal muscle.
- Dantrolene Sodium (Dantrim, prototype)
- This drug interfere with release of Ca 2+ from sarcoplasmic reticulum in skeletal muscle.
- Dantrolene Sodium (Dantrim, prototype)
-
The following is the transmission of what drug?
* Depolarization
* Opening of channels to release Ca 2+ from sarcoplasmic reticulum
* Release of Ca 2+ promotes interaction of actin and myosin (muscle contraction) - Dantrolene Sodium (Dantrim, prototype)
-
This drug has the following Pharmacokinetics:
* Active orally
* Absorption from the g.i.t. is slow (only 30% of oral dose is absorbed
* half-life is about 8 hrs.
* Undergoes liver metabolism and excretion in the urine - Dantrolene Sodium (Dantrim, prototype)
-
The side effects of this drug include:
* Generalized muscle weakness
* Liver toxicity
* Euphoria drowsiness and diarrhea - Dantrolene Sodium (Dantrim, prototype)
-
The therapeutic uses of this drug include:
* Relief of spasticity regardless of underlying pathology
* Management of malignant hyperthermia syndrome precipitated by administration of neuromuscular blocker and inhalational anesthectics during su - Dantrolene Sodium (Dantrim, prototype)
- This drug directly acts to inhibit release of ACh from presynaptic vesicles, used to control severe spasticity
- Botulinium (BOTOX)
- This drug is a derivative of central inhibitory neurotransmitter, GABA (agonists)
- Baclofen, (LIORESAL, prototype)
- This is a direct acting catecholamine synthesized in the adrenal medulla. It interacts strongly with α and β receptors.
- Epinephrine
- This is when a receptor can only be activated with drugs with similar chemical structure.
- Selectivity
- This route of drug administration includes Intravenous, intramuscular, subcutaneous, intraperitoneal, intra-arterial and intrathecal.
- Parenteral
- This route of drug administration is lipid soluble and is the application of drugs directly to the surface of the skin for absorption through the dermal layers.
- Transdermal
- This type of drug will bind and stay there, causing continuous contraction, flaccid paralysis
- Depolarizing
- Two types of drug administration
- Enteral and Parenteral
-
This drugs pharmacological actions include:
* Reduces the frequency and severity of flexor or extensor spasms
* Reduces increase flexor tone
* Effective in pts with complete spinal transections suggesting that its primary site of action i - Baclofen, (LIORESAL, prototype)
-
This drugs Pharmocodinetics include:
* Active orally. Plasma half-life is about 3-4 hours
* largely excreted unchanged by the kidney - Baclofen, (LIORESAL, prototype)
-
The side effects of this drug include:
* CNS: drowsiness, insomnia, dizziness and headache
* Muscle weakness
* G.I.T. - nausea - Baclofen, (LIORESAL, prototype)
-
The therapeutic uses of this drug include:
* Spasticity associated with lesions of the spinal cord including traumatic injuries resulting in paraplegia and quadriplegia
* Spasticity associated with disease of the spinal cord e.g. demyelination - Baclofen, (LIORESAL, prototype)
- This drug increase inhibitory GABA effect, is centrally acting. AKA as valium
- Diazepam
- This drug enhances the GABA effect
- Gabapentin (NEURONTIN)
- This drug is an α2 agonist
- Tizanidine
-
FACT
Drugs Affecting Skeletal Muscle
Neuromuscular Blockers
* Depolarizing
* Nondepolarizing
Spasmolytics
* Direct
* Centrally acting - .
- Acetaminophen and Aspirin are examples of what drug name?
- Generic, nonproprietary or official
- Drugs being eliminated from the body either unchanged or as metabolites is this process.
- Drug excretion
-
FACT
Depolarizing agents: Summary of mechanism of action
* Binding of succlaylcholine to nicotinic receptors
* Depolarization
* Spreading of depolarization to adjacent membranes
* Generalized contraction of muscle motor units (tr - .
-
FACT
Drugs may also interact with
* Enzymes (physostigmine/acetylcholinesterase) - transport systems (ouabain/ Na+-K+-ATPase)
* by non-specific physicochemical mechanisms (antacids, osmotic diuretic, and anesthetic gases) - .
- List the 5 steps of the neurotransmitter release process.
-
1. Arrival of Impulse
2. Opening of Ca 2+ channels
3. Release of NE by exocytocis
4. Binding of NE to adrenergic (α or β)
5. Effect - Name the 3 processes of renal excretion of drugs
-
* Glomerular filtration (water soluble and polar compounds)
* Active tubular secretion (organic acids like penicillin)
* Passive tubular reabsorption - The delivery of drug from the systemic circulation to tissues.
- Drug distribution
- The pharmacological actions of these drugs: case an initial muscle tremor and fasiculations followed by a period of flaccid paralysis.
- succinylcholine
-
The pharmacological effects of these drugs include,
* mimic the effects of stimulation of the parasympathetic system
* act on receptors that are activated by ACh in smooth muscle, cardiac muscle, and some glands. - Cholinergic drugs
- These are agents used to reduce spasticity in a variety of neurological conditions.
- Spasmolytics
- These are agents used to cause muscle paralysis during surgical procedures.
- Neuromuscular blockers
- These drugs act on receptors that are activated by NE in smooth muscle, cardiac muscle and some glands.
- Adrenergic drugs
- These drugs pharmacological actions include: ^ HR, v in gastrointestinal motility, relaxation of smooth muscles of the bronchioles, urinary bladder, circular muscle of the iris and ciliary muscle and mydriasis, v in secretions from salivary sweat and lac
- Anticholinergic Drugs
- When a drug binds to a receptor, one of these two things can occur.
-
* an ion channel is opened or closed
* biochemical messengers (or second messengers) are activated. -
These organs and tissues receive innervations only from this system.
Adrenal medulla, pilorector muscle, spleen, vasculature, sweat glands and kidney. - Sympathetic Nervous System
- This drug acts of GABA β receptors and they reduce the release of excitatory transmitters from the brain and spinal cord leading to presynaptic inhibition
- Baclofen, (LIORESAL, prototype)
- This drug is a depolarizing agent. It binds to the nicotinic receptor (like ACh), and unlike ACh, it causes a persistent depolarization of the motor end plate leading to a block in the conduction of impulses. With prolonged exposure to this drug there is
- Succinylcholine
-
This drug has the following pharmacological actions:
Decreases HR and cardiac output, decreases total coronary BF and O2 consumption,there is a gradual decrease in both systolic and diastolic FP in hypertensive pts., increase in airway resistance by - Propranolol (prototype)