Pharmacology Flashcards
Predicts the RATE of movement of molecules
Fick’s law of diffusion
Increase lipid solubility means increased absorption
True
Increased aqueous solubility means increased clearance
True
Pharmacokinetics is the?
Interaction of the body to the drug
Pharmacodynamics is the?
Interaction of the drug to the body
Relationshipd between ph and charge of molecule is predicted by?
Henderson-hasselbach equation
Which drugs are not given via IM due to the risk of causing hematomas?
Anticoagulants
Which route has partial bypass?
Rectal route cause the superior rectal vein absorptive n leads to bypass
Slowest route of drug administration
Topical route (local effect)
What route of administration undergoes first pass effect?
Oral route
Drug distribution is dependent on 4 factors which are?
Blood flow
Organ size
Protein binding
Solubility
Metabolic fate of the Drug?
A CITVATED
T ERMINATED
E LIMNATED
What Is the mode of elimination for drugs that are not metabolized?
Excretion
Rate of elimination is PROPORTIONATE to the CONCENTRATION
Rate of elimination decreases by 50% everytime
FIRST ORDER ELIMINNATION (most common)
Rate of elimination is CONSTANT regardless of concentration
Zero-order elimination
Concentration decreases linearly overtime
Zero-order elimination
What drugs display zero order kinetics?
WHAT PET (TOL BUTA ka naa sa sIDE o?)
Warfarin Heparin Aspirin Tolbutamide Phenytoin Ethanol Theophylline
Properties of a receptor
PMS
Most are PROTEINS
must be MODIFIED
must be SELCTIVE
_______ is the concentration required to bind 50% of the receptors
Kd
Smaller kd greater affinity
Concentration of a drug wherein half of the maximal effect is achieved
EC50
Maximal effect of a drug is defined by
EMAX
Maximal number of receptors bound are called
BMax
How do we compute for a THERAPEUTIC INDEX?
TI = TD50 / ED50
Higher TI the safer the drug
What is the therapeutic window?
It is the dose RANGE between the MEC and MTC
Drugs that display tachyphylaxis
MED Loves to watch CNN in HD
M etoclopramide
E phedrine
D obutamine
L SD
C alcitonin
N itroglycerin
N icotine
H ydralazine
D esmopressin
Most important pharmacokinetic parameter to be considered in defining a rational study state during dosage regimen
Clearance
Steady state is achieved in how many half lives?
4-5 half lives
Condition where administration is equal to elimination
Steady state
- amt of drug in the body does not change
What are phase I reActions?
HORDe
Hydrolysis
Oxidation
Reduction
Deamination
Drugs that are cytochrome P450 inducers
ETHel Booba takes PHEN-PHEN and Refuses Greasy Carb Shakes
Ethanol Barbiturates except secobarbital Phenytoin Phenobarbital Rifampicin Griseofulvin Carbamazepine Smoking and st.john's wort
Cytochrome p450 inhibitors
GRACE IS QVACK
Grapefruit juice Ritonavir Amiodarone Cimetidine Erythromycin
Isoniazid
Sulfonamides
Quinidine Valproic acid Allopurinol Chloramphenicol/chlorpromazine Ketoconazole
Suicide inhibitors
PASS
PTU
Allopurinol
Spironolactone
Secobarbital
Teratogenic effects
ACE INHIBITORS:\_\_\_\_\_\_\_\_\_\_\_ Antiepileptic drug:\_\_\_\_\_\_\_\_\_\_ Phenytoin:\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ OHA: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Barbiturates:\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
ACE INHIBITORS: fetal renal damage Antiepileptic drug: neural tube defects Phenytoin: FETAL HYDANTOIN SYNDROME OHA: neonatal hypoglycemia Barbiturates: neonatal dependence
DIETHYLSTILBESTROL (DES) if given in a pregnant patient can cause?
VAGINAL CLEAR CELL ADENOCARCINOMA
Teratogenic effects
Ethanol:\_\_\_\_ Lithium:\_\_\_\_ Isotretinoin:\_\_\_\_\_ Iodide:\_\_\_\_\_\_\_ Misoprostol:\_\_\_\_\_\_
Ethanol: fetal alcohol syndrome Lithium: ebstein's anomaly Isotretinoin: caraniofacial malformations Iodide: congenital hypothyroidism Misoprostol: mobius sequence
Teratogenic effects
Penicillamine:\_\_\_\_\_ Thalidomide:\_\_\_\_\_\_ Streptomycin:\_\_\_\_\_ Methimazole:\_\_\_\_\_\_ Sulfonamide:\_\_\_\_\_\_ Flourquinolones:\_\_\_\_\_\_\_ Smoking:\_\_\_\_ Tetracycline:\_\_\_\_\_\_
Teratogenic effects
Penicillamine:cutis laxo Thalidomide: phocomelia Streptomycin: ototoxicity Methimazole: aplasia cutis congenita Sulfonamide: kernicterus Flourquinolones: cartilage damage Smoking:IUGR Tetracycline: tooth discoloration
Induction of changes in the genetic material
Mutagenesis
Induction of developmental defects in the somatic tissues
Teratogenesis
An ANS drug used as a miotic during ocular surgery
Acetylcholine
ANS DRUG used in Bladder and Bowel atony?
BETANECHOL
SE: Diarrhea and urinary urgency
ANS drug that increases aqueous humor outflow and increased salivation
Pilocarpine
Drug used for glaucoma, sjogren syndrome and sicca syndrome
Pilocarpine
SE: miosis, bov and increased salivation
Triad of sjogren syndrome
Xerostomia, xerophthalmia and rheumatoid arthritis
Dry
Drug used for smoking cessation activating autonomic post ganglionic neurons
Nicotine
Drug used to test Myasthenia Gravis in TENSILON TEST. It differentiates cholinergic crisis and myasthenic crisis.
EDROPHONIUM
DOA: 5-15 minutes
A cholinomimetic that is used to TREAT Myasthenia Gravis
NEOSTIGMINE
ALT : Pyridostigmine
Cholinomimetic drugs for ALZHEIMER’S DISEASE
Rivastigmine - available as a transdermal patch
Galantamine
Donepezil — combined with MEMANTINE (NMDA receptor blocker) for ALZHEIMER’S dementia
Signs and symptoms of ORGANOPHOSPHATE POISONING
DUMBBELSS
diarrhea urination miosis Bronchospasm Bradycardia Excitation of skeletal muscles and CNS Lacrimation Salivation Sweating
What do you give in a patient with organophosphate poisoning?
Atropine - antidote DOC
Notable SE: hyperthermia
Drug for organophosphate poisoning that should be given 6-8 hours after exposure to be rendered effective
PRALIDOXIME - antidote for early stage
This binds to phosphorus of organophosphate regenerating active acetylcholinesterase
Prototype nonselective muscarinic blocker
Atropine
Anticholinergics used for PARKINSON’S disease that reduces tremors
Muscarinic antagonists
Try Benz BEEP BEEP
trihexyphenidyl
Benztropine
BIPERIDEN
Ipratropium MOA
Its a muscarinic receptor antagonist that blocks receptors in bronchial smooth muscles preventing bronchoconstriction
USES: Acute asthma and COPD
Bronchodilator of choice for patients with COPD AND HEART DISEASE
Ipratropium bromide (less likely to cause arrhythmias and tachycardia)
Transdermal patch used for motion sickness
SCOPOLAMINE
SE: drowsiness, BOV, dry eyes, dry mouth, urinary retention and constipation
A muscarinic antagonist used in IBS
Dicyclomine / dicycloverine
A cholinergic antagonist used for urge incontinence by reducing detrusor muscle tone
Oxybutynin patch
Signs and symptoms of atropine toxicity
Hot as a hare (hyperthermia) Dry as a bone (decreased secretion) Red as a beet (cutaneous vasodilation) Blind as a bat (blurred vision) Mad as a hatter (CNS toxicity)
Contraindications to muscarinic blockers
ABCs of muscarinic receptor use
Acute angle closure glaucoma
Benign prostatic hyperplasia
Cautious use in infants
Only depolarizing neuromuscular blocker
Succinylcholine
DOC for anaphylaxis
Epinephrine
If epinephrine is given n a pregnant patient, the OB should watch out for?
Fetal anoxia
Given in neurogenic shock and the last resort for caridiogenic shock
Norepinephrine
Epinephrine can cause hyperglycemia or hypoglycemia?
Hyperglycemia
Toxic effects of norepinephrine
RATEE!
Reflex bradycardia Arrhythmias Tissue necrosis Excessive increase in BP Extreme vasospasm
Dose dependent action of dopamine
Low dose (1-5 mcg/kg/min) - D1 receptors increasing renal blood flow and urine output
Medium dose (5-15 mcg/kg/min) - B1 receptors increasing heart rate and contractility
High dose (>15 mcg/kg/min) - A receptors causing vasoconstriction thus increasing blood pressure
This is a synthetic catecholamine that is a beta nonselective sympathomimetic used in ASTHMA
Isoproterenol
An Alpha 1 selective sympathomimetic used for nasal decongestion
Phenylephrine
Notable SE: piloerction
Patient took 100 tablets of a sympathomimetic nasal decongestant. What can be given as antidote?
Phentolamine is the DOC for alpha 1 agonist overdose
Patient had rebound hypertension after abrupt withdrawal of clonidine. What can be given?
Phentolamine
An alpha 2 selective agonist given in opoid withdrawal?
Clonidine
*also given in cancer pain and hpn
Methyldopa is an alpha 2 agonist that is given in gestational hypertension and preeclampsia. What is a notable side effect of this drug?
Sedation and HEMOLYTIC ANEMIA (positive coomb’s test)
Alpa 2 agonist that decreases SECRETION of aqueous humor used in GLAUCOMA
Apraclonidine (C)
Brimonide (B)
SE: hyperemia, eye discomfort, pruritus,BOV and dry mouth
Beta 1 agonist used in cardiac stress testing
DOBUTAMINE
Drug of choice for acute asthma attack
Beta 2 selective agonist causing bronchodilation
Albuterol/ Salbutamol
Uses of ISOXUPRINE
Tocolysis for preterm labor
Vasodilator in Raynaud’s phenomenon
Beta 2 agonist drugs
S albutamol T erbutaline A lbuterol I soxuprine R itodrine
*TIR used for tocolysis
A sympathomimetic drug that causes appetite suppression and nasal vasoconstriction
Phenylpropanolamine
Tox: HEMORRHAGIC STROKE
An alpha nonselective antagonist used in the treatment of PHEOCROMOCYTOMA by IRREVERSIBLE blockage of alpha adrenergic receptors
PHENOXYBENZAMINE
An alpha nonselective antagonist used in the treatment of PHEOCROMOCYTOMA by REVERSIBLE blockage of alpha adrenergic receptors
Phentolamine, tolazoline
Uses of PHENTOLAMINE
Rebound hypertension
Antidote for alpha 1 agonist overdose
pheochromocytoma (presurgical)
Used for benign prostatic hyperplasia
Tamsulosin which is an alpha 1 selective antagonist that is most selective for prostatic smooth muscles
Other drugs: pazosin, terazosin “osin”