General Flashcards
What is the half life equation?
T1/2=0.7Vd/CL and t1/2=0.7/Ke
What is the loading dose equation? What is the maintenance dose equation?
Loading dose=Cp*Vd/F Maintenance dose=Cp*CL*tau/F
Which drugs have 0-order elimination?
Phenytoin, ethanol, aspirin - Cp decreases per time
What are examples of weak acid drugs and what is the antidote?
Examples: phenobarbital, MTX, aspirin, TCAs Antidote: bicarbonate
What is an example of a weak base drug and what is the antidote?
Amphetamines and the antidote is ammonium chloride
Drug efficacy is measured by what?
Vmax
How is volume of distribution calculated?
Vd=F*(dose of drug given)/plasma drug concentration
How is potency measured?
Lower EC50 correlates with higher potency - less drug needed for same effect
How do competitive antagonists change potency and efficacy?
Decreases potency and no change in efficacy
How does a noncompetitive antagonist affect potency and efficacy?
Decreases efficacy and cannot be overcome by adding substrate
What is the therapeutic index?
Therapeutic index= TD50/ED50= median toxic dose/ median effective dose
What kind of receptors are nicotinic and muscarinic receptors and where are they located?
Nicotinic receptors - Ligand ACh gated Na/K channel found at all post synapses from initial neuron. Muscarinic receptors - ACh Gcoupled receptors located in parasympathetic post ganglionic cardiac, smooth muscle, gland cells and nerve terminals and sympathetic post ganglionic sweat glands
alpha1 receptors: what is the Gprotein class? What are the major functions it is involved with?
G protein class: Gq; Major functions: Sympathetic NS. Increases vascular smooth muscle contraction (increases BP) , increase pupillary dilator muscle contraction (mydriasis- dilated pupils), increases intestinal and bladder sphincter muscle contraction (prevents peeing and pooping)
alpha2 receptors: what is the G protein class? What are the major functions involved?
Gi protein; Functions: Sympathetic NS. decrease sympathetic outflow (negative feedback fxn), decrease insulin release, decrease lipolysis, decrease aqueous humor production, increase platelet aggregation
beta1 receptors: G-protein class? Major functions involved?
Gs protein; Functions: Sympathetic NS. increases heart rate and contractility (chronotropic and ionotropic) increases renin release (increases BP), increase lipolysis
Beta2 receptors: G-protein class? Major functions involved?
Gs protein; Functions: Sympathetic NS. vasodilation, bronchodilation, increase lipolysis and insulin release (to lesser degree than alpha2 decreasing lipolysis and insulin so there is a net decrease) decrease uterine tone (tocolysis), ciliary muscle relaxation (increases intraocular presssure), increase aqueous humor production
M1 receptor: G-protein class? Major functions involved?
Gq protein Functions: Parasympathetic - CNS and enteric nervous system
M2 receptor: G-protein class? Major functions involved?
Gi Functions: Parasympathetic NS. decreases HR and contractility of atria (inhibition of atrial nodal area)
M3 receptor: G-protein class? Major functions involved?
Gq Functions: Parasympathetic NS. increases exocrine gland secretions (lacrimal, salivary, gastric acid), increase gut peristalsis, increase bladder contraction (pee!), bronchoconstriction, increase pupillary sphincter muscle contraction (miosis), increase ciliary muscle contraction (accomodation)
M3 receptor: G-protein class? Major functions involved?
Gq Functions: Parasympathetic NS. increases exocrine gland secretions (lacrimal, salivary, gastric acid), increase gut peristalsis, increase bladder contraction (pee!), bronchoconstriction, increase pupillary sphincter muscle contraction (miosis), increase ciliary muscle contraction (accommodation)
D1 receptor: G-protein class? Major functions involved?
Gs Functions: Dopamine receptor. relaxes renal vascular smooth muscle -> allows for increased renal perfusion
D2 receptor: G-protein class? Major functions involved?
Gi Functions: Dopamine receptor. Modulates NT release, especially in the brain
H1 receptor: G-protein class? Major functions involved?
Gq Function: histamine receptor. “Allergy symptoms” Increases nasal and bronchial mucus production, increases vascular permeability, bronchiole constriction, pruritus, pain
H2 receptor: G-protein class? Major functions involved?
Gs Function: histamine receptor. Increases gastric acid secretion from parietal cells
V1 receptor: G-protein class? Major functions involved?
Gq Vasopressin (ADH) receptor. Increases vascular smooth muscle contraction (increase BP)
V2 receptor: G-protein class? Major functions involved?
Gs Vasopressin (ADH) receptor. Increases water permeability and reabsorption in collecting tubules of kidney (“V2 is found in the 2 kidneys”)
What induces cytochrome P-450?
Chronic alcohol use
St. John’s wort
Phenytoin
Phenobarbital
Nevirapine
Rifampin
Griseofulvin
Carbamazepine
“Chronic alcoholics Steal Phen-Phen and Never Refuse Greasy Carbs”
What are substrates of cytochrome P450?
Anti-epileptics, Theophylline, Warfarin, OCPs
What are inhibitors of cytochrome P450?
Acute alcohol abuse
Ritonavir
Amiodarone
Cimetidine
Ketoconazole
Sulfonamides
Isoniazid (INH)
Grapefruit juice
Quinidine
Macrolides (EXCEPT Azithromycin)
“AAA RACKS IN GQ Magazine
Which drugs are sulfa drugs? What are symptoms of sulfa allergies?
Probenecid
Furosemide
Acetazolamide
Celecoxib
Thiazides
Sulfonamide antibiotics
Sulfasalazine
Sulfonylureas
“Popular FACTSSS”
sulfa allergy symptoms: fever, UTI, Stevens- Johnson syndrome, hemolytic anemia, thrombocytopenia, agranulocytosis, urticaria (hives)
