All of the drugs Flashcards
Furosemide: drug class
Diuretic
Loop diuretic
Furosemide: MOA
- Inhibit Na+/K+/2Cl- (ascending loop of Henle)
- ↓Na, K, Cl reabsorption → retained in tubule → presented to distal nephron → retain H2O (dilute urine)
- ↑ max fractional excretion of Na+ to 15-25% filtered load
Furosemide: other effects
- ↑intrarenal PGE2 synthesis → ↑ renal blood flow
- Initial ↓ renal vascular resistance w/o changing GFR
- Anti inflammatory
- ↑ thoracic duct lymph flow (high dose)
- Bonchodilation in Hu, Eq, Guinea pigs
- ↑ renin secretion
- Initial direct effect on macula densa
- 6h 2nd effect to ↓ volume and activation of ∑ system
Furosemide: 1/2 life
1.5-3h
Furosemide: bioavailability
variable
- Incomplete 40-50%
- Eq: almost no PO
Furosemide: IV, IM, PO onset, peak, duration
IV: onset 5min, peak 20-30min, duration 2h
IM: onset 10-15min, peak 30min, duration 4-8h
PO: onset 30-60min, peak 1-2h, duration 6-8h
Furosemide: pharmacoK
Protein bound: 86-91%
[Kidney to plasma] = 5:1
Furosemide: excretion
45% bile, 55% urine
Furosemide: indications
CHF
Edema
Congestion
Hyper Ca2+
HyperK+
Oliguric renal dz
Furosemide CI
Renal failure
- ↓ renal clearance to 15%
- 1/3 of diuretic effect
- 2x serum ½ life
- Constant rate of diuresis
HypoNa, hypoK, hypoCl, hypoMg
Metabolic acidosis
Hypovolemia
HF w/o fluid retention
Nonketotic hyperglycemic state
Ergogenic blood lipid changes
Ototoxicity
Nursing
Furosemide: drug interactions
Aminoglycoside
Amphotericine B → nephro/ ototoxicity
NSAIDs → can ↓ effect
Not mix with acidifying solution
Furosemide: MOA ototoxicity
Electrolyte disturbance in endolymphatic system
Furosemide: storage
Protect from light
Room Temp
Poorly soluble in water: can be used in dextrose 5% (D5W), saline 0.9%, LRS → stability 8h
Torsemide: drug class
Loop diuretic: high ceiling
Torsemide: MOA
Inhibit Na+/K+/2Cl- (ascending loop of Henle)
Torsemide: other effects
K+ sparing
Anti aldosterone/ mineralocorticoid effect
- Inhibit aldosterone R: bind cytoplasmic fraction of kidney
Antifibrotic effect
- Mineralocorticoid R blockade in
- ↓ lysyl oxidase & collagen cross linking → correlates w myocardial fibrosis and ventricular stiffness
Vasodilatory
Coronary protective
Torsemide: moelcule
Lipophilic anilinopyrimidine sulfonylurea derivative
Unique chemical structure → not related to furo
10x more potent vs furosemide
Torsemide 1/2 life dogs
120min
Torsemide bioav dogs
80-100%
Torsemide IV, PO peak, onset, duration dogs
IV: [peak] 2-5min, peak effect 20-25min, duration 90min
- Low urinary excretion rate
PO: onset 20min, peak 2h, duration 12h
Torsemide PO peak, onset, duration cats
PO: onset 20min, peak 4h, duration 12h
Torsemide 1/2 life eq
9h
Torsemide PO peak eq
3h
Torsemide: studies in Hu and rats
differences in myocardial fibrosis in torsemide patients (vs furo + spiro)
Spiro: drug class
K+ sparing diuretic
Aldosterone
antagonist
Spiro MOA
Competitive inhibition of aldosterone by binding to R
Interfere with Na+ reabsorption → ↑ max excretion of Na+ to 2%
Preserve K+ excretion
Spiro PO onset/peak
Slow onset
Peak 2-3days
Spiro: metabolism
Extensively/rapidly metabolized
- Metabolites active but less potent
Spiro: indications
CHF
Hepatic cirrhosis (inhibit ascites)
Spiro: CI
Steroid-like effect
Facial dermititis
Antiandrogenic effects (Hu): gynecomastia, hisurtism, impotence
Spiro: drug interaction
Caution with K+ supplementation and NSAIDs
Hydrochlorothiazide: drug class
Thiazide diuretic
Hydrochlorothiazide: MOA
Inhibit Na+ reabsorption in distal tubule
- ↓ diuretic effect compared to loop diuretic → most H2O already reabsorbed in distal tubule
Hydrochlorothiazide: other effects
Can lead to hypoK+
Can ↑ effect of other diuretic and anti-hypertensive agents
Will block region where hypertrophy occurs during long term use of loop diuretics
Hydrochlorothiazide: PO onset/peak/duration
PO:
- Onset 1-2
- Peak 4h
- Duration 12-24h
Hydrochlorothiazide: features
Low ceiling diuretic: max response reached at low dose
Hydrochlorothiazide: indications
CHF/edema
→ chronic use of diuretics
Antihyper-tensive
Ca2+ excretion (Ca2+ oxalate urolithes)
Hydrochlorothiazide: CI
Renal failure/azotemia: marked ↓ effect
HypoK+, hypoNa+
HyperCa2+
Ventricular arrhythmias: ↓K+, Mg2+
Proarrhythmic drugs
Pregnancy:
- ↓ circulating volume
- Cross placental barrier
Sulfonamide type IM side effects: hepatic jaundice, pancreatitis, blood dyscrasia, angiitis, pneumonitis, interstitial nephritis, photosensitive dermatitis
Diabetogenic effects: ↑ risk of new diabetes
Urate excretion and gout: ↓ urate excretion + ↑ blood uric acid
Atherogenic changes in blood lipids: ↑ LDL cholesterol and triglycerides
Hydrochlorothiazide: drug interactions
Steroids: salt retention → ↓ effect
Indomethacin/ NSAIDs → interfere w PG → ↓ effect
Antiarrhythmics: class IA or III → prolong QT
Nephrotoxic ATB
Probenecid (gout tx) → block effect
Enalapril: drug class
ACEi
Enalapril: MOA
Block conversion of AngI → Ang II by binding AngI site on ACE
Effects of decr Ang II
- ↓ vasopressor effect
- ↓ H20/Na+ retention
o ↓ aldosterone release from adrenal gland
o ↓vasopressin (ADH) release from posterior pituitary - ↓ central/peripheral ∑ tone
- ↓ GFR preservation when ↓ blood flow
- ↓ myocardial hypertrophy/remodel
o ↓AngII
o ↑ [bradykinin] - ↓ myocardial collagen synthesis and ↑ degradation → prevent fibrosis from AngII/aldosterone
Enalapril: other effects
Mild vasodilator (arterial + venous)
- ↓SVR by 25-30% (↓afterload) → ↑SV and CO
- ↓venous tone: ↑ peripheral circulation, ↓PCWP, LV, LAP
Enalapril: affinity
ACEi > AngI
- 200 000x greater
Enalapril: 1/2 life
½ life = 7-8h initially, 11-19h additive
Enalapril: PO peak/duration
Peak 2-4h
Duration 12-24h
[Steady state] in 4days
Enalapril: bioav
Bioav. 60%
- Well absorbed by GI tract
Enalapril: metabolism
Metabolized in liver → become pharmacologically active
Secreted by kidneys
Enalapril: indications
Hypertension
CHF
Asympto patients w LV dysfct → can ↓ development of CHF (Hu)
Enalapril: CI
Pregnancy
RA stenosis
HyperK+
Renal dz
Angioedema
Hypotension
Enalapril: side effects
Damage to kidneys confined to proximal tubules
- Juxtamedullary region of cortex
- Necrosis of tubular cells
Regeneration possible
2 studies
- Lower incidence of azotemia in enalapril group
- Enalapril had no effect on [creatinine]
Effects on kidney thought to be mainly from ACEi 2nd hypotension → ↓ renal blood flow and GFR
Benazepril: drug class
ACEi
Benazepril: MOA
Same to enalapril
Benazepril: molecule
Non sulfhydryl ACEi
Benazepril: peak
1-3h
Benazepril: 1/2 life
22h
Benazepril: metabolism
Metabolism: liver → hydrolysed into benazeprilat to become active
Excretion: bile and urine
- Less dependent on kidneys
Benazepril: indications
Same enalapril
Nitroprusside: drug class
Vasodilator
Nitroprusside: MOA
NO formation → stimulate guanylate cyclase → ↑cGMP → vascular SM relaxation
Nitroprusside: Other effects
Arteriole: ↓SVR → ↑SV and CO
Venous: ↓PVR, ↑peripheral flow, ↓ cardiac volume, ↓ venous P
May ↑ LV compliance
↓LVP diastolic and end diastolic
↓LAP, LAD and LV diameter
Nitroprusside: molecule
NO compound w/o ester bound
- Release NO when non enzymatically metabolized
Nitroprusside: onset/duration IV
Rapid onset (almost immediate)
Duration: min
Nitroprusside: absorption
well GI
Nitroprusside: metabolism
Metabolism: hepatic → rapidly by nitrate reductase to <10%
- Rarely used PO
Nitroprusside: indications
Acute CHF
Hypertension
Nitroprusside: CI
Hypotension
Cyanide toxicity
Venous hyperO2
Lactic acidosis
Dyspnea
Nitroprusside: storage
*protect from light
Expensive!
Nitroprusside: other effects
*Tolerance does not develop
- Reflex ↑∑ drive can occur
Nitroglycerine: drug class
Vasodilator
Nitroglycerine: MOA
NO formation → stimulate guanylate cyclase → ↑cGMP → vascular SM cell relaxation
Nitroglycerine: other effects
Blood volume redistribution: central → peripheral
↓intraventricular pressure → ↓ edema
↓SVR → ↑ SV, ↓LAP, ↓edema
Nitroglycerine: molecule
Ester of NO
- Parent compound: 10-14x more potent
Nitroglycerine: 1/2 life
1-4min
Nitroglycerine: absorption
well GI
Nitroglycerine: metabolism
Metabolism: hepatic → rapidly by nitrate reductase to <10%
Rarely used PO
Nitroglycerine: indications
CHF
PH
Angina pectoris (Hu)
Laminitis (Eq) → ↑ blood flow to feet
Nitroglycerine: CI
Hypotension
MetHb
Tolerance
Dobutamine: drug class
inotrope +
Dobutamine: MOA
β1 = β2 > α1 agonist
Bind D-1R in kidneys → vasodilation
Dobutamine: molecule
Biosynthetic precursor of NE → stimulates NE release
Dobutamine: effect depends on
Low doses: inotropic effect + ↓ SVR
High doses: ↑SVR as action on lower affinity αR
Dobutamine: 1/2 life
½ life = 1-2min
- Rapid clearance
Dobutamine: pharmacoK
Plateau [CRI] achieved in 8min
Dobutamine: w/ tachycardia
*Inotropic effects w/o tachycardia
Dobutamine: indications
Acute CHF
Cardiogenic shock
Acute renal failure
Dobutamine: CI
Arrhythmias
Hydralazine: drug class
Vasodilator
Hydralazine: MOA
↑ [prostacyclin] → direct arteriolar SMcells
Hydralazine: other effects
↑ Ao compliance
↓ SVR by 40% and in vascular beds:
- Renal
- Coronary
- Cerebral
- Mesenteric
> skeletal
No effect on systemic venous tone
↑ contractility: reflex from NE release → histamine release
Hydralazine: metabolism
Metabolism: hepatic 1st pass → acetylation
Hydralazine: onset/peak/stability
Onset: 30min-1h
Peak 3h
Stability 8-10h
Hydralazine: When used for systemic hypertension w/o heart dz
- Reflex ↑∑ tone → ↑ contractility and HR → ↑CO → stable BP
- Addition of β-blocker blocks reflex
Not seen with CHF: ↓ response to ∑ tone
Hydralazine: indications
Systemic hypertension
Cases refractory to ACEi
Regurgitation/ shunt refractory to tx
Hydralazine: CI
Renal failure: affect hepatic metabolism →↑ [plasma]
Hypotension
Anorexia
Vomiting
Diarrhea
Systemic lupus erythematosus
Fever
Peripheral neuropathy
Hydralazine: drug interactions
Can ↑ furo delivery to nephron → ↑ GFR