Drugs in Red Exam 4 Flashcards
Serotonin
- 5-HT, Indoleamine
- Endogenous, monoamine neurotransmitter in CNS
- Regulator of smooth muscle function in CV and GI
- Regulates platelet function
Isoproterenol
- Synthetic catecholamine
- B1/B2 selective
- Bronchodilator and inotrope
- Used for cardiac benefits: mild/transient episodes of heart block that doesn’t need a pacemaker or electric shock, cardiac arrest, cardiac catheterization (B1)
- Also used to bronchospasms during anesthesia (B2)
L-DOPA
- product from tyrosine hydroxylase
- AKA dihydroxyphenylalanine
- Decarboxylated by aromatic L-amino acid decarboxylase to form dopamine
- Also used in the formation of histamine, GABA, and 5-HT
Dopamine (DA)
- Stored in vesicles
- Converted to NE by membrane bound dopamine B-hydroxylase
- Ascorbic acid is cofarctor needed in this conversion
- Can’t cross BBB
- IV Infused
- Metabolized by MAO and COMT, about 25% converted to NE
Norepinephrine (NE)
- Neurotransmitter in most postganglionic SNS neurons
- Stimulates Alpha 1 (vasoconstricts), alpha 2 (feedback inhibition), and beta 1 receptors (increase HR/contractility)
- Increases systolic and diastolic BP
- Ineffective orally, only IV route
- Short duration, rapid metabolism by MAO and COMT in liver and reuptake at the synapse
- Can’t cross BBB
Epinephrine (EPI) - Synthesis, Storage, General Effect
- Adrenalin
- NE converted to this in chromaffin cells in the adrenal medulla
- Conversion done by PNMT which is induced by corticosteroids
- Cofactor for this conversion is S-adenosylmethionine
- Stored in chromaffin granules for release (endocrine hormone)
- Stimulant of alpha and beta receptors (no specification)
- Causes fight or flight response (know all of beta 1-3 and alpha 1 response in fight or flight)
- Can’t cross BBB
Reserpine
- Inhibits VMAT transport that brings catecholamines into their vesicles
- This depletes catecholamines stores from their nerve terminals
- Irreversible inhibition
- Requires new vesicles to be synthesizes which can take days to recover
- Newly synthesized catecholamines metabolized by MAO since VMAT blocks their storage (protection)
- Depletes NE, DA, and 5-HT
Tyramine
- Indirect acting sympathomimetic
- Taken up by uptake transporters and indirectly release NE
- Compete for vesicular uptake which displaces stored NE
- Makes a carrier available at the inner surface to facilitate exchange diffusion of NE out of vesicle
- No calcium is required, no ATP or DBH is released (nonvesicular release)
- Repeated tyramine administration yields tachyphylaxis - decreased postsynaptic response
- *Need catecholamines to produce their effects**
Ephedrine
- Indirect acting sympathomimetic
- Also direct acting on B2
- Taken up by uptake transporters and indirectly release NE
- Compete for vesicular uptake which displaces stored NE
- Makes a carrier available at the inner surface to facilitate exchange diffusion of NE out of vesicle
- No hydroxyl groups on ring, can cross BBB
- No calcium is required, no ATP or DBH is released (nonvesicular release)
- *Need catecholamines to produce their effects**
Tranylcypromine
- Parnate
- MAO-A and B inhibitor
- Used to treat depression
- MAO-A prefers 5-HT and NE
- Irreversible inhibition
- Also used to treat hypertension
- WARNING: “Wine and Cheese Effect” MAO metabolizes tyramine from diet, when blocked if excess tyramine is ingested hypertensive crisis can occur due to tyramine releasing NE
Selegiline
-Eldepry
-MAO-B inhibitor
-Used to treat Parkinson’s disease
-MAO-B prefers dopamine
-Irreversible inhibition
Also used to treat hypertension
-WARNING: “Wine and Cheese Effect” MAO metabolizes tyramine from diet, when blocked if excess tyramine is ingested hypertensive crisis can occur due to tyramine releasing NE
Tolcapone
- Tasmar
- COMT Inhibitor
- Adjunct therapies for Parkinson’s disease to prevent dopamine metabolization
- Can possible help reduce the dose of L-DOPA administered
- Act mainly in liver, kidney, and BBB
- Little effect on endogenous catecholamines at synapse
Entacapone
- Comtan
- COMT Inhibitor
- Adjunct therapies for Parkinson’s disease to prevent dopamine metabolization
- Can possible help reduce the dose of L-DOPA administered
- Act mainly in liver, kidney, and BBB
- Little effect on endogenous catecholamines at synapse
Dobutamine
- Beta 1 agonist
- Dobutrex
- Increases contractility and chronotropic effects - increase CO
- Only elevates systolic BP
- Diastolic BP and mean arterial pressure are unchanged
- No effect on DA receptors
- IV Infused
Metoprolol
- Lopressor
- Beta 1 antagonists, competitive
- Used for acute MI (IV), hypertension, angina, and migraine prophylaxis, cardiac arrhythmias related to rapid HR and conduction problems
- Used in cardiology in mild to severe CHF (start at low dose and titrate up)
- Combine with Bisoprolol and Carvedilol to improve injection fraction, slow heart failure, decrease number of deaths/hospitalizations
Terbutaline
- Brethaire
- Short-acting Beta 2 agonist
- Tablet or parenterally (S.C)
- Used to reverse acute bronchospasm in asthma and COPD
- Off label use - delay/prolong premature labor, don’t use beyond 48-72 hours since this can cause serious maternal heart problems and death
Phenyleprine
- Neosynephrine
- Alpha 1 agonist
- Potent vasoconstrictor
- Tablets, liquid, nasal sprays
- Combined use with antihistamine, dextromethorphan, acetaminophen
- Metabolized by MAO in liver and intestine
- Therapeutic uses: Nasal congestion in cough, cold, and allergy medications
Prazosin
- Minipress
- Selective Alpha 1 antagonists
- Reduces BP supine or standing, effects diastolic more
- Used to treat hypertension, hypertensive emergency, Raynaud’s disease, frostbite
- Side effect: syncope with first dose, enhanced vasodilation when given with PDE-5 inhibitors
Clonidine
- Catapres
- Alpha 2 agonist
- Major side effect is sedation
- Impaired the response to acute glucose challenge in mildly hypertensive, type II diabetic patients
- Doesn’t adversely affect diabetic control over 10 weeks
- Epidural, oral, patch
- ER: Kapvay; Used for ADHD
- Can be used monotherapy or as an add-on for ADHD
- Withdrawal: rebound hypertension
Yohimbine
- Alpha 2 antagonists
- Effective drug in patients with type II diabetes who have a variant gene ADRA2A
- About 40% of type II diabetic patients have this gene which makes insulin-releasing cells in the pancreas more sensitive to inhibitory effects on insulin release by the stress hormone adrenaline
- New therapeutic option for this subset of people
Alpha-methyldopa
- Aldomet
- Oral, parenteral
- Treats moderate to severe hypertension
- Forms a false transmitter that displaces NE in synaptic vesicles
- Decarboxylated to methyl dopamine and hydroxylated to methylNE
- Therapeutic antihypertensive effects by activating alpha-2 receptors in CNS
- Black Box Warning: Methyldopa + HCZ - not indicated for initial hypertension therapy
Carbidopa
- Lodosyn
- Derivative of methyldopa
- Inhibits aromatic amino acid decarboxylase
- Doesn’t cross BBB
- No major effect on endogenous catecholamine synthesis within neuron (effects non-rate limiting step)
- Inhibits conversion of exogenous L-DOPA to dopamine outside of brain which occurs mainly in the liver
- Used in combination with L-DOPA to treat Parkinson’s
Guanethidine
- Ismellin
- Doesn’t enter CNS
- Taken up by NE neurons and depletes NE stores
- Prevents release of NE in response to action potentials/indirect acting sympathomimetics
- General reduction in sympathetic tone which can treat moderate to severe hypertension
Bretylium
- Acts like guanethidine
- IV injection
- Used in emergencies to treat ventricular arrhythmias
Amphetamine
- Rapid release of neurotransmitter that produces sympathomimetic effect
- Has no hydroxyl groups on ring so it can cross BBB
- Taken up by catecholamine uptake pump in exchange for cytoplasmic catecholamines
- Competes with and displaces endogenous catecholamines
- *Need catecholamines to produce their effects**
Amantadine
- Antiviral drug
- Promotes release of dopamine in brain
- Used in treatment of Parkinson’s
Cocaine
- CII
- Eurphoria and high abuse potential
- Prevents catecholamine reuptake by inhibiting uptake 1 pump
- Indirect sympathomimetic
- Drug of abuse
- High affinity for dopamine uptake pump
- Inhibits reuptake of NE, DA, and 5-HT
- Generalized sympathomimetic effect - Increased HR/BP
- Used as a local anesthetic on mucous membranes of oral, laryngeal, and nasal cavities
- Vasoconstrictor action from NE blockade to decrease bleeding
TCAs
- Tricyclic antidepressants
- Ex: amitriptyline
- Prevents catecholamine reuptake by uptake 1 pump
- Act on NE pump > 5-HT pump > DA pump
- No abuse potential
- Takes 2-3 weeks before antidepressant effects are apparent
Metoclopromide
- Reglan
- Dopamine D2 antagonist
- Blocks the dopamine inhibition of cholinergic activity
- Increases tone of lower esophageal sphincter
- Increases force of contraction
- Increases gastric emptying
- Effective antiemetic
Mirabegron
- Myrbetriq
- Beta 3 agonist
- Relaxation of detrusor muscle to help with urinary incontinence
- Adverse reaction: hypertension
- Combine with antimuscarinic if symptoms persist
Prostaglandins & Oxytocin
-Induce labor
Prostaglandins/Progesterone Antagonists
-Induce abortions
Apraclonidine
- Iopidine
- Opthalmic solution
- Alpha 2 selective agonist
- Decreases aqueous secretions
- Decreased CV side effects
- Similar uses to brimonidine but has a shorter duration
Betaxolol
- Betoptic S
- Selective beta 1 antagonist
- Decrease aqueous humor production from ciliary epithelium
- Minimal pulmonary/CV side effects
Timolol (Ophthalmic)
- Betimol
- Ophthalmic solution
- non-selective beta antagonist
- Decrease aqueous humor production from ciliary epithelium
- Caution use in those with pulmonary/CV problems
EPI PK
- Injection, inhalation, intranasal, or topical to eye
- Not effective orally - metabolized by liver
- Slow IV injection during CPR
- Emergency use
- Loses potency after expiration date due to tendency to auto-oxidize (turns pink/brown)
Ana-Kit
- Given SC, IM, or IV
- Given in bronchospasm, severe asthma exacerbation, and anaphylaxis (EPIPEN)
- Beta-2 activation therapeutic use of EPI
Racepinephrine
- Asthmanefrin
- OTC inhaler
- Temporary relief of mild symptoms of intermittent asthma
- Beta-2 activation therapeutic use of EPI
Vasopressin
- Used along with epinephrine and electrical defibrillation in CPR
- Constricts blood vessels to increase BP
- Alpha 1 effect (via EPI) and V1 receptor (via vasopressin)
- Increases cerebral and myocardial blood flow during CPR
Amiodarone/Lidocaine
- Antiarrhythmic drugs
- Used in CPR
Local Anesthetics
- Slows down absorption of anesthetic from site of injection, prolonging its effect
- Used with epinephrine (vasoconstricts via alpha 1 receptor) to treat or prevent surgical bleeding
- Decreases system toxicity
EPI Contraindications (5)
- Use with caution in those with hemorrhagic shock, cardiac disease with coronary insufficiency, cardiac arrhythmias
- Detrimental to above conditions since EPI increases myocardial oxygen demand, increases HR, has proarrhythmic potential, and produces vasoconstriction - Hypertension (alpha and beta effects)
- Hyperthyroidism (B1)
- Diabetes mellitus (hyperglycemia from B2 activation)
- Cerebrovascular disease - alpha 1 activation may cause cerebrovascular hemorrhage