Topic list A drugs Flashcards
Drugs acting on GI and UroG SM by inducing smooth muscle relaxation (5)
- Papaverine
- Drotaverine
- Butyl-scopalamine
- Solifenacin
- Oxybutynin
Tocolytic drugs - that relax the pregnant uterus (4)
- Atosiban
- Terbutaline
- Mg2+
- Ethanol
Drugs that contract the pregnant uterus (3)
- Oxytocin
- Ergotamine
- Misoprostol
Agents acting on the male reproductive system
Tamsulosin
1st generation H1 receptor antagonists
- Diphenhydramine
- Dimetindene
- Promethazine
2nd generation H1 receptor antagonists
- Levocetirizine
- Desloratadine
- Fexofenadine
Papaverine, drotaverine
- MOA
- Indication
- Side effects
- ROA
- Calcium channel blockers and non selective phosphodiesterase inhibitor
- GI and urogenital spasm
- Hypotension, arrythmias, hepatotoxicity
- Oral and parenteral
Butyl-scopalamine
- MOA
- Effect
- Indications
- Non-selective muscarinic antagonist
- SM relaxation (GI!)
- Pain and discomfort caused by abdominal cramps or urinary tract spasms
Difference between butyl-scopalamine and scopalamine
Butyl-scopalamine has no CNS effects
Solifenacin, oxybutinin
- MOA
- Effects
- ROA
- Extra
- Selective muscarinic antagonist : M3 (Gq receptor -> contraction)
- Relax the muscles in the wall of the bladder and decrease detrusor muscle spasms
- Oral or transdermal patch
- Short acting
Atosiban
- MOA
- Indication
- Side effects
- ROA
- oxytocin receptor antagonist (Gq receptor)
- Prevents premature labor
- Increased rates of infant death
- IV
Terbutaline
- MOA
- Effect
- Indication
- Side effect
- ROA
- Short acting B2 agonist (Gs coupled)
- Uterus relaxation (and bronchodilation)
- To prevent premature labor (from 16th week)
- Arrythmias
- Aerosol inhalation, oral, parenteral
Mg2+
- MOA
- Indication
- Side effects
- ROA
- Calcium channel blocker
- To relax the uterus
- Maternal SE : flushing, lethargy, pulmonary edema, cardiac arrest
- Neonatal SE : hypotension, respiratory depression
- ROA : IV
MOA of oxytocin
Oxytocin receptor is GQ coupled
Oxytocin
- Effect
- Indication
- SE
- ROA
- Contraction of uterus and of the myoepithelial cells of the breast
- Induction of labor, decrease of postpartum hemorrhage, induction of lactation
- Fetal distress, placental abruption, uterine rupture, hypervolemia (4)
- IV, intranasal
Ergotamine
- MOA
- Effect
- Indication
- Contraindication
- Side effects
- ROA
- alpha 1 (Gq coupled) and 5HT-R agonist
- Induce vasoconstriction and uterine contraction
- To prevent postpartum uterine hemorrhage
- HT, pregnancy
- Increased BP, angina
- Parenteral
Misoprostol
- MOA
- Effect
- Indication
- Side effects
- ROA
- Prostaglandin E1 analog (Gq)
- Uterus contraction, gastric mucus secretion
- For abortion or to induce labor + postpartum hemorrhage
- Bleeding
- Oral
Tamsulosin
- MOA
- Effect
- Indication
- ROA
- Alpha1 selective antagonist (Gq coupled)
- Relax the muscles of the prostate + bladder neck
- BPH, hypertension
- Oral
Diphenhydramine and dimetindene
- MOA
- Effects
- Indication
- H1 (1st generation), Alpha1-AR, muscarinic, and serotonergic antagonist
- Decreases vascular permeability and nasal and bronchial mucus secretion + causes bronchorelaxation
- For IGE mediated allergies, asthma bronchiale and anaphylaxis mainly. Nausea, vomiting, dizziness, anorexia sometimes.
Side effects of diphenhydramine and dimetindene
- Sedation, cognitive impairment
- Antimuscarinic : dry mouth, blurred vision, glaucoma exarcerbation
- Antiadrenergic : hypotension
Indication of 2nd generation H1 receptor antagonists
IGE mediated allergies (hay fever, urticaria…)
Side effects of 2nd generation H1R antagonists
Sedation and K+ channel inhibition at high doses
What is the action of fampridin (4-aminopyridin)?
It binds to M2 and blocks K+ channels when in the open position, which causes the depolarization to last longer and helps propagation in demyelinised axons
What is the effect of the botulinum toxin on cholinergic transmission?
It inhibits the terminal calcium channel, which stops the signal for vesicular release
Levodopa
- MOA
- Effect
- Indication
- Side effects (5)
- Metabolic precursor of dopamine
- Increases the activity of DOPA-decarboxylase
- Parkinson’s disease
- Dyskenia, hypotension, arrythmias, nausea, depression
What is the effect of carbidopa?
It inhibits DOPA-decarboxylase and prevents synthesis of dopamine peripherally
What is the effect of metyrosine
Inhibits synthesis of DOPA from tyrosine
Cholinomimetics that are direct muscarinic and/or nicotonic agonists
- carbachol
- pilocarpine
Cholinomimetics that are indirect agonists
- Neostigmine
- pyridostigmine
- rivastigmine
Carbachol
- MOA
- Effect
- Muscarinic and nicotinic agonist
- Miosis via ciliary muscle contraction (M3) and decreased intraocular pressure
What is the MOA of pilocarpine?
Direct muscarinic agonist
What is the effect of pilocarpine?
Increases salivation and sweat production
What are the indications of neostigmine and pyridostigmine?
Reverse the effects of relaxants and for treatment of myasthenia gravis
What is special about neostigmine and pyridostigmine?
They are quaternary amine and do not cross the BBB
Rivastigmine
- MOA
- Indication
- Side effects
- Cholinesterase inhibitor
- For the treatment of mild dementia of alzheimer type
- Nausea, vomiting, bradycardia
8 examples of muscarinic antagonists (receptor blocking)
- Atropine
- Butyl-scopalamine
- Procyclidine
- Cyclopentolate
- Ipratropium
- Tiotropium
- Solifenacin
- Oxybutinin
at pro cyclist tournaments, i solely binge oxy
Which muscarinic receptor blocking drugs are selective?
Tiotropium, solifenacin and oxybutinin are selective M3 antagonists
How is butyl-scopalamine different from scopalamine?
It cannot enter the CNS
Procyclidine
- MOA
- Indications
- Muscarinic receptor antagonist
- Parkinson’s disease (increase in Ach due to decrease in dopamine)
- Extrapyramidal disorders caused by drugs
Can procyclidine enter the CNS?
Yes, it has a tertiary amine
What is the indication of cyclopentolate?
It is used to dilate the pupils in ophtalmologic examinations
ipratropium and triotropium
MOA
Effect
ROA
- Muscarinic antagonist
- Bronchodilation
- Inhaled from a spray
MOA of epinephrine (small and large dose)
- Small dose : B stimulation predominates
- Big dose : A1 stimulation predominates
Epinephrine doses
- Anaphylaxia : 0.15-0.5mg or 0.05-0.1mg in IV
- Resuscitation : 1mg IV
Norepinephrine
- MOA
- Effect
- Indications
- a1, a2 and b1 agonist
- Vasoconstriction
- Acute hypotension in shock + cardiac arrest / complete heart block
MOA of dopamine (small, medium and large dose)
- small : D1 - vasodilation, increase in GFR
- medium : D1, b1 - positive inotropic & chronotropic effect
- large dose : a1 effect - vasoconstriction
Indications of dopamine (3)
- Shock
- Renal insufficiency
- Heart failure
Dobutamine
- MOA
- Effect
- b1 agonist
- Cardiac Output and Stroke Volume increase
Isoprenaline
- MOA
- Effect
- Contraindications
- Non selective b-agonist (it’s one of the catecholamines)
- Positive inotropic and chronotropic effect via b1+ bronchodilation via b2
- Underlying coronary disease
Ephedrine
MOA
Indications (3)
- Indirect sympathomimetic + weak b2 agonist
- Nasal decongestant + Treatment of anesthesia related hypotension + Appetite suppressant
Phenylephrine
- MOA
- Indications (3)
- a1 agonist
- Hypotension, nasal decongestion, mydriasis for ophtalmologic examination
MOA of oxymetazoline
- Local a1 agonist
- Systemic a2 agonist
Clonidine
- MOA
- Effects
Indications (3)
- a2 agonist (Gi coupled - inhibitory)
- Presynaptic a2R leads to decrease in release of NE and thus a decrease in BP
- Hypertension, Tourette’s, ADHD
MOA of Rilmenidine
A2 agonist
Methyldopa
- MOA
- Extra
- A2 agonist
- It can be used even during pregnancy because it can’t activate other adrenergic receptors
3 a1-selective antagonist drugs
- Prazosin
- Doxazosin
- Tamsulosin
Effect of prazosin, doxazosin, tamsulosin
Relax muscle of prostate + bladder neck
MOA of urapidil
- a1 selective antagonist
- a2 agonist
- b antagonist
Carvedilol
- MOA
- Indications
- a1 selective antagonist and b antagonist
- Hypertension, CHF, chronic stable angina
(It decreases HT through alpha and reduces tachycardia, heart problems through beta)
Phentolamine
- MOA
- Effect
- Indication
- Non selective a-antagonist
- Vasodilation
- Treatment of pheochromocytoma & acute hypertension due to a-agonist overdose
4 non-selective beta antagonists
- Propanolol
- Pindolol
- Timolol
- Sotalol
4 beta1-selective antagonists
- Bisoprolol
- Metoprolol
- Esmolol
- Nebivolol
Indications for b1-selective antagonists
- Hypertension
- Chronic stable angina
- CHF
Dosage of metoprolol
2x25-100mg
Which b-selective antagonists cross the BBB?
Bisoprolol and nebivolol because they are lipophilic
Which local anesthetics are amides?
- Lidocaine
- Articaine
- Bupivacaine
Which local anesthetics are esters?
- Cocaine
- Benzocaine
What is the MOA of local anesthetics?
Na+ channel blockers
Lidocaine
- Indications (3)
- Duration of action
- Local surgical procedures, post operative analgesia and ventricular arrhythmia
- 1-2 hours, 2-4 hours if combined with epinephrine
Cocaine
MOA
Effect
- binds and inactivates sodium channels, which inhibits excitation
- blocks NE reuptake into nerve terminals because of its vasoconstrictive properties : intrinsic sympathomimetic effect
Effect of benzocaine
Reversibly stabilizes the neuronal membrane - decreases its permeability to Na ions : anesthetic
What type of receptors are the opioid receptors?
They are all Gi coupled
What is the MOA of morphine?
Strong opioid receptor agonist
Cite 6 main effects of morphine
- Analgesia
- Respiratory depression
- Decreased BP + bradycardia
- Nausea, vomiting
- Bronchoconstriction
- Urinary retention & constipation
Dosage of morphine (per os / sc / iv)
- Per os : morphine sulfate - 2x 30-100mg
- Sc : morphine hydrochloride - 10-20mg
- IV : morphine hydrochloride - 1mg (repeated up to 10mg)
Codeine
- MOA
- Effects
- Weak agonist of MOR - mu opioid receptor
- Antitussive and weak analgesic effect
Aspirin / acetylsalicilic acid
- MOA
- Effect
- Side effects (4)
- Irreversible COX inhibitor
- Inhibition of COX enzyme in platelets decreases thromboxane A2, which decreases platelet aggregation
- Bleeding, peptic ulcers, hypersensitivity reaction, respiratory alkalosis -> respiratory acidosis