Respiratory SketchyPharm

Question 1

What is the mechanism of action of alprostadil and its indications?

Answer 1

PGE1 analog - think of the guy with the dill pickle skateboard

Indications:

1. Maintains patency of the ductus arteriosus - think of the ductus above (PGE2 is physiologically important for this)
2. Erectile dysfunction - Think of the kid wielding the erect proslugger bat

Question 2

Why are NSAIDs not the best in pregnancy?

Answer 2

At least in the third trimester, inhibition of prostaglandin synthesis can lead to closure of the ductus arteriosus

Question 3

Other than protection of the GI mucosa when COX-1 is inhibited, what is the other indication for misoprostol? What is it an analog to?

Answer 3

Stimulation of uterine contractions / labor
-> remember prostaglandins play an important function in the initiation of labor

Similar to alprostadil, it is a PGE1 analog

• > they are under the “E”xtreme sports section
• > guy is playing sports with swing / misoprostol

Question 4

What are dinoprostone and carboprost analogs of and used for?

Answer 4

Think of the guy with the dino hat in the extreme sports section - PGE analog. He is holding a uterus bag.
-> Dinoprost used for ripening of the uterus / stimulation of uterine contraction

Carboprost - think of cardboard box kid in the “F”ootwear section. PGF2alpha analog
-> Used for uterine contraction but also control of uterine bleeding by clamping down on blood vessels

Question 5

What are the two prostaglandin analogs used to increase aqueous humor outflow in glaucoma and what is they analogs of? side effect?

Answer 5

Footwear section - PGF2alpha analogs

1. Latanoprost
2. Travoprost - think world traveler footwear

Brown iris pigmentation - Think of the kid wearing the brown sunglasses

Question 6

What are the first line agents in the treatment of pulmonary hypertension? What is their mechanism?

Answer 6

Think of the prostacyclin procycler with high and low settings - PGI2 analogs

Iloprost - iLow
Epoprost - ePro

Direct vasodilatory effects on pulmonary / systemic vasculature + inhibition of platelet aggregation

Question 7

What are the PDE-5 inhibitors which can be used to treat pulmonary HTN?

Answer 7

1. Sildenafil
2. Tildalafil
   - > increase cGMP causing dephosphorylation of MLC -> vasodilation

These are also used in the treatment of erectile dysfunction

Question 8

What is the mechanism of bosENtan in the treatment of pulmonary HTN?

Answer 8

End of the line - endothelin inhibitor
Endothelin normally stimulates vasoconstriction / endothelial proliferation
-> toxicity: Think of boss-man stan with the liver-shaped spot
-> monitor LFTs for fatal hepatotoxicity

Question 9

What type of receptor do H1 / H2 utilize? What does activation of thhese receptors do?

Answer 9

H1 - Galpha-Q - think of the guy holding the Q-shaped dandelion
-> increases Ca+2 -> contraction of the postcapillary venules for fluid release, also stimulates bronchoconstriction
H2 - think of the honeypot with two S handles on it.
-> increases cAMP -> increased activation of H/K-ATPase in parietal cells

Question 10

What is the mechanism of action of meclizine in the treatment of motion sickness and why can it do this when cetirizine cannot?

Answer 10

Think fairy cuiZINE

• > H1 receptor antagonist
• > meclizine is much more lipophilic than cetirizine and can thus easily cross the BBB

Question 11

Why might 1st generation antihistamines be useful in the treatment of Parkinson’s disease?

Answer 11

They possess anticholinergic (anti-muscarinic) side effects -> can restore the cholinergic / dopamine balance in the basal ganglia

Question 12

Why do 1st gen antihistamines cause sedation and weight gain? Do they cause any other side effects?

Answer 12

Think of the serotonin smiley cake with a piece taken out of it
-> they antagonize serotonin receptors -> decreases your satiety -> increases appetite and weight gain

Also think of the blown out alpha1 candle on the cake
-> can cause orthostatic hypotension and dizziness

Question 13

What is the most potent bronchoconstricting leukotriene and what blocks it?

Answer 13

LTD4

CysLT1 receptor blockers (LTD4 receptor):

1. Montelukast
2. Zafirlukast

Thank of the “caster” blocking the lacrosse goal

Question 14

What is the main advantage of the CysLT1 receptor blockers and what types of asthma are they especially good for?

Answer 14

They are orally taken agents - good for those poorly compliant with inhaled therapy
Good for:
1. Aspirin-induced - arachidonic acid diverted to leukotriene pathway
2. Exercise-induced asthma - just remember the lacrosse players

Question 15

What is the mechanism of action of Zileuton? Side effect?

Answer 15

Direct inhibitor of 5-Lipoxygenase -> first step in leukotriene synthesis pathway

Think of god”zil”la about to attack the lacrosse coach

Side effect: Think of the liver spot on godzilla

Question 16

What is the mechanism of action of theophylline and the potential toxicities?

Answer 16

Methylxanthine phosphodiesterase inhibitor
-> increases cAMP

Think of all the effects of caffeine, an adenosine antagonist

• > neurotoxic - seizures, tremors, anxiety
• > cardiotoxic - arrhythmia, tachycardia, cardiac arrest

Question 17

What drugs can interact with theophylline?

Answer 17

It has a narrow therapeutic window and is metabolized by the CYP450 system, similar to warfarin

-> any drug that inhibits CYP450 can lead to toxic accumulation

Question 18

What is the monoclonal antibody used in the treatment of asthma and its very specific mechanism of action?

Answer 18

Omalizumab - limosine

Binds to the Fc!! portion of IgE -> the part that is supposed to bind mast cells

Question 19

What bronchodilators are used second line for the treatment of asthma, and even in an asthma exacerbation?

Answer 19

Ipratropium (short-acting) and tiotropium (long-acting)

-> muscarinic antagonists