Dyspnea Associated with Ticagrelor

Ticagrelor is an antiplatelet medication that is commonly used for a number of cardiovascular conditions.  Its mechanism is similar to that of antiplatelet medications clopidogrel and prasugrel in that it inhibits P2Y12 ADP receptors on platelets, preventing platelet activation and aggregation.  Ticagrelor is different from clopidogrel and prasugrel in that it binds reversibly to the receptor and, importantly, it is administered as the active compound.  This contrasts with clopidogrel and prasugrel which require metabolic activation by CYP450 enzymes and are therefore susceptible to drug interactions and altered activation in those with polymorphic CYP450 phenotypes (clopidogrel requires two CYP450 enzyme steps for

Thiamine deficiency and supplementation in heart failure

Thiamine is a water-soluble vitamin that is an important coenzyme for various metabolic processes in the body.  These include the regulation of glucose metabolism, the Krebs cycle (generates ATP), the pentose shunt (generates NADPH), and maintenance of sodium/potassium gradients in the brain (necessary for conducting nerve impulses).  Thiamine is mostly obtained from dietary intake with absorption occurring in the jejunum and ileum. After traveling to the liver, thiamine spends a relatively short amount of time in the blood before distributing to tissues throughout

Beers Criteria Update 2023 - Seven Changes

The American Geriatrics Society (AGS) 2023 updated AGS Beers Criteria® for potentially inappropriate medication (PIM) use in older adults was released during the AGS annual meeting in May 2023.  This is the sixth update to the criteria which are currently designed to identify potentially inappropriate medications (PIMs) that are best avoided in older adults in general or in specific circumstances.  The criteria were first intended to be applied to the nursing home population but were expanded to apply to all adults 65 years old and older (except for end-of-life settings). 

Sulfamethoxazole/trimethoprim and increase in serum creatinine: When to be concerned

A 65 year old male is being treated for an infection on his forearm that developed purulent drainage within the last few days.  He denies experiencing any penetrating trauma to his arm and denies any other complaints at this time.  He weighs 70 kg, His WBC count is 14.7 x 109/L, serum creatinine is 1.3 mg/dL, and his vital signs are within normal limits.  His past medical history includes hypertension and an MRSA infection last year.  He is currently taking valsartan 160 mg daily and chlorthalidone

Inhaled isopropyl alcohol for nausea

An elderly male presents to the emergency department with complaints of nausea, vomiting, and diarrhea starting a day and a half ago.  The diarrhea started abruptly, has occurred almost 10 times, and is non-bloody.  His abdomen is soft but has mild diffuse tenderness.  Vital signs and basic laboratory results are normal except for a potassium of 2.9 mEq/L and an EKG with a QTc interval of 490 msec. 

"How it works" series: Midodrine

Midodrine is a peripherally-acting selective alpha1 receptor agonist.  Let's take that sentence apart to see what we should expect from this medication.  Being an alpha1 agonist, this means that it binds to the alpha1 receptor and activates it, causing it to perform the function that it would usually perform if its endogenous catecholamine (ie. norepinephrine) were to bind to it.