Real Life Pharmacology - Pharmacology Education for Health Care Professionals

Metolazone (Zaroxolyn) is a thiazide-like diuretic. It promotes the loss of water and sodium through the kidney. The most common indication I see metolazone used for is for additional fluid loss in heart failure. Potassium must be monitored as it can cause significant hypokalemia which is exacerbated when metolazone is used in combination with loop diuretics. Hyperuricemia is a potential adverse e...

Ibandronate is a bisphosphonate that can be used in the management of osteoporosis. Bisphosphonates like ibandronate require a full glass of water for oral administration. Patients should remain upright for at least 30-60 minutes following taking ibandronate to help reduce the risk of esophagitis. Osteonecrosis has rarely been associated with bisphosphonates like ibandronate – I’ve dis...

Fluticasone, Umeclidinium, and Vilanterol is a combination medication used in the setting of COPD. I discuss the pharmacology of this agent further in this episode. Fluticasone is the inhaled corticosteroid portion of the drug while umeclidinium is a LAMA and vilanterol is a LABA medication. Drug interactions aren’t incredibly common or strongly clinically significant, but I discuss some of...

Hyoscyamine is an anticholinergic medication that is primarily used for GI problems like spasms and pain associated with IBS. Because of the highly anticholinergic nature of hyoscyamine, it can cause dry eyes, dry mouth, urinary retention, and constipation. Be aware of the risk for the prescribing cascade with hyoscyamine. Saliva substitutes for dry mouth, artificial tears for dry eyes, etc. Sedat...

Calcium Acetate (PhosLo) is used in the management of hyperphosphatemia associated with CKD. Important monitoring parameters for calcium acetate include phosphorus, calcium, PTH, and renal function. There are numerous binding interactions with calcium acetate. It can reduce concentrations of some HIV drugs, antibiotics, and thyroid supplements. I discuss more examples in the podcast. Thiazide diur...

Nortriptyline is a TCA that can be used for depression and various pain syndromes. I discuss other less common diagnoses in this podcast episode as well. There are a lot of drug interactions with nortriptyline. It is metabolized by CYP2D6, can have additive anticholinergic effects and has been associated with QTc prolongation. Nortriptyline is very anticholinergic and can blunt the effects of deme...

Hydroxychloroquine is classified as a DMARD and when used chronically, can be helpful in managing rheumatoid arthritis and Lupus. There have been reports of QTc prolongation with hydroxychloroquine. While not incredibly common, it is important to remember this consideration in patients at risk for QTc prolongation. Hydroxychloroquine is associated with causing retinopathy. Routine eye exams for mo...

Latanoprost is a prostaglandin F2 analog that can help reduce intraocular pressure and manage glaucoma. Excessive eyelash growth is a potential adverse effect of latanoprost, although some patients may appreciate this. Patients with a lighter color iris may notice that their eyes are turning more brown with the chronic use of latanoprost. Corticosteroids are known to increase intraocular pressure...

Terbinafine can inhibit CYP2D6 which plays an important role in the metabolism of many drugs such as metoprolol, fluoxetine, and clozapine. With terbinafine’s ability to inhibit CYP2D6, it can also increase the risk of treatment failure with drugs like tamoxifen. When using anti-fungal drugs like terbinafine, remember that fungal infections can often require more time to treat. Terbinafine h...

Alendronate is a bisphosphonate that is used in the management of osteoporosis. In this episode, I discuss osteonecrosis risk and what are some of the risk factors that may increase the chances of this very rare adverse effect. Binding interactions are so critical with alendronate. They can essentially make the drug useless. Esophageal irritation and ulceration is one of the possible complications...

Diazepam has numerous dosage forms. There are rectal, injectable, and oral formulations of the drug that are commonly used in clinical practice. Diazepam has 2 major metabolic pathways. It is broken down primarily by CYP3A4 and CYP2C19, leaving open the potential for numerous drug interactions. I discuss this further in the podcast. Diazepam is on the Beers list because it has a tendency to accumu...

Dicyclomine is an anticholinergic agent that is used to help manage GI pain associated with IBS. Dicyclomine has a very short half-life which means that it can be dosed multiple times per day. Be careful with patients who have predominant constipation with their IBS as dicyclomine can exacerbate this. Bentyl is the brand name of dicyclomine. This drug blocks the action of acetylcholine. I discuss...

Diltiazem is a non-dihydropyridine calcium channel blocker that can be used in atrial fibrillation as well as hypertension. One big downside to diltiazem is that it does have a few drug interactions via CYP3A4. Aripiprazole, apixaban, and certain statins are all examples of medication that can have concentrations increased by adding diltiazem to a patient’s regimen. Diltiazem works a little...

Zolpidem enhances the action of GABA which is an inhibitor neurotransmitter. Zolpidem metabolism can be impacted by the use of CYP3A4 inhibitors. Concentrations can rise on account of this potential interaction. It is important to remember to go slowly when tapering off zolpidem. Particularly in patients who have been on the drug for a long time or those who are on higher doses. Abnormal sleeping...

On this episode, I discuss the pharmacology of oral semaglutide. It is a GLP-1 agonist that is the first one in the class to have an oral formulation. There is a recommended dose titration with oral semaglutide that can take a month or two to get therapeutic doses. I disucss this further in this episode. The most common adverse effect of oral semaglutide is nausea. Oral semaglutide is dosed once d...

Patients with G6PD deficiency who are taking probenecid are at increased risk for hemolytic anemia. In a patient taking probenecid, they need to have adequate kidney function for the drug to work. GI upset is likely the most common adverse effect of probenecid. It can be given with food. Probenecid can raise the concentrations of many common antibiotics like penicillins and cephalosporins. Remembe...

Nicotine replacement therapy is an important tool in helping our patients quit smoking. There are lots of clinical pearls involving the pharmacology of nicotine patches and I explore them in this episode. Nicotine patches differ from the gum and other acute relief forms in that they are intended to provide a consistent level of nicotine in the body. The initial dosing of nicotine patches is depend...

Doxepin is under the class of tricyclic antidepressants. It can inhibit the reuptake of serotonin and norepinephrine. In addition to the serotonin and norepinephrine reuptake inhibition mechanism, doxepin also has antihistamine type effects. Because of the anticholinergic activity of doxepin, it is recommended to avoid this medication in the elderly, particularly at high doses. Be aware that antic...

Atomoxetine is a norepinephrine reuptake inhibitor that can be used in the management of ADHD. Atomoxetine is a non-controlled substance option for patients seeking this alternative to traditional stimulants. CYP2D6 is an important enzyme in the breakdown of atomoxetine. CYP2D6 inhibition or poor metabolizers via CYP2D6 can lead to higher concentrations of atomoxetine and put our patients at great...

Fluoxetine is an SSRI used in the management of depression, anxiety, OCD, PTSD, and other psychiatric conditions. Fluoxetine has a very long half-life which can impact clinical management. I discuss how this matters in this podcast episode. Fluoxetine inhibits CYP2D6 which can alter the concentrations of many drugs. Prodrugs like codeine and tamoxifen can have their effects reduced because of fluo...

Metoprolol is a beta-blocker commonly used in the management of hypertension, heart failure, and atrial fibrillation. There is an extended release dosage form and immediate release dosage form with metoprolol. The advantage of the extended release product is that it doesn’t require as frequent dosing. Metoprolol is selective for beta-1 receptors. It is less likely to interact with asthma med...

Mometasone is an inhaled corticosteroid and a nasal corticosteroid. The inhaled steroid is called Asmanex by brand name and the nasal version is Nasonex. Nasonex is primarily used in the management of allergic rhinitis and can help with nasal congestion type symptoms. Remember that nasal mometasone takes a little while to have its full effect. It can take up to a week or two to provide its maximum...

Methylphenidate has an FDA approved indication for ADHD. In this podcast episode, I cover the pharmacology, adverse effects, kinetics, and drug interaction. Because methylphenidate has stimulant type effects, it can raise blood pressure and heart rate. Weight, blood pressure, and pulse are important monitoring parameters in patients taking a stimulant type medication like methylphenidate. There ar...

Cilostazol has antiplatelet and vasodilatory effects. Because of this, it can manage symptoms of intermittent claudication. GI upset, headache, and edema are common adverse effects associated with the use of cilostazol. Cilostazol is recommended to be given on an empty stomach. In patients with heart failure, cilostazol use is contraindicated. CYP3A4 interactions are prevalent with cilostazol. Inh...

Metronidazole (Flagyl) is an antibiotic that is used for various infections. Metronidazole can certainly cause GI upset like most antibiotics, but uniquely may also cause a metallic taste. Metronidazole is also rarely associated with CNS changes and can induce the potential for peripheral neuropathy. Patients should avoid alcohol with the use of metronidazole and this is on account for the possibi...