Real Life Pharmacology - Pharmacology Education for Health Care Professionals

Simvastatin use has declined over time due to more potent statins being available and due to numerous drug interactions. Grapefruit juice can inhibit CYP3A4 which will increase the concentrations of simvastatin. Genetic variations in SLCO1B1 can lead to patients being more susceptible to simvastatin toxicity. Simvastatin is a lipophilic statin. I discuss why this is important and how it might impa...

Citalopram is an SSRI used in the management of depression, anxiety, OCD, and PTSD. How do you manage the risk of citalopram causing QTc prolongation? I discuss it further in the podcast. Omeprazole can inhibit CYP2C19 which affects the metabolism of citalopram. I discuss the clinical impacts of this interaction in the podcast. Geriatric dosing with citalopram is recommended to be lower than tradi...

Epoetin alfa is essential exogenous erythropoetin which can stimulate the production of red blood cells. It is critical to ensure adequate iron stores when using EPO. Risks for blood clots, strokes and heart attacks are critical to recognize with the use of epoetin. Dosage adjustments with epoetin are typically made with respect to the amount of change in hemoglobin. I discuss this further in the...

Dexamethasone has numerous possible indications such as asthma, chemotherapy-induced nausea and vomiting, and pain associated with inflammation. Dexamethasone is more potent than prednisone. Approximately 0.75 mg of dexamethasone is equivalent to 5 mg of prednisone. When using dexamethasone, recall that it can raise blood sugars. Monitor this closely in patients with diabetes. A dexamethasone supp...

On this episode, I discuss sildenafil pharmacology, adverse effects, and important drug interactions. Sildenafil’s most common and concerning adverse effect is in relation to its ability to lower blood pressure. I discuss this further in the podcast. Sildenafil can cause rare visual changes that patients should be aware of and report immediately to their pharmacist or physician. The sildenaf...

On this episode, I discuss codeine pharmacology and practical clinical practice pearls. Codeine is metabolized by CYP2D6 to the active metabolite morphine. I discuss how this can be affected by genetics as well as other medications. Constipation is a problem with codeine and all opioids in general. Education and making a plan with patients to combat this side effect is important. Codeine is less p...

Dexmedetomidine is a selective alpha-2-adrenergic agonist with sedative characteristics. Dexmedetomidine is commonly used in ICU and procedural sedation, as well as postoperative pain. A few of the more serious adverse effects of dexmedetomidine to keep an eye on including bradyarrhythmias/bradycardia and hypotension. Dexmedetomidine undergoes hepatic metabolism, meaning a dose reduction may be re...

On this episode, I discuss the pharmacology of calcitonin. Calcitonin has an indication for osteoporosis as well as hypercalcemia. When considering drug interactions with calcitonin, recall that it can lower calcium levels which could have a cumulative effect when combined with loop diuretics. Calcitonin nasal spray should be stored upright and primed prior to use. I discuss important drug interac...

Rivastigmine is an acetylcholinesterase inhibitor used in the management of certain dementias. I discuss rivastigmine pharmacology on this episode. Weight loss is a potential adverse effect of rivastigmine. It is important to monitor weights. Anticholinergic medications such as diphenhydramine can blunt the effects of rivastigmine. Rarely, acetylcholinesterase inhibitors like rivastigmine can caus...

Caffeine is a commonly used supplement and is found in many food and beverages. I discuss caffeine pharmacology, adverse effects, and drug interactions. Caffeine can inhibit CYP1A2 and also be affected by CYP1A2 inhibitors. I discuss some examples in the podcast. It is critical to inquire about caffeine intake when patients are reporting insomnia. Caffeine has been associated with increases in pul...

Colestipol is a bile acid sequestrant that can be used in the management of hyperlipidemia. By binding bile acid in the gut, colestipol can lower LDL that is bound to bile acid by eliminating it through the feces. Numerous drug interactions existed as colestipol can bind many drugs. This is a downside to its use and why it isn’t a preferred hyperlipidemia agent. In patients with elevated tri...

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...