Hyoscyamine Pharmacology

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.

Sedation is a concern with hyoscyamine and this can be exacerbated by drugs like benzodiazepines, opioids, and older antihistamines.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Calcium Acetate Pharmacology

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 diuretic in combination with calcium acetate may increase the risk for hypercalcemia.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Nortriptyline Pharmacology

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 dementia medications.

Dry mouth, dry eyes, sedation, urinary retention, and constipation are a few of the more common adverse effects of nortriptyline.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Hydroxychloroquine Pharmacology

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 monitoring purposes are critical.

Rarely, hydroxychloroquine can be associated with blood disorders like neutropenia and thrombocytopenia. In addition, alterations in liver function have been reported.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Latanoprost Pharmacology

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 and potentially oppose the beneficial effects of latanoprost.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Terbinafine Pharmacology

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 has the potential to cause liver impairment. I discuss this further on the podcast.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Alendronate Pharmacology

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 with the use of alendronate.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Diazepam Pharmacology

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 accumulate in the geriatric patient population and cause adverse effects like sedation, confusion, and falls.

Respiratory depression, coma, and death are significantly more likely in overdose situations where opioids are used in combination with benzodiazepines like diazepam.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Dicyclomine Pharmacology

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 important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Diltiazem Pharmacology

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 differently from dihydropyridine calcium channel blockers (like amlodipine) as it works on the heart AND the vessels.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!