On this episode, I discuss tolterodine pharmacology, adverse effects, and drug interactions.
Tolterodine (Detrol) is an anticholinergic medication used to manage the symptoms of overactive bladder.
Tolterodine’s anticholinergic activity can lead to a significant number of adverse effects like dry mouth, dry eyes, constipation, and urinary retention.
Elderly patients may be at greater risk for anticholinergic adverse effects from tolterodine compared to younger patients.
Tolterodine can have additive effects from other anticholinergics like diphenhydramine or TCAs which enhance its potential for side effects.
On this episode of the podcast, I discuss my approach and strategies to handle grapefruit juice interactions.
Grapefruit juice causes drug interactions by inhibiting the CYP enzyme system. More specifically, it inhibits CYP3A4 which is responsible for the breakdown of many medications.
Quantity is always an important consideration when assessing grapefruit juice interactions. The more that is taken, typically, the more drug concentrations will be affected.
It is important to assess the use of grapefruit juice when your patient has a history of cardiovascular disease, cardiac conditions, pain, mental health disease, or gout as some medications used to treat these diseases can interact with grapefruit juice.
If you are looking for more content on drug food interactions, be sure to check out my book in the links below.
On this episode, I discuss atorvastatin pharmacology, adverse effects, monitoring parameters, and drug interactions.
Atorvastatin (Lipitor) is an HMG-CoA reductase inhibitor, the rate-limiting step in the production of cholesterol. It is used to prevent atherosclerotic cardiovascular diseases by decreasing cholesterol.
Atorvastatin is more lipophilic in comparison to other statins such as rosuvastatin. If a patient does not tolerate a statin, switching from a lipophilic to a hydrophilic or vice versa may decrease the chances of those side effects reoccurring.
It can be a high-intensity statin depending on the dose. 10-20mg is considered moderate and 40-80mg is classified as high intensity. Not all statins can reach high-intensity doses, which is why atorvastatin is so commonly used.
The FDA as of July 2021, has requested to remove the contraindication of pregnancy from the prescribing information. Here’s more information on that specific change and why it was requested. I’d encourage you to read it.
Atorvastatin is commonly found to have adherence issues so it should be taken whenever it is going to be best remembered by the patient.
Common adverse effects include myopathy, muscle pain, and soreness. Many elderly patients can be overlooked when they experience aches and pains, so it is important to take their medications into consideration. There are rare risks of liver injury and rhabdomyolysis. CPK and LFTs do not need to be regularly monitored if no symptoms are present.
Remind patients that their cholesterol will not be lowered right away. They will usually have their levels rechecked in 3-6 months.
Drugs that increase rhabdomyolysis risk when used concurrently include fibrates, red yeast rice, niacin, daptomycin. Monitor these patients closely for symptoms of muscle pain. Can also monitor CPK and decrease the dose of the statin in these patients. 3A4 interactions can increase the concentration of statins. These include clarithromycin, grapefruit juice, amiodarone, amantadine, and verapamil. 3A4 inducers can decrease the concentration of statins. These include St. John’s Wort and carbamazepine.
