Tizanidine Pharmacology

Tizanidine is primarily broken down by CYP1A2. Ciprofloxacin can inhibit CYP1A2 and cause higher tizanidine concentrations.

Tizanidine has a similar classification as clonidine. Pay attention to adverse effects like hypotension and bradycardia.

When patients taking routine tizanidine stop taking it, there is potential for a discontinuation syndrome that may lead to rebound hypertension.

Dry mouth and CNS depression are common adverse effects of tizanidine.

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.

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Codeine Pharmacology

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 potent than other opioids such as fentanyl, hydromorphone, and hydrocodone.

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!

Morphine Pharmacology

Morphine has opioid agonist activity that can cause respiratory depression and death in overdose.

Morphine-6-glucuronide is the metabolite that can accumulate and cause CNS toxicity in renal failure.

Be aware of CNS depressants that may enhance the effect of morphine and other opioids. Some examples of CNS depressants include gabapentin, benzodiazepines, older antihistamine, skeletal muscle relaxants, and pregabalin.

Opioid withdrawal is a significant concern when patients have their morphine or another opioid abruptly stopped. Some signs of withdrawal include agitation, mood swings, anxiety, sweating, GI upset, pain, and insomnia.

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

Celecoxib Pharmacology

Celecoxib is easy to remember as its mechanism of action is “COX”-2 Inhibition. This can result in result in reduced prostaglandin formation and help with pain and inflammation.

Kidney function is important to monitor in our patient on celecoxib. It is especially important in patients taking ACE inhibitors, ARBs, and/or diuretics.

While GI bleed may be less likely with celecoxib compared to traditional NSAIDs like indomethacin and ibuprofen, it still needs to be monitored for.

Digoxin concentrations may be increased with the use of celecoxib.

Celecoxib is generally dosed twice per day as the half-life of the drug is in the ballpark of 10-12 hours.

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

Methotrexate Pharmacology

On this episode of the Real Life Pharmacology Podcast, I cover the pharmacology of methotrexate.

Methotrexate has a few different indications. It can be used for treatment of cancer. These doses are typically going to be much higher than standard low doses for other conditions.

Lower dose methotrexate is often used for autoimmune type conditions like rheumatoid arthritis and psoriasis.

Folic acid should be supplemented with use of methotrexate to help reduce the risk of adverse effects.

Liver toxicity and immune system suppression are two important factors to monitor in a patient taking chronic methotrexate.

I also talk about important cumulative drug interactions with methotrexate such as immunosuppressives and other agents that may impact liver function.

Be sure to listen to the end as I talk about the potential impact of methotrexate on some vaccines!

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

Cyclobenzaprine Pharmacology

On this episode, I discuss cyclobenzaprine pharmacology. Cyclobenzaprine is an older skeletal muscle relaxant.

Cyclobenzaprine can have a significant number of anticholinergic side effects.

The anticholinergic side effects of cyclobenzaprine can include sedation, dry eyes, dry mouth, urinary retention, and confusion.

Cyclobenzaprine is not well tolerated in the elderly and cause more problems in that patient population.

Cyclobenzaprine has a similar structure to the Tricyclic antidepressants.

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

Fentanyl Pharmacology

On this episode, I discuss fentanyl pharmacology.

I address important considerations that you must remember with fentanyl patches.

Those considerations include how pharmacokinetics can impact our patients.

I also break down common side effects of opioids as well as potential common drug interactions.

Drug diversion and illicit use is an important consideration when using fentanyl.  I also touch on this topic.

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Allopurinol Pharmacology

I break down the mechanism of action, side effects, and important drug interactions you need to know. I give you a sense of what things you might actually encounter in practice when working with patients who take allopurinol.

Allopurinol is a top 200 drug. Remember to subscribe to the website reallifepharmacology.com for the Free 31 page PDF where I give you three highly testable pearls on the top 200 drugs.

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I hope you enjoy this episode the pharmacology of allopurinol!

Hydrocodone and Acetaminophen Pharmacology RLP Episode 029

On this episode, I discuss the pharmacology of hydrocodone.  We also cover adverse effects, clinical use, and important genetic and drug interactions.  Enjoy the show and don’t forget to subscribe to the podcast and receive a couple of free gifts!