Serotonin Reuptake Inhibitors(SSRI) and Monamine Oxidase Inhibitors(MAOI): Major Drug Interaction That should not be left ignored

Wonderful Guest Post via Amanuel T. B.Sc., Pharm.D. – Clinical Pharmacist: View his profile on Linked In

Have a passion for medication education?  Would you like to give back to healthcare students?  Would you like to be an expert on a particular topic and increase the size of your professional network?  Please be a guest contributor and donate a medication related case that all healthcare professionals can learn from!

Thanks again to Amanuel for donating!

If you haven’t subscribed yet for future updates and access to more free clinical medication content, please Click Here to do so!

Case Study:

A 24 year old male patient with cystic fibrosis was admitted due to CF exacerbation and flare up. He’s known to have chronic sinusitis, colonized with MRSA and mucoid pseudomonas. New culture from this admission grew out MRSA and Pseudomonas.
Allergy : vancomycin (Redman’ syndrome) & Amoxicillin
Patient’s vital signs were unremarkable with a temp of 35.5c, blood pressure (sbp/dbp) of 105/57 mmhg respectively, heart rate of 89bpm and respiratory rate of 18br/min
His laboratory parameters include a serume creatinine = 0.57 mg/dl and wbc = 9.7 x10 3.
patiet’s home regimen which were documented on his chart are of multitude nature and include: Sertraline 50mg, pancrelipase , omeprazole 20mg, vitamin E and Albuterol inhaler among others.
Upon admission, patient was started on broad spectrum antibiotics which included: linezolid 600mg (vancomycin was discontinued 24hrs after initiated), colistimethate 80mg, ceftazidime 2 gram in accordance to the hospital protocol.


During verification process the pharmacist noted a major drug-drug interaction that occur between two of the patient’s regimen which could cause potentially serious harm. The drugs in question are sertraline, a serotonin reuptake inhibitor widely used in the treatment of depression, and linezolid, an antimicrobial agent used as an alternative to vancomycin to treat MRSA infection.
There’s a well-established medical data that “coadministration of linezolid (MAOI) with serotonergic agents may potentiated the risk of serotonin syndrome, a rare but serious and potentially fatal condition…” Symptomes of serotonin syndrome may include mental status changes such as irritability, altered consciousness, hallucination and coma; autonomic dysfunction such as tachycardia, hyperthermia, diaphoresis, shivering and mydriasis; and neuromuscular abnormalities such as hyperreflexia, tremor and rigidity.

The Medical Resident who initiated the order was contacted and alternatives were given to avoid the harmful effects which may ensue from such interaction without delaying therapy. One option was discontinuation of Sertraline temporarily until patient’s infection is adequately treated using appropriate clinical parameters. Initiation of another antidepressant agent from a different group would be another option to look into. Unfortunately, most antidepressants on the market. including the tricyclic antidepressants (TCAs) posses serotonergic activities to a certain degree and have been shown to interact with MAOIs significantly.
After reviewing and weighing in the pros and cons in using serotonergic agent along with a monamine oxidase inhibtor; assessing patient’s clinical condition for which he was readmitted and given that vancomycin, the one and best alternative to linezolid in treament of MRSA, could not be used due to intolerance, the discontinuation of sertraline until patient’s overall clinical conditions imporve was deemed the best option.

For updates and access to premium content, please subscribe on the right hand side of the page (or bottom for mobile users) if you haven’t already done so!  An email address is all that is necessary and we respect your email privacy.

Life Threatening Morphine Errors

This is a topic that can’t wait anymore. Math. I said it, please don’t stop reading, this may help you or someone you care about prevent a devastating medication error. While most medications errors do not impact patient health, there is a medication error I see happen that can: Errors involving concentrations of liquid dosage forms. Liquid oral morphine is the classic example of a drug that has numerous strengths and liquid concentrations. The two concentrations I see most often are the concentrated morphine at 20mg/ml and also I will occasionally see 10mg/5ml. If these two concentrations get messed up, you are looking at a 10-fold error. Take 2.5 mls of the 10mg/5ml dose, and you get a 5 mg dose. If the concentrated morphine was (in error) dispensed, administered, or written for, you are looking at a 50 mg dose! If you get easily confused with these conversions, you must ask for help to double check your work. Please remember to look and think about the concentration of a liquid you are using as I’ve seen this situation end badly before and don’t want to see it again.

For access to more great content, please subscribe at the right hand side of the page (or the bottom of the page for mobile users)!

Amlodipine Simvastatin Interaction Med List

Vesicare 19

1.  The interaction between amlodipine and simvastatin was the first thing I notice – Currently, FDA recommends a max dose of simvastatin 20 mg daily if on Norvasc – Also noted that amlodipine is listed twice which is the generic name of Norvasc.

2.  I can’t help but wonder why they are using the methotrexate injection in this case, and along with that what the indication is that it is being used for?  Also remember that Folic Acid supplementation is recommended with methotrexate which this patient is on.  I would be interested to know why they are on a daily dose of 2 mg (folic acid).

A few other points that I would look into - PRN analgesic for breakthrough pain, with Fosamax use would look into why we aren’t supplementing with vitamin D/calcium, 5 injections would maybe nice to get down to 4 if possible (6 with methotrexate weekly) - relatively low dose Lantus could maybe go to one injection depending upon history, frequency of triptan for migraine, and both gabapentin and amlodipine can contribute to edema issues and would look into Lasix timing/relationship.  Plenty of labs to be monitoring as well!

Please feel free to add anything else!

Free webinar on the 10 commandments of polypharmacy is available to subscribers – simply enter email at the upper right hand side of the page and hit submit! (For mobile users, you can find this at the bottom of the page) Thanks!

Diabetes Med List Review

Oxycodone 18

Pretty extensive med list, and I’m going to pick out three points that need to be investigated – It’s really hard to limit it to three, but that gives you all an opportunity to identify other potential problems!

1. They have orders for management of hypoglycemia here, and they are on a very steep dose of glipizide – it’s pretty obvious to me that we need to monitor blood sugars very closely!  On Actos (pioglitazone) as well which is split up into two doses.  Usually given once daily, but would need to investigate that further as well.

2. Oxybutynin patch is usually dosed twice weekly – certainly need to address this and make sure that is correct, beneficial, and tolerable for the patient.

3.  Appears to be a probable rehab patient with the Aspirin dosed twice daily for one month.  One thing I’ve come across several times is to make sure that anticoagulation/antiplatelet therapy get addressed long term versus short term.  In this case, there is no noted order to continue Aspirin for CV prophylaxis, and they are likely a candidate long term being on the statin with diabetes meds.  GI and bleeding risk history certainly needs to be assessed as well before continuing long term antiplatelet therapy.

As always – comments/suggestions are encouraged!

For strategies to help minimize polypharmacy, subscribers have unlimited and free access to a webinar of the 10 Commandments of Polypharmacy – Please sign up!  More content is in the works as well!  Simply subscribe on the upper right hand side of the page (or down at the bottom of the page for mobile users).

Respiratory Med List Review

Reminder: For strategies to help minimize polypharmacy, subscribers have unlimited and free access to a webinar of the 10 Commandments of Polypharmacy – Please sign up!  More content is in the works as well!  Simply subscribe on the right hand side of the page (or down at the bottom of the page for mobile users).  Here’s tonight’s med list!

Ativan 16


Med List Review tonight! – Where I pick out a couple of points to prioritize, and you can help by adding in other things you’d like to investigate with the patient’s medications!  I’m going to try to restrain myself tonight!

1. Pretty obvious to see from the meds that this patient has some significant respiratory issues.  Between Advair, Spiriva, Albuterol, oxygen, and (likely) oral prednisone – this patient obviously struggles in that department.   Always important to try to minimize systemic prednisone if possible, so would like to know if that’s a chronic dose or a short term burst.  If chronic prednisone, osteoporosis amongst other things should be assessed/treated as appropriate (i.e. Vitamin D, Bisphosphonate).

2. Decent doses of Lasix/potassium, so I’d make sure the electrolytes/kidney function looks ok.

Plenty more to address – Thanks in advance for your ideas/comments!


Clinical Medicaton Review 2

Clinical Med Review

By popular demand, another med review tonight, where I pick out a couple of points to investigate and I let you all have your crack at the list!

Both Prilosec and Zantac (ranitidine) being utilized here, would like to look into the GI history and assess if both are necessary.  By the other meds, they are not very high risk for GI bleed as only on low dose aspirin, but again need to investigate history further.

Plenty of BP meds and would suspect edema or CHF history.  I would like to dig into Lasix/Maxzide history to assess if both are necessary.  Remember that Maxzide is a combo of diuretics and does work differently from Lasix, but when trying to tackle polypharmacy, this might be a place to look into further.  Also remember that Maxzide contains triamterene a potassium sparing diuretic which might be helping stabilizing potassium levels as both the Lasix and hydrochlorothiazide (in Maxzide) can bring potassium down.

Ultram (tramadol) and Percocet needs some investigating as well!

Have at it all!

If you enjoyed this post, please check out the 10 Commandments of Polypharmacy Webinar, full of clinical pearls and strategies to try to minimize polypharmacy and improve patient safety – simply subscribing on the right hand side of the page will get you free access with no strings attached!

Meducation Nation

The State of the Union

It all started with educational posts on Facebook and has been a wild ride since then, and I’ve certainly invested way too much time to turn back now!  It’s been 1 year since the initiation of meded101, and approximately 6 months since the initiation of this site and I’m extremely optimistic about the future of medication education.  I can’t thank you all enough for the support!

Here’s a breakdown of the interest in medication education we’ve generated with meded101:

On the Facebook page, our contributors and myself have generated a reach of over 80,000 with over 600 likes

On Twitter @mededucation101 – The tweets have reached over 70,000 accounts and have made over 120,000 impressions in the last week alone!  Currently there are over 2,300 followers of the @mededucation101 Account!

On the website , there’ve been nearly 25,000 page views in over 100+ countries since initiation of the site!

A few goals I’m going to throw down for the coming year -

1. Additional 50,000 page views to the website

2. 2,000 likes on Facebook

3. 5,000 followers on Twitter

4. Creating innovative ways to educate including unique recorded webinars, live webinars, and premium content!

5. Having more unique posts from guest contributors who are experts in their field!

Thank you all so much, and a special thanks to the early adopters of meded101 – You know who you are!


Clinical Medication Review

Med List 1

med list part two

A significant clinical medication review for everyone today, where I pick out a couple areas of concern to me and you can help do the rest by adding any comments/thoughts/questions below!  There’s plenty to pick on in this one, so I may need a little help to cover everything! – Also reminder that new subscribers can get free unlimited access to my 20 minute webinar on the 10 Commandments of Polypharmacy – just look on the right side of the page to subscribe.  As always with these med list reviews, your priorities are going to depend upon what is going on with your patient, so this is really more of an educational exercise to help get your mind right in trying to identify medication related problems!

The first concern that jumped out at me that I’d look to investigate is the Ritalin indication.  Also, the fact that Ritalin is being used in combination with Klonopin and potentially the  Remeron at night, both of which can be sedating – so we are using a combination meds that can ramp you up and potentially slow you down.  Also looks like plenty of cardiac issues by the meds which Ritalin needs to be monitored closely for.

Always important when you get someone on this many meds not to lose sight of the fact that they are on Coumadin (warfarin) which as I’ve mentioned before can have a ton of drug interactions – so we need to be extra careful about medication changes – I’ve posted a few cases on Coumadin before if you’d like to check them out, search Coumadin on the site!

There are plenty of labs we need to monitor…Synthroid, Lisinopril, Digoxin, Coumadin, Glyburide, Lasix etc.

I can’t resist…one more thing – I’d like to know why they are on Duonebs TID without any controller type medication - suspect maybe a recent acute respiratory issue in which maybe long term scheduled nebs would not be necessary, but certainly needs to be investigated further.

Please feel free to comment!

If you enjoyed this post, please check out the 10 Commandments of Polypharmacy and the Worst Case of Polypharmacy I’ve ever seen!


Anticholinergics can Worsen BPH

85 year old male with a recent operation for a knee replacement was discharged on hydrocodone/APAP 5/325 1-2 every four hours as needed as well as Vistaril (hydroxyzine) 25-50 mg every six hours as needed for pain management. Within a couple days of significant prn use for the pain, the patient was understandably dealing with some constipation issues that were easily managed with Senna-S 2 tablets daily. After about 5-7 days, this patient began to have worsening urinary retention and was placed on Flomax (tamsulosin) 0.4 mg daily to help treat the retention. The following day, the retention was getting even worse and a Foley catheter had to be placed. This gentleman did have a history of BPH and retention, and here’s a perfect demonstration why anticholinergics (Vistaril) in the elderly should be avoided or at least be minimized. This patient was using the 50 mg dose as often as he could which was certainly worsening the urinary retention. Remember, can’t spit, see, PEE, or poop – are a few of the anticholinergic effects that can be pretty nasty in the elderly!

Serotonin Syndrome or Something Else?

88 y/o female who’s had some difficulty with pain management.  She was on scheduled Tylenol (acetaminophen) 1,000 mg twice daily as well as Ultram (tramadol) 50 mg every 6 hours as needed.  She had brought up the complaint about her osteoarthritis to her physician.  She was prescribed Ultram 100 mg four times daily scheduled.  When I had spoke with the caregivers, they had been doing some research and were significantly concerned about serotonin syndrome due to increased confusion general declining condition and worsening mental status.  This patient was on an SSRI – Celexa (citalopram) 20 mg daily as well.  However, there were no other symptoms of serotonin syndrome (like tachycardia, elevated temp etc.) besides the change in cognition.  Serotonin syndrome is very serious, but the oversight in this case was that the patient was very reluctant to take the as needed Ultram and upon discussion with caregivers, she was only taking the PRN Ultram one or two times daily on average.  The increase from 50-100 mg per day to 400 mg per day was simply too aggressive in this case.  Another key point is that the maximum recommended daily dose of Ultram is 300 mg for the elderly.  Adverse effects improved with a reduction in the Ultram to 50 mg three times daily.

Interprofessional Medication Education