JB is a 28 year old non-pregnant female patient that comes to your community pharmacy to pick up her medications. Among her regular refills, she has one new medication that her rheumatologist recently prescribed. The new prescription is for methotrexate.

PMH:

Rheumatoid arthritis

Hypertension

Obesity

GERD

Anxiety

Current medication list:

Lisinopril 10 mg PO QD

Semaglutide 1 mg SQ weekly

Amlodipine 5 mg PO QD

Famotidine 20mg PO BID

Ativan 0.5 mg PO BID prn

Motrin 600 mg PO TID

Which of the following is true regarding methotrexate and this patient case? Select all that apply. 

A. For the treatment of rheumatoid arthritis methotrexate should be taken once daily

B. There is a potentially significant drug interaction with methotrexate and famotidine

C. JB should have her liver enzymes monitored while taking methotrexate

D. Methotrexate would be contraindicated in JB if she becomes pregnant

E. Methotrexate may increase the risk of hyperkalemia with JB's lisinopril

Rheumatoid arthritis (RA)  is a chronic disease that affects 1% of the US population. RA is three times more common in women compared to men. RA occurs when the person’s immune system is unable to differentiate native from non-native tissues, and the immune system attacks synovial and other connective tissues causing cellular damage and inflammation primarily in joints.  Common clinical presentations include: chronic pain, stiffness of joints, and tenderness, warmth, and/or swelling of joints. Methotrexate is one of the many recommended treatment options for RA. Methotrexate belongs to a class of medications called Disease-Modifying Antirheumatic Drugs (DMARDs). While methotrexate can be effective in the treatment of RA, its use can be limited due to its side effect profile and potential to interact with other medications. Biologics, such as adalimumab, are often added to methotrexate when patient's have an incomplete response. 

Answer A is incorrect: Methotrexate should be dosed once weekly in the management of RA. This is a common misfill that happens in clinical practice and should be avoided to ensure patients do not get toxicity which can manifest in a number of ways including aplastic anemia. 

Answer B is incorrect: There are no interactions with histamine receptor-2 antagonists and methotrexate. Proton pump inhibitors when given with higher doses of MTX used in chemotherapy can potentially cause increased concentrations of MTX.

Answer C is correct: Methotrexate can cause increased liver enzymes which can ultimately lead to hepatotoxicity through fibrosis or cirrhosis. Monitoring liver enzymes regularly can help prevent the progression of hepatotoxicity.

Answer D is correct: Methotrexate is contraindicated in pregnancy. It has been shown to cross the placenta and cause fetal harm including fetal death. Its use should be avoided in pregnant patients. In some circumstances, methotrexate is used to terminate ectopic pregnancies. 

Answer E is incorrect: There is no additive risk of hyperkalemia with these two agents. 

Brand/Generics Covered:

Methotrexate (Trexall, Rheumatrex), Lisinopril (Prinivil, Zestril), Semaglutide (Ozempic, Wegovy), Amlodipine (Norvasc), Lansoprazole (Prevacid), Lorazepam (Ativan), Ibuprofen (Motrin)

Naplex Competencies Covered:

Area 1 – Obtain, Interpret, or Assess Data, Medical, or Patient Information

• 2 – From patients: treatment adherence, or medication-taking behavior; chief complaint, medication history, medical history, family history, social history, lifestyle habits, socioeconomic background
• 4 – From medical records: treatment adherence, or medication-taking behavior; chief complaint, medication history, medical history, family history, social history, lifestyle habits, socioeconomic background
• 5 – Signs or symptoms of medical conditions, healthy physiology, etiology of diseases, or pathophysiology

Area 2 – Identify Drug Characteristics

• 1 – Pharmacology, mechanism of action, or therapeutic class
• 2 – Commercial availability; prescription or non-prescription status; brand, generic, or biosimilar names; physical descriptions; or how supplied
• 3 – Boxed warnings or REMS

Area 3 – Develop or Manage Treatment Plans

• 2 – Therapeutic goals or outcomes and clinical endpoints
• 3 – Medication reconciliation; indication or therapeutic uses; lack of indication; inappropriate indication; duplication of therapy; omissions
• 4 – Drug dosing or dosing adjustments; duration of therapy
• 6 – Drug contraindications, allergies, or precautions
• 8 – Drug interactions