CYP Substrates
Drugs that increase a specific measurable lab
If we order these labs, what are we looking at or trying to figure out?
Drugs that decrease a specific measurable lab
If I am looking at these labs, what am I trying to figure out
100

methadone, statins, amiodarone, diltiazem, NNRTIs

What are 3A4 substrates

100

ACE and ARBs, Bactrim, aldosterone receptor antagonists, canagliflozin all cause an increase in ____

Potassium 

100

amylase and lipase

Pancreatic function 

100

Lactulose decreases ____

ammonia

100

TSH, T4, FT4

Thyroid function 

200

theophylline, R-warfarin, olanzapine

What are 1A2 substrates

200

metformin (especially in renal disease or heart failure), NRTs, alcohol use, cyanide cause an increase in ______

What is lactic acid (lactate)

200

PT, INR, aPTT

Anticoagulation 

200

Clozapine has a boxed warning regarding this and previously, it was the reason for the REMS (which is no longer a REMS)

WBC--neutropenia 

200

A1C

Diabetes, average blood glucose

300

codeine, tramadol, meperidine, tamoxifen

What are 2D6 substrates

300

Risperidone, paliperidone, and haloperidol all increase this (hint: it can lead to gynecomastia)

What is prolactin?

300

C-reactive protein, rheumatoid factor, erythrocyte rate

Inflammation or autoimmune disease

300

PPIs, metformin, colchicine can all decrease this vitamin 

B12

300

TC, HDL, LDL, TG

LIPD panel used to assess cholesterol types and determine cardio risk

400

S-warfarin 

What are 2C9 substrate

400

Diuretics, niacin, low doses of aspirin, pyrazinamide, and cyclosporine all increase this 

What is uric acid?

400

pH, pCO2, pO2, HCO3, O2 sat

Acid-Base

400

Phenytoin, phenobarbital, primidone, methotrexate can all cause a decrease in this ______

Folic acid 

400

MCV and MCH

Anemia work up  

Decrease in MCV --> microcytic anemia due to iron deficiency 

Increase in MCV ---> macrocytic anemia due to B12 or folate deficiency

500

clopidogrel 

What is 2C19 substrate

500

Valproic acid and topiramate can increase this lab which is often measured in suspected hepatic encephalopathy

Ammonia

500

CK (or CPK), Troponin, B-Type Natriuretic peptide

Cardiovascular

500

systemic steroids decrease this type of blood cell (we also see this happen with HIV and bone marrow suppression)

Lymphocytes

500

Anion Gap

Metabolic acidosis

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