 [ Symptoms ] what is the max dosage of zyrtec  i am a 62 280 lb male can i take 20 mg total of zyrtec at once i read somewhere the max dosage is 20mg [ Disease ] your first and most important step is to get an accurate diagnosis which is based on examination findings you may need to see an orthopedist for a higher level examination if the orthopedist feels that you would need imaging studies then so be it but right now getting an mri may be premature anti inflammatory medications can definitiely help but again having a definitive diagnosis is critical so get a referral to a specialist