The patient is diagnosed with a severe urinary tract infection (pyelonephritis), and you decide to prescribe him sulfamethoxazole/trimethoprim (SMX/TMP) 800/160mg one tab PO Q12h x14 days Over the next couple of weeks, the symptoms associated with his UTI diminish, and his mental status improves. However, Ms. Webb brings him back to your clinic with symptoms, which scare her yet again, and she explains that she thinks he may have a relapse of his UTI. These symptoms include a high fever (103.6°F) and tachypnea, and upon pulmonary examination at your clinic, you hear crackles, and find classic findings of lung consolidation. 

• What laboratory tests should you order, and what is your primary diagnosis at this point and subsequent steps in his treatment and management? 
• Once explained, please indicate and describe your chosen pharmacological treatment with inclusion of dose and mechanism of action of your chosen prescription.