LN is 84 YOM who is in hospital for a back surgery. His height is 5 feet and 4 inches, weight 85 kg and NKDA.
His past medical history includes hypertension, diabetes mellitus, major depression, hypothyroidism and chronic back pain. Post-op day 1, LN's medication includes Dexamethasone 8mg iv q6h with taper dosing, Ondansetron 4mg iv q6h prn for N/V, Levothyroxine 0.075mg po daily, Lisinopril 10mg po daily, Citalopram
20mg po daily, Docusate sodium / Senna 1 tab po twice a day, Bisacodyl 10mg suppository daily prn for constipation, Famotidine 20mg iv q12hr, Metoclopramide 10mg iv q6h, Metformin 500mg po bid, D51/2NS with
20K at 125mls/hour and Hydromorphone PCA at 0.2mg/hour of basal rate, demand dose 0.1mg. lock-out every
6min, one hour limit 2.2mg/hour. Pertinent morning labs includes serum creatinine 1.4mg/dl, Mg 1.5mg/dl, K
5.0mmol/L, Na 135mmol/L.
What is the reason for holding metformin in patients with reduced renal function?

All of the following may increase triglycerides except:

JT is a 58-year-old women who is on vancomycin empirically for pyomyositis confirmed by MRI. Surgical debridement has successfully removed infected tissue and pus. C&S of the infected tissue comes back MSSA sensitive to everything on the panel. JT is allergic to PCN (rash), she has had cephalosporin for her UTI in the past with no problem.
What would be the most appropriate antibiotics to switch to while JT is still in the hospital?

An order is received to start Milrinone at 0.75mcg/kg/min, Milrinone comes as 20mg/100ml D5W. What is the infusion rate in mL/hr? Patient weighs 115kg.

An 18-year-old female is referred to a dermatologist for treatment of severe acne vulgaris. The dermatologist wants to start her on tetracycline.
What test should the patient have prior to starting treatment?