Opioid (heroin) overdose is marked by a decreased respiratory drive, shallow breathing, and pin-point pupils. Treatment is with naloxone and reverses overdose quickly. Heroin overdoses can be fatal if untreated because of the respiratory depression.

This patient likely has opioid (heroin) overdose. Common signs of overdose include: altered mental states, decreased respiratory rate and effort, and pin-point pupils. Treatment includes inhalation of naltrexone to remove the opioids off their receptors in the body. Additionally, track marks are a sign that the patient injects heroin.

The first-line treatment for uncomplicated urinary tract infection with Proteus mirabilis is a 3 day course of either oral quinolone or trimethoprim/sulfamethoxazole (TMP/SMZ). 10-21 day courses are only appropriate in patients with complicated UTI or co-infections. Ampicillin and cefalexin are poor choices for initial treatment due to a 10-20% rate of resistance in Proteus species.

While all of the organisms listed are capable of causing UTI's, Staphylococcus species are all Gram-positive. Escherichia coli, while responsible for 75-95% of all UTI's, would not result in a urinary pH of 9.5. The high alkalinity of this patient's urine suggest a urea-splitting bacteria such as Proteus. 

Due to its production of urease, Proteus mirabilis infection results in alkalinization of urine (as urease hydrolyzes urea to produce ammonia). This can cause the formation of calcium, struvite, or apatite crystals in the urine, which may form renal calculi. 

P. mirabilis is not associated with increased risk for infertility, PID, or bladder cancer. 

The correct answer is "pyelonephritis." This is the correct answer because the patient's presentation with dysuria that progresses to include fever, chills, and lower back pain, is a very classic presentation of pyelonephritis. Pyelonephritis is an infection of the renal parenchyma, most commonly due to an ascending urinary tract infection. In this patient, who is a female (which places her at a greater risk for UTI's as compared to males due to females having shorter urethras than males) who initially has dysuria, this is a convincing story for a UTI. Further, the fact that the symptoms of fever, chills, and lower back pain are not present initially with the dysuria, but develop over the next day, is further evidence that pyelonephritis is the likely diagnosis. The physical exam finding of unilateral costovertebral angle tenderness also is highly suggestive of pyelonephritis. 

The other choices are incorrect. Spinal stenosis is not a common diagnosis in young, otherwise healthy patients, and would not account for dysuria and unilteral costovertebral angle tenderness. A pneumothorax would not cause dysuria and would likely present with shortness of breath. Primary syphilis and genital herpes would not account for dysuria, lower back pain, or costovertebral angle tenderness.

The correct answer is "primary syphilis." This is the correct answer as the classic presentation of primary syphilis is a painless chancre found on the base, shaft, or glans of the penis. The other choices are incorrect. A urinary tract infection would not present with a chancre, and would typically present with dysuria. Chlamydia or gonorrhea would typically present with penile discharge in males, not a painless chancre. Genital herpes would typically present with one or multiple painful ulcers on the penis, not a single painless chancre.