BREAK THROUGH

This section consists of a few pharmacology cases and their respective treatment
Case 1:
A 22 year old male complains of a new lesion on his penis. On examination, you find a single painless ulceration with a firm border. The patient reports that the penile ulcer has been there for over a week. Upon further questioning, you discover that he has been having unprotected sexual contact with several individuals over the last 3 months. Physical exam is also remarkable for enlargement of lymph nodes in the groin, axillary, and supraclavicular regions. Suspecting a specific sexually transmitted disease, you send him to the laboratory for RPR and VDRL test. When he returns from the laboratory, you tell him that you will empirically treat him with a shot and you warn him that rare side effects of this medication include a hemolytic anaemia.






Ans: PENICILLIN


Similar drugs: Penicillin G(i.v), penicillin V(oral)

Mechanism of Action: Bacterial cell walls are composed of a complex configuration of cross linked peptidoglycans. Formation of the peptidoglycan walls are mediated via penicillin-binding proteins(PBPS). Penicillin acts to bind PBPS, thereby blocking peptidoglycan cross-linking and thus inhibiting bacterial cell wall synthesis.

Clinical Uses: Treatment of infections caused by gram positive organisms(strptococci, pneumococci), gram negative cocci(meningococci), enterococci and spirochetes.


Side Effects: Allergic reaction; drug induced Coombs' positive hemolytic anemia.






Case 2:
A 37 year old woman presents to your ophthalmology office for a routine eye examination. In preparation for her retinal exam, you decide to dilate the patient's pupils with a medicated ophthalmic solution. The patient is curious, and she asks you how this ophthalmic solution works. You explain to her that the medication will act to constrict her pupillaary dilator muscle, thereby producing pupillary dilation. You also tell her that this is the same compound that is used to treat nasal decongestion.




Ans: PHENYLEPHRINE

Mechanism of Action: Phenlyephrine is an α1 agonist, thereby leading to systemic vasoconstriction and pupil dilation. When applied topically to the nasal mucosa, it induces vasoconstriction, thereby leading to a decrease in mucosal secretions.

Clinical features: Used to treat nasal decongestion.
Used as an ophthalmic solution to produce mydriasis for retinal examination. Also used in past to treat episodes of supraventricular tachycardia and raise both systolic and diastolic blood pressure.

Side effects: Cardiac arrhythmias; headache.


Case 3:
A 69-year old woman presents to your primary care office, complaining of a 2-week history of back pain. She admits that the pain began after she had been lifting some heavy boxes while cleaning out her husband's study. She denies any neurological symptoms. On physical exam, she has no pain with the straight-leg maneuver, thereby suggesting that she has not herniated her disk: however she does have point tenderness around the T12-L1 region. You send her for imaging studies, which reveal a vertebral compression fracture at L1. A bone scan reveals the presence of significant osteoporosis. You decide to treat her osteoporosis with a medication that acts by decreasing osteoclastic bone resorption.



Ans: ALENDRONATE


Similar Drugs: Other biphosphonates include etidronate, pamidronate, and risedronate.

Mechanism of Action: This class of drugs acts to decrease osteoclastic bone resorption by inhibiting osteoclastic activity and increasing osteoclastic cellular death.

Clinical Uses: Treatment of osteoporosis, Paget's disease of the bone, and hypercalcemia associated with malignancies.

Side Effects: GI upset.