Module 13

Diagnostic Considerations

  • Symptoms Review
      - UTI symptoms have subsided, but flu-like symptoms have emerged.
      - Consideration of Stevens-Johnson Syndrome (SJS) versus allergic dermatitis.

Allergic Dermatitis vs. Stevens-Johnson Syndrome (SJS)

  • Allergic Dermatitis
      - Typically manifests as hives and remains localized.
      - Patient usually experiences itchiness.
      - If caused by a drug, the drug should generally be discontinued, although mild cases may allow for monitoring.

  • Stevens-Johnson Syndrome (SJS)
      - Characterized by systemic, diffuse, and painful rash.
      - If untreated, can progress to a state similar to total body surface area burn.
      - Patient requires intensive care treatment including fluids and steroids for management.

Mycobacterial Infections

  • Introduction to Mycobacteria
      - Term derives from "myco" meaning fungus, but refers to a group of bacteria, particularly Mycobacterium tuberculosis (TB).
      - TB resembles fungi in structure, specifically having a mycolic acid-rich, waxy cell wall that makes it resistant to antibiotics.

  • Pathophysiology of TB
      - Mycobacteria can live inside human cells, replicating within them.
      - Pulmonary TB commonly replicates in lung cells and exhibits high mutation rates, thus necessitating multi-drug treatment for resistance prevention.

  • Phases of TB
      - TB can exist in both active and latent forms.
      - Latent TB can remain dormant for years before activating into a more severe infection.

Treatment of Tuberculosis (TB)

  • Key Therapy Acronym: RIPE
      - Rifampin
      - Isoniazid
      - Pyrazinamide
      - Ethambutol
      - These agents are selected to target active TB, while Isoniazid can sometimes be used for latent TB.

  • Adverse Effects
      - All agents are associated with hepatotoxicity, posing a significant risk of liver damage.
      - Peripheral neuropathy is a concern, particularly with Isoniazid, due to its interference with vitamin B6 (pyridoxine) levels.
      - Warning: Isoniazid exhibits monoamine oxidase inhibitor-like effects. Avoid food rich in tyramine to prevent hypertensive crisis.

  • Monitoring
      - Routine liver function tests (LFTs) must be conducted, especially for those with pre-existing liver conditions, older adults, diabetics, and individuals with a history of alcohol use disorders.

Directly Observed Therapy (DOT)

  • DOT is a strategy where healthcare workers directly observe patients taking their antibiotics to ensure adherence.

  • Essential for the management of TB to prevent the spread within the community.

Rifampin

  • Spectrum of Activity
      - Broad-spectrum antibiotic used in conjunction with others to avoid the development of resistance.

  • Adverse Effects
      - Causes urine discoloration (orange-red).
      - Gastrointestinal upset and risk of colitis are notable adverse effects.

  • Caution in Special Populations
      - Caution is advised in patients with liver disease, during pregnancy, and with concurrent use of certain medications like Warfarin.

Protozoal Infections

  • General Overview
      - Protozoa often resemble small animals; many infections are contracted from animals or contaminated water sources.
      - Common examples include Giardia, often acquired from water contaminated with animal waste.

  • Metronidazole
      - Utilized as an antibiotic for anaerobic bacteria (e.g., C. diff) as well as for treating protozoal infections.
      - Commonly recognized by the brand name Flagyl.
      - Adverse Effects: GI discomfort, metallic taste, darkened urine, and contraindicated in the first trimester of pregnancy.

  • Alcohol Interaction
      - Severe reactions with alcohol consumption while on metronidazole can occur, leading to vomiting and flu-like symptoms.

Fungal Infections

  • Understanding Fungal Infections
      - Fungal cells have a cholesterol-like component (ergosterol) in their membranes, making them difficult to treat without affecting human cells.

  • Amphotericin B
      - Administered via IV for severe systemic fungal infections such as candidiasis and aspergillosis.
      - Risk: Nephrotoxicity and infusion reactions; infusions require careful monitoring and should be administered slowly (over 4-6 hours).

  • Nystatin
      - Specifically used for topical candidiasis, not typically reserved for systemic treatments.

  • Azoles
      - Includes ketoconazole; primarily used for superficial fungal infections, but can be administered IV for severe cases.
      - Adverse Effects: Liver toxicity and potential endocrine effects, particularly reductions in testosterone leading to gynecomastia.

  • Monitoring
      - Regular assessments of liver function tests (LFTs) and watching for drug interactions.

Conclusion

  • Adherence to treatment regimens, patient education on side effects, and the importance of monitoring therapies are crucial for effective management of mycobacterial and fungal infections.

  • Emphasis on preparing for the upcoming ATI and final examinations with consistent study and practice is encouraged.