The teaching plan for the use of a dry powder inhaler for the treatment of asthma should include the warning to rinse the mouth after inhaling the powder.
What does this prevent?

Choice A rationale

There is no specific scientific rationale requiring extra vitamin C supplementation while on isoniazid. Isoniazid can cause pyridoxine (vitamin B6) deficiency, which leads to peripheral neuropathy, due to its chemical structure interfering with pyridoxal phosphate metabolism. Therefore, vitamin B6 supplementation is routinely prescribed to prevent this adverse effect, rather than vitamin C, which is not directly involved in this metabolic pathway.

Choice B rationale

Taking isoniazid with milk or juice is generally discouraged as it can interfere with drug absorption. Isoniazid absorption is optimized in an acidic environment and can be reduced by food, particularly dairy products, which can chelate the drug or alter gastric pH. Therefore, consuming it with milk or juice might decrease its bioavailability, leading to sub-therapeutic drug levels and potentially compromising treatment efficacy against Mycobacterium tuberculosis.

Choice C rationale

Isoniazid absorption is best on an empty stomach because food, especially high-fat meals, can significantly decrease its bioavailability. The presence of food in the stomach can delay gastric emptying and interfere with the dissolution and absorption of the drug from the gastrointestinal tract. Optimal absorption ensures that therapeutic drug concentrations are achieved in the bloodstream, which is crucial for effectively inhibiting bacterial cell wall synthesis in Mycobacterium tuberculosis.

Choice D rationale

Isoniazid is not known to cause permanent staining of contact lenses. This side effect is associated with rifampin, another antituberculosis drug, which can cause reddish-orange discoloration of body fluids, including tears, urine, and sweat, due to its chromophore properties and excretion pathways. Isoniazid's mechanism of action and metabolic breakdown do not produce colored metabolites that would result in such staining.

Choice A rationale

Instructing hand washing is a general infection control measure, but it is not the most critical first action for a client with *Burkholderia cepacia*, especially in a pulmonary unit. *Burkholderia cepacia* poses a significant cross-infection risk, particularly for clients with cystic fibrosis, due to its transmissibility and potential for severe respiratory infections.

Choice B rationale

*Burkholderia cepacia* requires Contact Precautions, not Droplet Precautions. Droplet precautions are for larger respiratory droplets, while *Burkholderia cepacia* transmission is primarily through direct or indirect contact. Incorrect isolation precautions could compromise infection control and put other vulnerable clients at risk.

Choice C rationale

*Burkholderia cepacia* is highly transmissible among individuals with cystic fibrosis and can cause severe, progressive lung disease, known as "cepacia syndrome.”. Isolating the client from others with cystic fibrosis immediately upon admission is paramount to prevent cross-contamination and protect other vulnerable individuals on the unit.

Choice D rationale

While obtaining cultures is important for confirming the diagnosis and guiding treatment, the immediate priority upon admission is to prevent transmission to other susceptible clients, especially those with cystic fibrosis. Implementing isolation measures takes precedence over diagnostic testing in this specific scenario due to the high risk of cross-infection.