What is a critical instruction for taking Alkeran (melphalan)?

Taking Alkeran (melphalan) on an empty stomach is a critical instruction because it enhances the drug's absorption and effectiveness. The presence of food in the gastrointestinal tract can interfere with the medication's ability to be properly absorbed into the bloodstream, reducing its therapeutic effects. Therefore, for optimal results, patients are advised to take melphalan as directed, without food.

The other options, while they may seem reasonable at a glance, do not hold true according to the standard guidelines for this medication. Alkeran does not need refrigeration, nor is it specifically indicated to be taken only once a week; the dosing schedule can vary based on the patient's condition and treatment plan. Also, it is not recommended to take the medication with food, as mentioned earlier. This makes the instruction to take it on an empty stomach the most critical aspect of its administration.