Medication information

Lasix Special 500mg tablet

This medication is a diuretic (water pill). Typically, it is used to lower blood pressure or for swelling caused by fluid retention. It may also have other uses. Its effects can be felt within 1 hour.


This medication is typically used only once a day. However, your pharmacist may have suggested a different schedule that is more appropriate for you. Important: Follow the instructions on the label. Do not use more of this product, or more often, than prescribed.

It must be used regularly and continuously to maintain its beneficial effects. Be sure to keep an adequate supply on hand. This medication may irritate the stomach, and should be taken with food. It is best to avoid coffee, spicy food or alcohol.

Consuming alcohol may modify the effect of this product. Limit alcohol consumption during treatment.

Side effects

In addition to its desired action, this medication may cause some side effects, notably:

  • it may decrease your appetite;
  • it may cause headaches;
  • it may cause diarrhea;
  • it may make your skin more sensitive to UV rays (e.g., sunlight, tanning lamps) - avoid exposure to UV rays as much as possible and protect yourself when out in the sun;
  • it may cause blurred vision;
  • it may lower your blood pressure, which could cause weakness and/or dizziness - use caution when getting up from a lying or sitting position and when driving.

Each person may react differently to a treatment. If you think this medication may be causing side effects (including those described here, or others), talk to your health care professional. He or she can help you to determine whether or not the medication is the source of the problem.


As with most medications, this product should be stored at room temperature. Store it in a secure location where it will not be exposed to excessive heat, moisture or direct sunlight. Make sure that any leftover portion is disposed of safely.

When using this product, even for a short period, you will develop an increased need for certain nutrients. Fortunately, you can easily increase your intake of these nutrients through your diet. The following table shows the nutrients that are mostly affected by your treatment, along with foods that are good sources of these nutrients. For the duration of your treatment, try to eat these foods more often to avoid a deficiency of these nutrients.

NutrientsSuggested foods
magnesiumwhole-grain cereals, broccoli, spinach, corn, avocado, dairy products, seafood, tofu, legumes, and nuts
potassiumvegetables and fruits and their juice (e.g., asparagus, artichokes, eggplant, beets, broccoli, carrots, celery, mushrooms, Brussels sprouts, cauliflower, cooked pumpkin, potatoes, spinach, parsnips, squash, sweet potatoes, green peas, rutabaga, tomatoes, apricots, avocado, bananas, mangoes, papaya, nectarines, kiwi, prunes, melon, cantaloupe), dried fruit, milk, yogurt, nuts, legumes, meat, poultry, fish and whole-grain cereal products

Additional Information

This medication may interact with other medications or supplements, sometimes significantly. Many interactions, however, may be dealt with by a dosage adjustment or a change in medication schedule. Check with your pharmacist before using this medication in combination with any other medications (including non-prescription products), vitamins or natural products.

General notes

When meeting with any health professional, it is important for you to share the following information:

  • Your medical history and allergies (medication, food, or other);
  • If you're pregnant or want to become pregnant, or if you're breastfeeding;
  • If you use tobacco or cannabis or its derivatives, or if you use recreational drugs;
  • The names of all the medications you take, whether you take them regularly or once in a while, including over-the-counter medications, vitamins, and natural health products.

It is also strongly recommended that you keep an up-to-date list of all the medications you take and carry it with you at all times. This could be useful if you have to see a health professional or need emergency care.

Keep all your medications out of the reach of children and pets and return any unused or expired medications to the pharmacy for proper disposal.