Hydrea (hydroxyurea) is a brand-name prescription medication. The Food and Drug Administration (FDA) has approved it to treat the following conditions in adults:

Hydrea belongs to a class of drugs known as antimetabolites. It comes as an oral capsule. Hydrea’s active drug, hydroxyurea, is available in generic form.

* For this use, Hydrea is given along with chemotherapy and radiation therapy.

Dosage summary

The following chart briefly summarizes Hydrea’s dosage. Your doctor will determine the dosage that’s best for you.

Hydrea formHydrea strengthRecommended dosage
oral capsule500 milligrams (mg)varies by individual, based on body weight

For information about the dosage of Hydrea, including its strength and how to take the drug, keep reading. For a comprehensive look at Hydrea, see this article.

This article describes typical dosages for Hydrea provided by the drug’s manufacturer. When taking Hydrea, always follow the dosage prescribed by your doctor.

Below is important information about Hydrea’s dosage for its approved uses.

Hydrea form

Hydrea comes as an oral capsule.

Hydrea strength

Hydrea comes in a 500-milligram (mg) strength.

Typical dosages

Typically, your doctor will start by prescribing a dosage that’s based on your weight in kilograms (kg).* They might base it on your actual body weight (what you weigh when you get on a scale). Or they might use a formula to calculate what’s referred to as your “ideal” weight. They’ll use whichever weight is lower to calculate your Hydrea dosage.

Your doctor will typically adjust your dosage over time to reach the amount that’s right for you. They’ll ultimately prescribe the smallest dosage that provides the desired effect.

A typical dosage of Hydrea may be 15 mg per kg of body weight taken once daily. For example, a person weighing 67 kg (about 147 pounds) would take 1,000 mg of Hydrea once daily. The manufacturer of Hydrea does not list a maximum dose.

Be sure to take the dosage your doctor prescribes for you. The sections below describe dosing for the types of cancer that Hydrea treats. However, your doctor will determine the best dosage to fit your needs.

* 1 kg equals about 2.2 pounds (lb).

Dosage for skin cancer of the head and neck

Hydrea is approved to treat squamous cell carcinoma (SCC) of the head and neck (except for cancer that occurs on the lips). When it’s used for this condition, Hydrea is given along with chemotherapy and radiation.

The manufacturer of Hydrea has not given exact dosage recommendations for SCC. Your dosage will be based on your body weight and other factors (see “Factors that can affect your dosage” below).

Dosage for chronic myeloid leukemia

Hydrea is approved to treat chronic myeloid leukemia (CML). The drug’s manufacturer has not given exact dosage recommendations for CML. Your dosage will be based on your body weight and other factors (see “Factors that can affect your dosage” below).

Long-term treatment

Hydrea is meant to be a long-term treatment. If you and your doctor determine that Hydrea is safe and effective for you, you’ll likely take it long term.

The Hydrea dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of your cancer
  • how your body responds to treatment with Hydrea, such as any side effects you have
  • how effective Hydrea is for your condition
  • your body weight, including any changes in your weight over time

Other medical conditions you have can also affect your Hydrea dosage.

Dosage adjustments

Your doctor may decrease your dosage of Hydrea if you are age 65 years or older, or if you experience certain side effects while taking Hydrea.

If you have kidney problems, your doctor might also decrease your dosage. If you have end stage renal disease, you may need renal dosing of Hydrea. This means your doctor may prescribe half the typical amount of Hydrea.

You can take Hydrea capsules with or without food. You should swallow the capsules whole. Do not open, chew, or break the capsules. And do not touch capsules that have been damaged or broken.

Hydrea is cytotoxic (harmful to living cells), and opening or breaking the capsules can be dangerous. Be sure to wash your hands with soap and water when you handle Hydrea. This includes before and after touching the drug capsules or containers.

If you have trouble swallowing capsules, see this article for tips on how to take this form of medication. You can also talk with your doctor or pharmacist.

Accessible drug labels and containers

If you’re having trouble reading your prescription label, talk with your doctor or pharmacist. Some pharmacies offer labels with large print, braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.

If you’re having trouble opening medication bottles, ask your pharmacist about putting Hydrea in an easy-open container. They also may recommend tools that can make it easier to open bottles.

If you miss a dose of Hydrea, contact your doctor. They can recommend what you should do. Do not double up on doses of Hydrea to make up for a missed dose.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm or using a timer. You could also download a reminder app on your phone.

If you take more Hydrea than your doctor prescribes, you may develop serious side effects.

It’s important that you do not take more Hydrea than your doctor advises.

Symptoms of an overdose

Overdose symptoms of Hydrea can include skin reactions such as:

  • soreness
  • skin that turns red, purple, or darker in color
  • swelling of the palms of the hands and soles of the feet
  • scaly skin on the hands and feet
  • sores inside the mouth

If you take more than the recommended amount of Hydrea

Call your doctor right away if you believe you’ve taken too much Hydrea. Another option is to call the American Association of Poison Control Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.

The dosages in this article are typical dosages provided by the drug manufacturer. If your doctor recommends Hydrea for you, they will prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes for you.

As with any drug, never change your dosage of Hydrea without your doctor’s recommendation. If you have questions about the dosage of Hydrea that’s right for you, talk with your doctor.

Besides learning about dosage, you may want other information about Hydrea. These additional articles might be helpful to you:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.