Rapamune (sirolimus) is a brand-name prescription medication. The Food and Drug Administration (FDA) has approved it to:

  • Help prevent the rejection of kidney transplants in adults and certain children ages 13 years and older.* Rejection occurs when the immune system attacks a transplanted organ.
  • Treat a condition called lymphangioleiomyomatosis in adults. The condition affects the lungs, kidneys, and lymphatic system, and it may cause difficulty breathing.

Rapamune is available as an oral tablet and oral solution. There are generic versions of both of these forms. Rapamune belongs to a class of drugs called mammalian target of rapamycin (mTOR) blockers.

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

* For this purpose, Rapamune may be prescribed for a time with two medications. One is a corticosteroid such as prednisone (Rayos). The other is an immunosuppressant drug known as cyclosporine (Neoral, Sandimmune, Gengraf).

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

Before you start taking Rapamune, your doctor will recommend the best dosage for you.

Rapamune forms

Rapamune comes in two forms: an oral tablet and oral solution. To learn about some differences between the forms, see “Frequently asked questions” below.

Rapamune strengths

The oral tablets are available in these strengths: 0.5 milligrams (mg), 1 mg, and 2 mg.

The oral solution is available in one strength: 1 mg per milliliter (mg/mL). The solution comes in a bottle containing 60 mg per 60 mL.

Typical dosages

Your doctor may start you on a low dosage. They’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Dosage for preventing the rejection of a kidney transplant

The dosage of Rapamune that your doctor recommends to help prevent the rejection of a kidney transplant depends on your risk of rejection. The risk of rejection may be higher in people:

  • whose body rejected a donor kidney in the past
  • who are Black
  • who have high levels of specific antibodies (proteins in the immune system)

Your doctor can help determine your risk of injection.

You’ll start off by taking a loading dose of Rapamune. A loading dose is an increased dose of medication taken when you first start treatment. This helps the drug begin working quickly in your body.

After your loading dose, your doctor will switch you to a maintenance dose. This is the dose of Rapamune that you’ll take every day. It’s a lower dose than the loading dose.

Below is a standard dosage chart for Rapamune for when the drug is used to help prevent the rejection of kidney transplants.

Rapamune loading dosageRapamune maintenance dosage
Low to moderate risk of rejection6 mg on first day of treatment2 mg once per day
High risk of rejectionup to 15 mg on first day of treatment5 mg once per day

Note: When Rapamune is used to help prevent kidney transplant rejection, the drug may be prescribed for a time with two medications. One is a corticosteroid such as prednisone (Rayos). The other is an immunosuppressant drug known as cyclosporine (Neoral, Sandimmune, Gengraf). Your doctor can provide you with dosage details for these medications.

Dosage for treating lymphangioleiomyomatosis

In most cases, your doctor will prescribe a Rapamune starting dose of 2 mg per day. Then they may adjust your dose to reach the amount that’s right for you.

Children’s dosage

Rapamune is approved to help prevent the rejection of kidney transplants in children ages 13 years and older. The medication is approved for use only in children who have a low to moderate risk of kidney rejection.* It’s not known if this drug may be safe or effective in children with a high risk of rejection. In addition, Rapamune is not approved to treat lymphangioleiomyomatosis in children.

Your child’s Rapamune dosage depends on their weight. In the section below, kilograms is abbreviated as kg, and 1 kg equals about 2.2 pounds (lb).

* For details, see “Dosage for preventing the rejection of a kidney transplant” above.

Children weighing less than 40 kg

If your child weighs less than 40 kg (about 88 lb), their dose will be based on their body surface area (BSA). This is a calculation that uses a person’s height and weight to determine how much surface area their body has. Your child’s BSA will be calculated by their doctor or pharmacist. BSA is measured in meters squared (m2).

The recommended loading dose for children weighing less than 40 kg is 3 mg/m2 once on their first day of treatment. After this, the maintenance dosage is usually 1 mg/m2 once per day. Your child’s doctor may use a dosage calculator to determine Rapamune doses.

Children weighing 40 kg or more

If your child weighs 40 kg (about 88 lb) or more, the dosage will likely be the same as for adults taking Rapamune to help prevent kidney rejection. There’s a loading dose of 6 mg on the first day. After that, your child will usually have a maintenance dosage of 2 mg once per day.

Note: When Rapamune is used to help prevent kidney transplant rejection, the drug may be prescribed for a time with two medications. One is a corticosteroid such as prednisone (Rayos). The other is an immunosuppressant drug known as cyclosporine (Neoral, Sandimmune, Gengraf). Your child’s doctor can provide you with dosage details for these medications.

Long-term treatment

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

Below are the answers to some frequently asked questions about Rapamune.

What Rapamune dosage should be taken during pregnancy?

There’s not a recommended Rapamune dosage to take while pregnant because the drug is usually not taken during pregnancy.

Rapamune has not been studied in pregnant people, so it’s not known what effects the drug may have on a developing fetus. In animal studies, the drug increased the risk of congenital anomalies (commonly known as birth defects) and pregnancy loss. Due to these risks, doctors usually will not prescribe Rapamune to pregnant people.

If you’re pregnant or planning a pregnancy, talk with your doctor about treatments other than Rapamune.

Are there advantages and disadvantages of taking Rapamune oral solution vs. oral tablets?

An advantage of the oral solution form of Rapamune is you don’t have to swallow tablets. The tablet form of the drug cannot be broken or crushed. So if you have trouble swallowing tablets whole, your doctor may recommend the oral solution.

However, Rapamune oral solution needs to be mixed with either water or orange juice and swallowed right away. (For more information, see “How to take Rapamune” below.) The oral solution also needs to be refrigerated and used within 1 month of opening the bottle.

Your doctor can advise you on whether Rapamune oral solution or oral tablets are right for you.

If my doctor switches me between Rapamune oral tablets and oral solution, will my dose be the same?

Yes, your dose of Rapamune will remain the same whether you take oral tablets or the oral solution. Both forms have been shown to have the same effects.

As an example, if you’re prescribed 2-mg oral tablets and your doctor switches you to the oral solution, your dose would still be 2 mg, which is 2 mL of solution.

If you have additional questions, talk with your doctor or pharmacist.

Rapamune is available as both an oral tablet and an oral solution. Both forms of Rapamune are taken once per day. It may be helpful to take Rapamune around the same time each day. This helps maintain a steady level of the drug in your body so Rapamune can work effectively.

You can take your dose of Rapamune with food or without food. However, it’s important to take it consistently in the same way each day. This is because food can affect the way that your body absorbs the drug. So if you start taking Rapamune with food, you should continue taking it each day with food. And if you first take the medication without food, be sure to keep taking it on an empty stomach each day.

If you take Rapamune tablets, swallow them whole. You should not break, crush, or chew the tablets. If you have difficulty swallowing your Rapamune tablets, ask your doctor about switching to the oral solution.

For step-by-step instructions on how to take the oral solution form of Rapamune, see the instructions for use.

If you have questions about taking either form of Rapamune, your doctor or pharmacist can advise you on the drug’s dosage and directions.


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 Rapamune in an easy-open container. They also may recommend tools that can make it easier to open bottles.

The Rapamune dosage a doctor prescribes may depend on several factors. These include:

  • the type and severity of the condition you’re using Rapamune to treat
  • other medications you take
  • use of cannabis (often called marijuana) or cannabidiol (CBD) products
  • the form of Rapamune you take
  • body surface area or body weight

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

Dosage adjustments

In some cases, your doctor may need to adjust your dose of Rapamune based on other conditions you have. For example, people with liver problems may be prescribed a lower dose of the medication. This is because Rapamune is broken down by your liver. If your liver isn’t working well, the drug may build up in your body, which can increase your risk of side effects.*

Also, certain medications may interact with Rapamune. Sometimes, your doctor may recommend a higher or lower dose of Rapamune if you’re taking drugs that can interact with it. Examples of these medications may include:

  • cimetidine (Tagamet)
  • diltiazem (Cardizem CD)
  • fluconazole (Diflucan)
  • carbamazepine (Tegretol)
  • phenytoin (Dilantin)

Using cannabis or CBD products with Rapamune may increase the level of Rapamune in your body. This can lead to side effects.* If you use cannabis or CBD products, talk with your doctor. They may lower your dose of Rapamune.

In addition, children’s dosages may sometimes need to be changed. The dosage for children weighing less than 40 kg (about 88 lb) is based on body surface area. (For details, see “Rapamune dosage” above.) If your child’s height or weight changes during treatment, their doctor may adjust the dosage of Rapamune.

Before starting Rapamune treatment, tell your doctor about any other medical conditions you have or medications you take. They can recommend the right dosage for you.

* To learn about side effects of Rapamune, see this article.

If you miss a dose of Rapamune, ask your doctor or pharmacist when to take your next dose. They may recommend that you take the missed dose right away. However, if it’s almost time for your next dose, they may advise you to skip the missed dose, then take the next dose as scheduled.

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.

It’s important that you do not take more Rapamune than your doctor prescribes. For some medications, taking more than the recommended amount may lead to side effects or overdose.

If you take more than the recommended amount of Rapamune

Call your doctor right away if you believe you’ve taken too much Rapamune. 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 Rapamune, they’ll 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 Rapamune without your doctor’s recommendation. If you have questions about the dosage of Rapamune that’s best for you, talk with your doctor.

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

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.