What Are the Side Effects of Thalidomide?

Many people have heard of the thalidomide tragedy. Around the globe in the 1950s and 1960s, many expecting mothers were given a medication they thought was going to treat their morning sickness. Instead, it caused severe birth defects. The most famous one was phocomelia, a birth defect that causes shortened arms or legs. 

Since then, medication safety standards have been developed that require medications to be tested for potentially harmful effects on a developing baby before being given to the public. And because thalidomide is beneficial for other health conditions, it’s accessible with a Risk Evaluation and Mitigation Strategy (REMS) medication safety program. This program helps make sure that thalidomide is used safely, but there are still some side effects to be aware of. 

Here, we’ll discuss potential thalidomide side effects, what you can do to manage them, and when to call your care team. 

What is thalidomide?

Thalidomide (Thalomid) is an oral medication that treats a type of blood cancer called multiple myeloma. It’s also used to treat certain skin reactions caused by leprosy. This is a bacterial infection that can result in skin, nerve, and other body-wide side effects. It specifically treats a type of leprosy reaction called erythema nodosum leprosum (ENL).

How does thalidomide work for multiple myeloma and leprosy?

Thalidomide is a type of immunomodulator. It can boost or suppress your immune system depending on the situation it’s used in. It’s also considered an angiogenesis inhibitor, meaning it can cut off blood supply to cancer cells. 

But what does this mean? 

In multiple myeloma, thalidomide can interfere with specific messages that are normally involved in cancer cell growth and survival. At the same time, it can also promote the production of T cells and natural killer cells, which help destroy cancer cells. T cells and natural killer cells are white blood cells that are an important part of your immune system. And, by cutting off the blood supply to cancer cells, thalidomide starves the cancer of its fuel source.

In leprosy, thalidomide helps treat and prevent ENL by suppressing inflammation signals that are made by the immune system. 

Common thalidomide side effects

Thalidomide has many possible side effects to be aware of. The most common side effects include:

• Anxiety

• Confusion

• Constipation

• Decreased appetite/weight loss

• Dizziness

• Feeling tired or agitated

• Fever

• Headache

• Low calcium levels

• Low white blood cells 

• Muscle weakness

• Nerve damage, which includes feelings of numbness, burning, or tingling in your fingers or toes

• Nausea

• Rash/dry skin

• Swelling

• Trouble breathing

• Weight gain 

Serious thalidomide side effects

Some of thalidomide’s side effects can also be serious. If you experience any of these side effects, it’s recommended to seek medical attention right away.

Birth defects

As mentioned, phocomelia is the most common birth defect linked to thalidomide. But other birth defects — such as heart disease, malformed kidneys, and death — have also been reported. 

Because of these risks, thalidomide is only available in the U.S. under a restricted distribution program called the THALOMID REMS program. This helps make sure that developing babies aren’t exposed to thalidomide. Thalidomide also has a boxed warning about birth defects. This is the most serious type of warning the FDA can give to a medication.

Blood clots

Thalidomide can raise your risk of blood clots, especially when it’s taken with medications like dexamethasone. Symptoms of a blood clot include shortness of breath, chest pain, and swelling of your arms or legs. Thalidomide also has a boxed warning about this risk. 

Elevated HIV viral load

If you’ve been diagnosed with HIV, it’s possible that thalidomide could cause the amount of virus in your body to go up. However, if you take HIV medications, it’s not clear if this risk is fully relevant. Just to be safe, your care team may monitor your viral loads more closely while taking thalidomide. 

Low heart rate

Thalidomide can cause low heart rate, which could result in fainting. This side effect is usually mild, but it can be serious in some cases. 

Skin reactions

A mild rash is common, but more severe skin reactions can occur. If the rash peels or blisters, this could be a sign of a more serious skin reaction called Stevens-Johnson syndrome or toxic epidermal necrolysis (SJS/TEN). SJS/TEN is a medical emergency.

When should I contact my healthcare provider about side effects from thalidomide?

If you notice any of these side effects, it’s recommended to reach out to your healthcare provider: 

• Chest pain

• Dizziness or feeling faint

• Fever

• Numbness, burning, or tingling in the hands or feet

• Possible pregnancy

• Problems with vision, speech, or balance

• Rapid heart beat

• Rash or peeling skin

• Severe headache or confusion

• Severe itching

• Shortness of breath 

• Sudden numbness or weakness

• Swelling of the arms, legs, lips, mouth, tongue, or throat

• Trouble swallowing

What can I do to manage the side effects of thalidomide?

Depending on your situation, you may be able to manage or prevent certain side effects at home. Here are some tips to keep in mind if you’re taking thalidomide. 

Blood clots

You may need to take medication to prevent blood clots while taking thalidomide. Options include an antiplatelet medication, such as aspirin, or a blood thinner, such as warfarin (Coumadin), apixaban (Eliquis), or rivaroxaban (Xarelto). 

However, if you’re already taking a blood thinner for a previous blood clot or a different condition, you don’t need another medication to prevent blood clots. 

Constipation

Constipation can be treated with diet changes, an exercise routine, and over-the-counter (OTC) stool softeners or laxatives. Ask your healthcare provider if OTC medications are safe for you to take. 

Dizziness

When you have been laying down for a long period of time, you should slowly bring yourself up to a seated position and remain there for a few minutes before standing. This helps control dizziness. 

Drowsiness

Taking thalidomide at night can help minimize sleepiness during the day. Avoiding alcohol and minimizing other medications that can make you sleepy also helps.

Nausea

Thalidomide doesn’t usually cause nausea. But if you develop nausea while taking thalidomide, your care team can prescribe an anti-nausea medication, such as ondansetron (Zofran) or prochlorperazine (Compazine).

Prevention of pregnancy

It’s important that you follow all the requirements of the THALOMID REMS program. 

If you have the ability to become pregnant, and are sexually active, you must use two effective forms of birth control while taking thalidomide. For example, using a condom while also taking birth control pills. There are some forms of birth control that are not acceptable, so talk to your care team about options that work for you. Regular pregnancy tests are also required while taking thalidomide. You’ll be asked to complete a mandatory survey every month that ensures you understand the instructions to prevent pregnancy. 

If you’re a female who cannot become pregnant due to surgical or natural menopause, you’re only required to complete the mandatory survey every 6 months. No pregnancy tests or birth control methods are required.

If you’re a male who is sexually active with a female who could become pregnant, you must use a condom every time you have sex. This still applies if you have had a vasectomy. You will also be asked to complete a mandatory survey every month.

To further prevent pregnancy-related risks, all people taking thalidomide should not share the medication with others or donate blood. If you’re a male, you also shouldn’t donate semen.

Rash

You should contact your care team if a rash occurs so they can evaluate its severity. If the rash is considered mild, it can often be treated by stopping thalidomide for a while and treating with a topical moisturizer or steroid. Thalidomide can often be restarted safely at a lower dose. 

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Written by:

Rachel Feaster, PharmD, BCOP, BCPS

Rachel Feaster has over 10 years of professional experience in ambulatory, inpatient, pharmacogenomics, and oncology care. She is board certified in oncology and pharmacotherapy.

Edited by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

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