Alendronate - Uses, Side Effects, and More

What are the most common side effects of alendronate?

The most common side effects of alendronate are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

• Stomach pain
• Heartburn
• Constipation
• Diarrhea
• Upset stomach or indigestion
• Bone, joint, or muscle pain (see below)
• Nausea

There may be other side effects of alendronate that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of alendronate?

While less common, the most serious side effects of alendronate are described below, along with what to do if they happen.

Severe Allergic Reactions. Alendronate may cause allergic reactions, which can be serious. Stop taking alendronate and get help right away if you have any of the following symptoms of a serious allergic reaction.

• Breathing problems or wheezing
• Racing heart
• Fever or general ill feeling
• Swollen lymph nodes
• Swelling of the face, lips, mouth, tongue, or throat
• Trouble swallowing or throat tightness
• Itching, skin rash, or pale red bumps on the skin called hives
• Nausea or vomiting
• Dizziness, feeling lightheaded, or fainting
• Stomach cramps
• Joint pain

Esophagus Problems. Taking alendronate by mouth may irritate the esophagus or upper part of your gastrointestinal (GI) tract. This irritation can be worse in people who already have stomach or esophagus problems. In some cases, it can lead to problems such as ulcers, bleeding, or tears in the esophagus, which may require hospitalization. Stop taking alendronate and call your healthcare provider right away if you have any of the following symptoms.

• Trouble or pain while swallowing 
• Chest pain
• New or worsening heartburn

Low Calcium Level (Hypocalcemia). Alendronate can cause low calcium levels, also known as hypocalcemia, which can be serious. Decreased calcium levels can cause a rare dangerous heart rhythm problem called QT prolongation and torsade de pointes. Some people have a higher risk of this, including people who are older, have other people in their family who have had these conditions, have low potassium or magnesium, or who take some medicines for other heart rhythm problems. Call your healthcare provider if you have any of the following symptoms.

• Changes in your heart rate or rhythm, such as fast or skipping heartbeat
• Fainting
• Numbness, tingling, or burning sensation in your arms, feet, or face (paresthesia)
• Muscle pain, spasms, twitching, or cramps
• Seizures

Severe Pain in the Bones, Joints, or Muscles. Alendronate may cause severe pain in the bones, joints, or muscles (musculoskeletal pain). The pain can be severe enough that it could be difficult to carry out normal activities. Call your healthcare provider if you experience severe pain while on alendronate.

Severe Jawbone Problems (Osteonecrosis). Alendronate can rarely cause severe jawbone problems, also called osteonecrosis of the jaw. In this condition, your jawbone may get damaged due to reduced blood flow. You may be at higher risk if you are undergoing certain dental procedures (such as a tooth extraction or dental implants), if you have poor oral health, or if you have cancer or certain other conditions. You may be told to see a dentist before starting alendronate and to practice good mouth care. Call your healthcare provider right away if you experience any of the following symptoms of jaw osteonecrosis.

• Jaw pain or discomfort
• Mouth sores
• Loose teeth

Unusual Thigh Bone Fractures. Alendronate may cause an increased risk for fractures in your thigh bone, even with a light force. Call your healthcare provider if you experience new or unusual pain in your thigh, hip, or groin.