From the Guidelines
Alendronate can cause severe side effects, including osteonecrosis of the jaw and atypical subtrochanteric fracture, in addition to mild upper GI symptoms, as reported in the 2017 American College of Physicians guideline update 1. The most concerning side effects of alendronate include:
- Osteonecrosis of the jaw
- Atypical subtrochanteric fracture These side effects are associated with the use of bisphosphonates in general, according to the guideline update 1. In addition to these severe side effects, alendronate can also cause:
- Mild upper GI symptoms, such as heartburn, abdominal pain, and nausea
- Musculoskeletal pain affecting bones, joints, or muscles To minimize the risks associated with alendronate, patients should:
- Take the medication with a full glass of water first thing in the morning
- Remain upright for at least 30 minutes after taking it
- Ensure adequate calcium and vitamin D intake
- Inform their dentist about alendronate use before dental procedures It is essential to weigh the benefits of alendronate against the potential harms, as the medication has been shown to reduce the risk of hip and vertebral fractures in women with known osteoporosis, as stated in the guideline update 1.
From the FDA Drug Label
Alendronate sodium tablets, USP can cause serious side effects including: Esophagus problems Low calcium levels in your blood (hypocalcemia) Bone, joint, or muscle pain Severe jaw bone problems (osteonecrosis) Unusual thigh bone fractures
The worst side effects of Alendronate (Fosamax) are:
- Esophagus problems: irritation, inflammation, or ulcers of the esophagus which may sometimes bleed
- Low calcium levels in your blood (hypocalcemia): may cause spasms, twitches, or cramps in your muscles, numbness or tingling in your fingers, toes, or around your mouth
- Bone, joint, or muscle pain: severe pain
- Severe jaw bone problems (osteonecrosis): may happen when you take alendronate sodium tablets, USP
- Unusual thigh bone fractures: symptoms may include new or unusual pain in your hip, groin, or thigh 2
From the Research
Worst Side Effects of Alendronate (Fosamax)
- Osteonecrosis of the jaw (ONJ) and atypical femoral fractures (AFFs) have been reported in long-term users of alendronate, as seen in a case study where a postmenopausal woman developed both conditions within 6 months of each other while taking the medication 3.
- Musculoskeletal adverse effects, such as acute arthralgia and acute back pain, have been observed in patients taking alendronate, particularly in those starting treatment with once weekly dosage regimens 4.
- Gastrointestinal adverse events, including esophageal and gastric mucosal toxicity, have been reported in some studies, although the risk is considered low and not significantly higher than with placebo 5, 6.
- Serious adverse events, such as hip and wrist fractures, have been observed in some studies, although the evidence is uncertain and the effects of alendronate on these outcomes are not well established 7.
Specific Side Effects
- Acute arthralgia: 12.6% of patients taking alendronate 70 mg once weekly reported this side effect 4.
- Acute back pain: 9.1% of patients taking alendronate 70 mg once weekly reported this side effect 4.
- Osteonecrosis of the jaw (ONJ): a rare but serious side effect that has been reported in long-term users of alendronate 3.
- Atypical femoral fractures (AFFs): a rare but serious side effect that has been reported in long-term users of alendronate 3.
Prevention and Management of Side Effects
- Starting treatment with lower daily dosages of alendronate (10 mg daily) for a short period before switching to once weekly dosage regimens may help reduce the risk of musculoskeletal adverse effects 4.
- Monitoring patients for signs and symptoms of ONJ and AFFs, such as jaw pain or difficulty walking, is important for early detection and management of these conditions 3.