Alendronic acid

What is alendronic acid?

Alendronic acid, also known as alendronate, is a bisphosphonate medicine used to treat or prevent osteoporosis, a condition that weakens your bones and increases the likelihood of injury. It is commonly prescribed under brand names such as Fosamax and Binosto[1]. 

What is alendronic acid used for?

Alendronic acid is a prescription only medication licensed for the treatment of osteoporosis in men and postmenopausal women. It may also be used to prevent osteoporosis in people at higher risk of bone fractures[1]. 

How does alendronic acid work?

Human bones naturally break down and rebuild over time. Alendronic acid is a bisphosphonate, and bisphosphonates work to slow down the activity of the cells that break down bone – osteoclasts. This leads to toincreased bone density and a reduced risk of fractures[1].  

Who can take alendronic acid?

Alendronic acid can be suitable for most adults over the age of 18 years old with osteoporosis or who have a high risk of fractures. This includes postmenopausal women and men experiencing bone loss. 

However, alendronic acid may not be appropriate[1]: 

• If you are allergic to alendronate sodium trihydrate  

• If you have trouble swallowing, problems with your digestion, or problems with your oesophagus, such as Barrett’s oesophagus 

• If you have kidney problems 

• If you have low calcium levels (hypocalcaemia) 

• If you have cancer or if you are undergoing chemotherapy or radiotherapy 

• If you are unable to sit or stand upright for at least 30 minutes after taking a dose  

• If you are pregnant or trying to get pregnant  

Please tell your doctor or pharmacist about any conditions you may have before starting alendronic acid and always follow the instructions in the Patient Information Leaflet[2]. 

How do you take alendronic acid?

To get the best effects from alendronic acid and minimise irritation you should take the tablet first thing in the morning, on an empty stomach, at least 30 minutes before breakfast. Swallow it whole with a full glass of tap water and do not crush or chew the tablet. It’s important not to take alendronic acid with still mineral water, sparkling mineral water, juices, milk, or tea and coffee, as these can all disrupt your body absorbing the medicine[1].  

After you’ve taken alendronic acid, do not lie down, eat, drink anything (other than water), or take any other medication for at least 30 minutes afterwards. Remain upright (sitting, standing, or walking) during this period to minimise side effects and allow for absorption[1]. 

What is the typical dosage of alendronic acid?

The usual dose of alendronic acid for adults is 70mg taken once a week, on the same day each week. In some cases, it may also be prescribed as a 10mg dose taken once daily. Always follow the dosage on the label or as prescribed by your doctor or pharmacist.   

Alendronic acid is available as tablets, soluble tablets or an oral solution[1]. If you are prescribed the liquid form, it is important to use the measuring spoon or oral syringe provided with the medication to ensure you are taking the correct dose. Kitchen teaspoons are not reliable and may lead to incorrect dosing. 

Can you stop taking alendronic acid suddenly?

You should not stop taking alendronic acid without speaking to your doctor first. Usually, your treatment will be regularly reviewed every few years. Your doctor may recommend a break in treatment, depending on your bone health, and you should follow their guidance[1]. 

What should you do if you take too much alendronic acid?

If you take more than the prescribed amount of alendronic acid, do not to make yourself vomit and do not lie down. Instead, drink a full glass of milk, remain sitting or standing upright for 30 minutes, and contact 111 for medical advice straight away[1]. 

What should you do if you forget a dose of alendronic acid?

If you miss your weekly dose of alendronic acid, you should take it the following morning as instructed. Do not take two doses on the same day. Then, continue with your regular schedule the following week[1].  

What medicines should you avoid while taking alendronic acid?

You should inform your doctor or pharmacist if you are taking any of the following medications: 

• Certain cancer treatments such as chemotherapy, bevacizumab, or thalidomide  

• Corticosteroids such as prednisolone and dexamethasone  

• NSAIDs (a type of anti-inflammatory pain killers) such as ibuprofen as these could cause digestive issues  

• Antacids for indigestion or heart burn 

• Calcium, iron, zinc and magnesium supplements including laxatives containing magnesium 

• Some antibiotics such as gentamicin, amikacin, or tobramycin 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of alendronic acid? 

 Some of the most common side effects of alendronic acid include[1]: 

• Heartburn and indigestion 

• Stomach pain 

• Diarrhoea or constipation 

• Dizziness  

• Headaches  

• Drowsiness 

• Hair loss 

• Muscle, joint, or bone aches and pains  

Rare but more serious side effects include[1]: 

• Difficulty or pain when swallowing (may be a sign of oesophageal ulcers) 

•  Pain in your thigh, hip or groin may be signs of a fracture in your thigh bone  

• A severe rash made worse by sunlight Severe bone, joint or muscle pain 

• Dental problems such as mouth sores, toothache, and swelling or pain in the mouth or jaw 

• Black or red poo as these may be signs of bleeding in your stomach  

• Blurred vision or painful eyes 

• Muscle cramps, spasms, or tingling may indicate low calcium levels in your blood  

• Flu-like symptoms including a raised temperature  

• Ear pain with or without discharge from the ear  

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about alendronic acid

Is alendronic acid a painkiller? 

No, alendronic acid does not relieve pain and it is not a painkiller. Instead, its purpose is to strengthen bones and reduce the risk of fractures[1]. 

Can I drink alcohol while taking alendronic acid? 

Yes, it’s usually safe to drink alcohol in moderation while taking alendronic acid. However, excessive alcohol may interfere with how well you react to the medicine so should be avoided[1]. 

Can I take alendronic acid long-term? 

Yes, alendronic acid is usually used long term for at least 3 to 5 years. Your doctor will review your medication every few years to decide whether you should continue or take a break[1].  

Can I take alendronic acid with food? 

No, you should take alendronic acid on an empty stomach and then wait at least 30 minutes after taking it before eating anything. This is because food will reduce the absorption of the medication in your body and reduce its efficacy[1]. 

For the official NHS guide to alendronic acid, visit their website.