Fosamax (alendronic acid)
Also known as: Alendronic acid · Alendronate · Fosamax
Alendronic acid, sold as Fosamax and other brands, is one of the most commonly used tablets for osteoporosis. Taken correctly, it can reduce fracture risk. Taking it correctly matters, so let me walk you through the practical points.
Calm, careful medication review by a consultant rheumatologist.
What this medicine is
Alendronic acid is a bisphosphonate. It helps slow down the cells that break down bone, which supports bone density and reduces the risk of fracture.
Uses and context
It is often used in postmenopausal osteoporosis, some cases of osteoporosis in men, and steroid-related bone loss. It is not a treatment for bone pain on its own.
How this relates to rheumatology care
In clinic I check your DEXA scan, fracture risk (for example using FRAX), calcium and vitamin D, kidney function, and any dental issues. I discuss how long to stay on treatment and when a drug holiday might make sense.
What safety checks may matter
Take on an empty stomach, first thing in the morning
Swallow with a full glass of plain water only
Stay upright, sitting or standing, for at least 30 minutes after the dose
Wait at least 30 minutes before food, drink, calcium or other medicines
Adequate calcium and vitamin D
Regular DEXA and treatment-duration review
Side effects and red flags
If you have emergency symptoms such as severe allergic reaction, breathing difficulty, chest pain, stroke-like symptoms, severe abdominal pain, vomiting blood, black stools, sudden vision loss, severe infection symptoms, or severe weakness or confusion, please seek urgent medical care first rather than waiting for a WhatsApp reply.
Chest pain, difficulty swallowing, or new heartburn after starting
Black stools or vomiting blood
Severe jaw pain, non-healing dental problems or loose teeth
Unusual thigh or groin pain
Severe muscle, bone or joint pain that is new
Signs of severe allergic reaction
Things worth knowing day to day
Do not lie down for 30 minutes after taking the tablet.
Tell your dentist you are on a bisphosphonate before major dental work.
Not usually suitable if kidney function is significantly reduced.
Discuss any planned pregnancy with your doctor.
Questions patients often ask me about this medicine
Speak with me
If you have been told you have low bone density or a high fracture risk, please message my clinic. I would like to help you use bone medicines safely.
Other medications used in rheumatology care
This page is for general education only and does not replace medical advice. Please consult a qualified healthcare professional for diagnosis and treatment. Do not start, stop, or change any medicine without advice from your doctor.