Meds and you

30 September 2013


Risedronate is a biphosphonate. Biphosphonates are drugs that prevent the loss of bone mass and are used to treat osteoporosis.


Risedronate is the active ingredient of Actonel Once-a-week tablets (Nappi code: 701117-001).

General information

Risedronate is a biphosphonate. Biphosphonates are drugs that prevent the loss of bone mass and are used to treat osteoporosis.

In South Africa risedronate is registered for the treatment of osteoporosis in postmenopausal woman. It is furthermore indicated for the treatment of Paget's disease, a disorder which can lead to weakness and malformation of bones.

Risedronate tablets should be taken with a full glass of plain water first thing after getting up in the morning. Wait at least 30 minutes after taking the tablet - if you can wait longer the tablet will be absorbed better - before having the first meal of the day, any beverage or medication. After swallowing your risedronate tablet do not lie down - remain upright (sitting or standing) for at least 30 minutes and until after your first food of the day. This will help the tablet to reach your stomach quickly and prevent it from sticking to the throat (oesophagus) where it may cause irritation, ulcers, bleeding or even perforation.

Do not bite, crush or suck risedronate tablets as this may cause mouth ulcers and increase the risk of oesophageal irritation. Do not take risedronate at bedtime.

A calcium supplement with vitamin D and a vitamin C supplement may aid in the formation of new bone tissue if dietary amounts are not adequate. These should however not be taken at the same time as risedronate as it will affect risedronate absorption.

How does risedronate work?

Risedronate works by reducing the activity of osteoclasts, the cells that cause bone loss, without affecting osteoblasts, the cells responsible for building new bone. Risedronate ultimately enables you to add bone because it allows your body's osteoblasts to continue to work while osteoclasts are stopped from breaking down bone. Your body will no longer lose more bone than your cells are making and will slowly begin to add new bone. Exercise will help even more.

Fast facts

Drug schedule: schedule 3

Available as: risedronate is available as tablets.

What does it do? Risedronate prevents bone degeneration and increases bone mass

Overdose risk: medium

Dependence risk: low

Is risedronate available as a generic? no

Is risedronate available on prescription only? yes

User information

Onset of effect: several days

Duration of action: up to 16 months

Dietary advice: for risedronate to be effective, you must take the tablets without food or other medications. Take the medication with plain water, not mineral water. The minerals may have a possible effect on risedronate absorption.

Stopping this medicine: do not stop using this medication abruptly as it may cause a recurrence of the original symptoms being treated. Consult with your doctor prior to discontinuing treatment.

Special precautions

Consult your doctor before using this drug if:

- you have an oesophageal disease or battle to swallow

- you are unable to stand or sit upright for at least 30 minutes

- your blood levels of calcium are low

- you have kidney disease

Pregnancy: avoid. Potential risk to the foetus has been reported. Consult your doctor before use, or if you are planning to fall pregnant.

Breastfeeding: avoid. It is unknown how this medication may affect your baby. Consult your doctor before use.

Infants and children: this medication is not intended for use in children.

The elderly: no special precautions need to be taken.

Driving and hazardous work: no special precautions need to be taken.

Alcohol: alcohol may enhance stomach irritation. It is also a risk factor for developing osteoporosis.

Possible side effects

Side effect Frequency
Consult your doctor

Common Rare Only if severe In all cases
abdominal pain/ diarrhoea x
x x
stomach/duodenal ulcers
diarrhoea/constipation x
muscle and/or bone pain x
headache x
skin rash


Drug interactions:

aminoglycoside antibiotics increased risk of low calcium levels in body
antacids, iron and mineral supplements, calcium-containing products reduced risedronate absorption. Take at least 2 hours from taking risedronate.
non-steroidal anti-inflammatory drugs (NSAIDs) and aspirin increased possibility of upper gastro-intestinal events

Overdose action

Seek immediate medical advice. Patient should try to remain upright.

Recommended dosage

Adults, oral: 35 mg once a week on the same day each week.

This material is not intended to substitute medical advice, but is for informational purposes only.

Please consult a physician for specific treatment and recommendations.


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