Interactions during therapy with bisphosphonates
The interaction of the bisphosphonates consists particularly in the fact that they have chemical properties that bind certain positively charged substances. These are for example calcium, iron or magnesium. This binding means that both fewer bisphosphonates and fewer other substances are absorbed into the body.
Since only a very small proportion of the bisphosphonates reach the large bloodstream and the bones anyway, this interaction can greatly weaken the effect of the bisphosphonates. If there is too little free calcium in the body, which is needed to build stable bones, the bones lose their strength. To prevent this, the bisphosphonates should be taken at least half an hour before meals.
Bisphosphonates and renal insufficiency
Bisphosphonates are mainly excreted via the kidney (renal elimination). This must be taken into account in patients with renal dysfunction. In patients with mild to moderate renal insufficiency, the dose may have to be adjusted. In patients with severe renal insufficiency, i.e. a creatinine clearance of less than 30-35 ml/min, the use of bisphosphonates is contraindicated. It is also known that – irrespective of pre-existing renal failure – too rapid infusion of bisphosphonates can lead to acute renal failure due to complex formation with calcium ions.
Summary
In summary, it can be said that necroses of the jawbone caused by therapy with bisphosphonate as a side effect are a rare complication. The cause for the occurrence is still largely unclear. The symptoms are uncharacteristic and mostly painless.
The therapy consists in the removal of the lost bone and restoration of the bone structure. Prophylaxis consists in the restoration of the teeth followed by careful oral hygiene and monitoring by the dentist.