Molar medication

For many people, particularly the elderly or those with neurodegenerative disorders, remembering when to take medication can be a problem.

To help solve this issue, researchers in Germany have developed an intelligent drug-filled tooth implant, Intellidrug, that administers medicine as and when the patient needs it.

The device is designed as a dental prosthesis consisting of a drug-filled reservoir, a valve, two sensors and number of electronic components, including micro-actuators. The entire implant is small enough to fit inside two artificial molars at the back of the mouth where it will look similar to the patient's natural teeth and will still allow the patient to speak and eat freely.

Dr Thomas Velten was part of the team at the

that developed the device. He said that Intellidrug would be of great help to a number of patients, not only the elderly. One of the target groups for the project is people who are suffering from long-term conditions such as diabetes or hypertension who require regular medication.

'It is important for some conditions that there is a constant level of drug in the blood plasma,' said Velten. 'Also, for people at risk from heart attacks, these attacks commonly take place very early in the morning when the patient is asleep and cannot self-medicate. With this system we can time the dosage to take place — even when the patient is sleeping.'

He explained that the system enables doctors to keep close control over the amount of drug administered.

'We can programme the time when the drug is to be administered and the exact amount needed,' said Velten. 'This means we can keep a constant level of the drug in the blood plasma and we can easily adjust the dosage in line with the patient's needs, dependant on sex or weight.'

Once the device is fitted, saliva in the mouth enters the reservoir via a membrane and dissolves the solid drug, forming a solution. When the system is triggered, a valve opens and allows a controlled amount of this saturated solution to flow into the mouth where it is then absorbed by the mucous membranes in the patient's cheeks.

The device is fitted with two sensors. The first is a fill level sensor that measures the concentration of the drug in the reservoir. It alerts the patient when the concentration of drug falls below a certain level and Velten said that, at present, the prototype can contain enough medication to last for around two weeks.

The prosthesis operates much like a drawer, he said, to allow it to be simply refilled with a new tablet or for the batteries to be replaced. The batteries will be specially designed, just like those commonly used in other medical implants, he added.

The second sensor detects how much of the drug solution has been administered by monitoring the flow of the liquid through the valve.

These two sets of data, along with information about the battery, are then sent via a wireless link to a remote control which shows the patient or the doctor whether or not the reservoir needs refilling. This remote control — also designed by Fraunhofer researchers — will also allow doctors to adjust the amount of drug or the frequency or timing of its administration as required.

'Another advantage is that the patient does not have to swallow. The drug is just absorbed into the blood through the mouth which makes it much more effective,' he said.

Velten said that as part of his team's next project it may be possible to look into developing a wireless connection that allows the remote monitoring of the patient's dosage.

The next stage in the current project is for new Intellidrug prototypes to be built and tested. A prototype will be presented for the first time at the MedTec trade fair in Stuttgart at the end of this month. After testing, the system will undergo clinical trials on patients at hospitals in Berlin, Madrid and Naples.

These trials will test the prosthesis using a drug called Naltrexon, which is taken by drug addicts undergoing withdrawal therapy.